S 181.A2 4th 1914/ B 432221 _I I I, 15 It T!r r, kd. I.Y 'I #4 I I,I.. I i\ A f I,A I An' i f I' 4 Ii IC "'~ I k MIItm Pr I ^'\ il 4 I I 1..t 'i I 19 '8,. II /4 <s A I I r tI a? ;IIY 0^ opo __~~. u r:5'^ c S^M^^^^tf1~,,'~ -.^~i -41~A Rf g M 7fi~s a~~~~~W UN Of- ~~ WS,~~~~~~~~~~~~~~~Cs ley ~~~~~~~~~~~~~~~~a~~~~~~~~~~~~lY Y~ MV T A w;~~~~~~~~I~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~A4 ~~~~~~~~t~~~~~~~~~~~~~~~~~~~: ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ ~ O ss~~~~~~~~~~~~~~~~Z '44~~~~~~~~~~~~~~~~~~~~~ ~~~~~~~~~~~~~~~~~WF~~ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~l IRV 'f~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~t-~~~~~~~~~~~~~~,:R4~~~~~~~~~~".. lN, N U.,Vg W~ py,~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ -Vk~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~~~iP~ ~~~:fi~~~~~~~~~~~~~~~~~~A MCI~~~~~~~ aN toll~~~~~~~~ kv, A ~ s~: M i Ai. GOVERNMENT OF PORTO RICO BOARD OF COMMISSIONERS OF AGRICULTURE RIO PIEDRAS. P. R. FOURTH REPORT OF THE Board of Commissioners of Agriculture OF PORTO RICO FOR THE PERIOD FROM JULY 1. 1914, TO JUNE 30. 1915 SAN JUAN, P. R. BUREAU OF SUPPLIES, PRINTING, AND TRANSPORTATION 1 910 I LCF EXCHANGE LIBRARY STATE Ct '. OF WAtHir,. 4 1 _ I TABLE OF CONTENTS. Page. Report of the Secretary and Director --- —------------------------------- 9 Report of the Quarantine Service --— ___ --- —--------------------- 14 Report of the Chemist ------------------------------------— _ 16 Report of the Entomologist --- —---------------------------------------- 17 Report of the Plant Breeder_ --- —------------------— _ --- —----------- 22 Report of the Pathologist __-_ --- —----------------------— _ 33 Report of the South-Coast Laboratory ---------------------------------- 45 Report of the Tobacco Insect Investigations --- —------------------------- 50 Publications available -------------------------------------------------- 52 8 Government of Porto Bico Board of Commissioners of Agriculture. Rfo PTEDRAS, August 10, 1915. MR. Trilo TLARRfNAGA, President, Board of Agricdlture, San Juan, P. R. SIR: I have the honor to submit herewith my fourth annual report as Secretary of the Board of Commissioners of Agriculture, and the fifth report of the activities of the Insular Experiment Station, formerly the experiment station of the Sugar Producers' Association of l'orto Rico. Respectfully, W. V. TOWER, Secretary, Board of Commissioners of Agriculture, Director, Insular Experiment Station. Approved for publication. TULIO LARRINAGA, President. 5 I I ORGANIZATION BOARD OF COMMISSIONERS OF AGBICULTUEE. TULIO LARRINAGA, President --- —-------------------— San Juan JORGE BIRD_ ------- --- _ ----------------- Fajardo E. G. MILLER- ------- --- ------- - _ _ San Juan H. H. SOOVILLE__ _ --- —----------------— San Juan JOHN FRESE____ --- —_ --- —-— S ---____ --- —--------— San Juan D. W. MAY-_ ---------- -- ---------- -- -- Mayagiiez EDUARDO GIORETTI — --------------------------------- San Juan STAFF. INSULAR EXPERIMENT STATION. W. V. TOWER —... --------------— _D -Director W. E. CADY _- -------------------—.Chemist G. N. WOLCOTT_ _ --------------— Entomologist H. B. COWGILL__ _ _ --- —---------------— _ Seedling Expert J. A. STEVENSON __ --- —--— Pathologist and Botanist E. G. SMYTH -_As_ ----_ --- —---— __ ------ _8istant Entomologist G. B. MERRILL --- —-------------------------— Assistant Entomologist R. C. SILVA — ___________ --- --------— _ tenographer and Translator R. H. VAN ZWALENBURG-___ --- —--------— nspector, Mayagiiez J. J. DE BARRIL_ _ --- —----------— Inspector, Ponce PEDRO RECHANI — _ ---- - _ --- —------ Deputy Inspector, San Juan RAM6N BRANDES ---- ------------- -— Deputy Inspector, Mayagiiez l REPORT OF THE SECRETARY AND DIRECTOR. [ W. V. Tow IBR. INTRODUCTION. The Board of Commissioners of \griculture assumed temporary direction of the Experiment Station of the Sugar l'roducers' Association of Porto Rico on.May 15, 1914, pending the formal transfer of tie property to the Insular Government. Final details were completed and the formal acceptance by the Government of tile Experiment Station made Septe'nber 12 of the same year, tile staff being retained without change. The secretary and entomologist was made director, and the designation of the Station chatiged to "Insular Experiment Station." CONTEMPLATED ACTIVITIES. It is the plan of the Board to carry on without change the projects established under the former regime, suchl plans indeed having been provided for in part in the act of the Legislature accepting the offer of the Sugar Producers' Association. It is, however, felt that the work must by no means be confined to sugar-cane but that there must be a general broadening of the station activities to include other Porto Rican crops. The Board of Agriculture had already made considerable headway with a study of tobacco insects and means of control, a line of work which will likewise be retained. In addition, as rapidly as time permits and funds become available, studies will be undertaken with the various fruits of commercial importance, and with the growing of vegetables and other crops. In fact, the entomologist and pathologist have already given much attention to the insects and diseases of citrus fruits and pineapples. It is planned to establish an experimental citrus grove, and to make pineapple plantings as soon as the land is available. This will permit of variety tests, and fertilizer experiments, as well as providing suitable plots for the study of control methods of insects and fungus diseases. QUARANTINE SERVICE. The quarantine service has been continued without change. As in previous years inspection has been made of all living plants and 9 seeds entering the Island, both from the United States and foreign countries. Particular attention has been given to preventing the entry of tropical fruits as possible carriers of the dread Mediterranean fruit-fly or of other serious insect pests and diseases which are known to exist in other parts of the world, but which have not reached Porto Rico. By regulation of the Board of Agriculture the entry of living citrus material is prohibited, as well as the entry of plants and seeds of any description from those States known to be infected with citrus canker. CITRUS CANKER. At a meeting of the Board of Agriculture held in April, the citrus-fruit growers of the Island presented a petition requesting that a representative of the Board be sent to Florida for the purpose of studying the citrus canker, the steps being taken to control it, and the nature and'appearance of the disease. It was felt that first-hand knowledge of the canker was necessary in order that prompt recognition would be had of it should it appear in Porto Rico. And it would be only by prompt and energetic measures, taken before the disease had spread from the original infection, that the destruction of the citrus industry could be prevented. The secretary, in pursuance of this request of the growers, was authorized to proceed to Florida. Some two weeks were spent in studying existing conditions at various points in the State, and in particular in Dade County, which is the original center of infection. Special thanks are due to Mr. Burbank, of Miami, whose courtesy made possible a personal inspection of various canker-infected groves. Conferences were likewise held with State officials at the Experiment Station in Gainesville and with Federal officials in Washington. The situation as found in Florida appears very serious, and there may well be doubt cf the possibility of complete eradication. The greatest of precautions under strict quarantine regulations must be taken to prevent the entry of this disease into the citrus groves of Porto Rico, and to this end it is recommended that the power of the Board of Agriculture to make such regulations be definitely increased. CHEMISTRY. The chemist has been in direct charge of the fertilizer-control work. About one hundred samples of the commercial fertilizers offered for sale on the Island were collected and analyzed. Twenty-six per cent of them were not up to the guarantees given by the manufacturer 10 or dealer. A second series of samples will be taken during the coining year. The chemist has likewise cooperated with the plant breeder in the analyses of the juice of seedling canes, and has made a large number of various miscellaneous analyses. PL.NT DISEASES. The work of this department formerly entirely with the diseases of sugar-cane has this year been largely with citrus. Citrus scab which has caused so much loss to the planters has been given spe(ial attention. This disease has become prevalent in most of the fruit sections and has caused the loss of the entire crop to certain growers. Even when marketed scabbed fruit sells at a discount of from 50 cents to two dollars a box from the price of fancy fruit. Other agencies combined with scab are making it impossible for the growers to produce more than a very small per cent of fancy fruit, and it will be the aim of this Station to increase this percentage by the working out of systematic spraying schemes, and their use in demonstration work in the groves. ENTOMOLOGY. Of the various important projects planned by the entomologists of the Sugar Producers' Association, some have been completed as evidenced by the publications of the year, or important progress has been made upon them. With the entomological activities of the Board carried on before the taking over of the Experiment Station, progress has likewise been made. The sub-stations at Santa Rita and Aibonito for the study of cane and tobacco insects, respectively, have been continued in charge of the assistant entomologists. The life histories of the white-grubs of cane have been completed and information obtained on the important pests of tobacco, together with mleans of controlling them. The flour-Paris-green formula for control of the changa has proved most successful. The entomologist lhas devoted much of his time to a study of the moth stalk borer of ca ne. PLANT BREEDING AND AGRONOMY. The Department of Plant Breeding last season raised 6,000 seedling canes. These seedlings were from seed of our best native canes, as well as from seed obtained by crossing native canes with imported varieties. The object of this work is to produce new canes that will 11 yield a greater tonnage per acre, an increased percentage of sugar, and be more resistant to disease than our native canes. By raising large quantities of seedlings and testing them under various conditions we will doubtless find the canes best adapted to Porto Rican conditions. The first year from the minute seed fron the "arrow" of the cane there is obtained a single stool of cane. From the thousands of seedlings thus produced only the most vigorous are selected and tested for sugar content. Those that survive this test are planted in twenty-foot rows. At the end of a year's growth they are again tested, and the most promising planted in two hundred-foot rows. A third test and elimination follows at the end of the third year. The survivors, now few in number, are planted in tenth-acre plots in order that a mill test may be made. In the following year a trial is made of the ratooning power after which any that have proved themselves superior to standard varieties are sent out to various localities for further field tests. Because of the limited amount of land available on the station grounds, it seems best to carry on as many of the variety tests as possible, in co-operation with the various centrals and colonos. This moreover, gives the station much valuable data regarding the various cane-growing districts, and in particular is a means of ascertaining which canes are( best adapted to the various localities. The planters also become more interested in the new canes through this method, and keep in closer touch with the work. This year ten of the most promising varieties have been planted so as to be available for distribution in 1916. Barbados, Demerara and Trinidad seedlings are being tested and used by various centrals and colonos on the Island. In a survey made by the Plant Breeder it was found that 16 varieties are being cultivated on a field scale, and of these ten are comparatively new to the Island. Of the twenty-nine centrals visited, eighteen are trying one or more new varieties. Fertilizer experiments on cane have been started at a number of places and others were planned for the coming season. Most of these, however, have been dropped because of the scarcity and high cost of fertilizers. Mixed fertilizers can be obtained but the separate ingredients are most expensive and difficult to obtain. Lime has proved very beneficial to the growth of cane at the station. The results of experiments conducted indicate that the effect of a single application continues for at least three years. 12 CHANGES IN PERSONNEL AND STAFF. Mr. E. M. Bainter, lPresident of the Board, resigned April 28, 1915, and Mr. Tulio Larrinaga was inadI& acting president until aI new president should be named. The San Juan office of the secretary and entomologist has lbeen discontinued land the assista it quiarantine inspector given desk room in the office of the Burean of Information..Mr. John R..,Johnston, 'anthologist, resignd in September. to accept a position with the Experiment Station of the Cuiban Governmacnt and was suceceeded by Mr. John A. Stevenson. formerly assistant pathologist. Mr. Thomas IL. Jones, Entomologist, resigned to accept at position with the United States D)epartment of Agricuilture. Mr. 0. N. Wolcott, formerly traveling entomologist, w~as applointed hy the lboard to succeed him. PUBLICATIONS OF THlE YEAXR. Bidlietini 8.-IMiscellaneous Papers on ('ane and Fertilizers. by J. T. Crawley. Bdlletini 9.-Salts in Soils -,nd Waters of the South Coast of P~orto Rico, byv J. T'. CrawleyN -id IN. BI. Cadv. Builletitn l0.-The Entomnogenous Funigi of P~orto Rico, by.J. R. Job nston. Bullet~inI li.-Aphides or lPlant-Lice attacking Suigar-cane, Iby T. H. Jones. Bulletini 12.-Trhe Suigar-cane moth Stalk-borer, by rI. II. ~Jones. IB0lleini 13.-(Cotmmuercial Fertilizers, by W. B3. Cady. Bidlh tin 1.I. —The Suigar-cane Weevil RLoot B~orer, by TP. II..Jones (.'ireca lar 4.-Notice to Citrus Growers. (!ircidala 5.-Plant Qua rant inc Regulations. ('irecular 6.-Control of thme Clhanga, bv G. N. Wolcott an(1 S. S. Crossman. Third Annual Report. 13 REPORT OF QUARANTINE SERVICE. During the year the quarantine inspection work has been continued at the various ports of entry along lines laid down in previous years. All regulations have remained in force and in addition one covering the entry of citrus material was promulgated. As passed originally in December this regulation prohibited the entry of all living citrus material from Florida and the Gulf States. In April it was amended to include citrus from all parts of the United States, with certain exceptions, and plants and seeds of any kind from Florida and ether citrus producing States. Under this regulation various packages of plants have been intercepted and either destroyed here with the owner's permission or returned to the senders. These have included citrus trees from the canker-infected districts in Florida as well as citrus and other living plants from that and other States. It is not proposed to take any chances with a disease of the dangerous nature of citrus canker-a disease which has already cost the people of Florida several hundred thousand dollars, not including the destruction of thousands of bearing trees. It is now estimated that from two to three million dollars will be necessary to eradicate the disease in the United States. Because of the nature of the disease, it is felt that if once established in Porto Rico the citrus fruit industry would be completely ruined. The number of wild orange and other native citrus trees would make eradication impossible. Following is a resume of the inspections made during the year. Very little plant material from countries other than the United States has been entered, steamship service still being more or less interrupted. SEED AND PLANT INSPECTION. PLA NTS July Aug. Sept. Oct. Nov. Dec Jan. Feb. Mar. Apr. May J.lune Bulbs................. 14 25 2 1 3 13........................... Carnations............ 22...... 7 4 1 12 42 24 36 46 80 126 Chrysanthemums........ 10 24..... 40 Dalhias........................24 30 102 121 40 94 Ferns................ 27 27 3......... 2... 2 2 12 22 6 17 Geranlnmms......... 4 4...... 18 2...... 24...... 10 34 84 52 Palms..6 6 3... 4 2...... 15 4 8 Roses.......... 23 258 140 159 158 75 75 144 172 185 291 652 Sundries.................... 1 2 1 50 24 20 10 60 132 95 143 14 EI 'DS 'aklages-Packages July.................. 235 J an ary.............................12 August................12 February....................,.24 September.............. 350 M arch............................... 14 October............................ 127 April............................. 14 Novem ber.......................... 136 M ay................................ 40 December............................... June......................20 MISCELLANEOUS ARTICLES. July-31 bunches cut flowers, 3 bottles honey, 10 pieces of sugar-cane. August-12 queen bees, 13 miscellaneous plants. September-18 queen bees, 1 package bird seed, 15 miscellaneous plants, 1 piece yautia. October-1 sample coffee, 15 miscellaneous plants. November-Nothing. December-Nothing. January-2 pieces of cane. February-1 tree, 2 boxes of miscellaneous plants. March-12 miscellaneous plants, 24 samples of vegetable extract, 1 bunch of cut flowers. April-2 trees. May-1 box miscellaneous plants. June-3 pounds plant food. FRUIT AND VEGETABLES.1 July-10 mangos, 22 oranges, 10 melons, 2 samples of beans, 17 samples chick peas. August-25 bananas, 6 melons, 12 pears, 1 pineapple, 24 pomegranates, 2 samples chick peas. September-88 apples, 4 aguacates, 2 boxes grapes, 10 melons, 37 pears, 14 pomegranates, 1 box potatoes, 7 packages figs. October —11 aguaeates, 15 apples, 13 baskets grapes, 19 melons, 17 oranges, 12 pears, I pomegranate, 2 pineapples, 2 pinos. November-1 basket grapes, 40 apples, 10 nisperos, 12 peals, l pino,;) pomegranates. December-24 nisperos, 4 lemons, 6 oranges, 2 pineapples. January-4 lemons. February-Nothing. March-15 oranges. April-70 bananas, 5 oranges. May-4 eggplant, 11 mamey-zapote, 1 mango, 4 oranges. June-48 nisperos. 1Tropical fruits and vegetables seized and destroyed. 15 FUMIGATIONS. Very few fumigations have been necessary, plants arriving quite free of serious insect pests or diseases. A marked improvement over conditions of previous years.... MAYAGUEZ, JULY, 1914, TO JULY 1, 1915. Shipments inspected -------------------------------------- 12 Shipments destroyed --- —------------------------ 1 REPORT OF THE CHEMIST. [By W. B. CADY.] During the year just past the work of the department has been continued along the same general lines as indicated in the third report. Much of the time has been given to the fertilizer control work. Samples of the various commercial fertilizers imported into the Island were taken and analyses made, the results being published, together with the fertilizer control law, as Bulletin 13 of the Insular Experiment Station. It is to be noted that a large number of these samples were found to fall below the guaranteed analyses as given by the manufacturer or dealer. Determination of the sugar content plays a very important part in the selection of seedling canes for further trials. In the course of this work one thousand and ten analyses of the juice of seedlings under test were made in co-operation with the plant breeder. In addition a large number of miscellaneous analyses were made for other members of the staff, and for various outside parties as included in the outline below. ANALYSES MADE BY THE CHEMIST, 1914-1915. Analyses of tobacco (complete) ---- ----------------— __ ----_ _ 5 Analyses of tobacco for arsenic and lead --- —-----------— _ —_- - 7 Analyses of tobacco lead arsenate --- —------------------------- 3 Analyses of water, for irrigation — __- ____ --- —------------- 6 Analyses of lime ------------------ -------------- 4 Analyses of limestone__ ---_ --------------------- 3 Analyses of soil for lime__ —______ ___ --- —----------— __ ___ 48 Analyses of soil (complete) ----------------------— _ --- —-______ 6 Analyses of wood ashes -— _____________ --- —---------- 4 Analyses of cachaza ash _ --- —— _ --- —------- ___ ---__ --- —----- 2 Analyses of guano. --- —---------------------------------— ____ 21 Analyses of deposit on lake -__ —_____ --- —-- _._____ — _ 1 Analyses of commercial fertilizers _______ ____________________- - 150 Analyses of sugar cane for plant breeder ________ --- —---------- 1, 010 Total analyses for the year____________ --- —------- - 1, 272 16 PROJECTS. It is proposed to devote the coming year to the following general projects: 1. Collection of samples of all fertilizers and fertilizer ingredients offered for sale on the Island and their analyses. (Under the provisions of the fertilizer-control law.) 2. Determination of sucrose content of seedling canes. In cooperation with the plant breeder. 3. A study of the relation of the various soil types of the Island to the production of citrus fruits. 4. The analysis of miscellaneous materials, such as lime, water, soils, etc., sent in from time to time by agriculturists of the Island. REPORT OF THE ENTOMOLOGIST. [By GEORGn'N. WOLCOTT.] In June, 1914, Mr. Thos. H. Jones accepted the position of entomologist at the Insular Experiment Station, Rio Piedras, P. R. His time until his resignation in September, 1914, was very fully occupied with taking care of the correspondence that had accumulated in the months during the spring when no entomologist was present at the station, and in preparing for publication the annual report of the entomologist for the fiscal year ending July 1, 1914, and three bulletins: "Aphides or Plant-Lice Attacking Sugar Cane in Porto Rico," "The Sugar-Cane Moth Stalk-Borer, Diatraea saccharalis Fabr.", and "The Sugar-Cane Weevil Root-Borer, Diaprepes spengleri Linn.", which have been issued as Bulletins No. 11, 12 and 14, respectively by the Board of Commissioners of Agriculture. These' publications are summarized below. He also was able to nearly comn plete a paper on the scale insects of Porto Rico and one on the sugarcane cutworms and grassworms of Porto Rico. These papers are the results of investigations initiated by Mr. D. L. Van Dine and brought to completion by Mr. Jones while connected with the Sugar. Producers' Association Experiment Station, and'.the acquisition by the Board of Agriculture of these completed papers on the important economic cane insects of Porto Rico exceeds in. value any of the material entomological equipment in the station obtained from the Sugar Producers' Association. SU1MMARY BULLETIN NO. 11. Two aphides or plant-lice are known to attack sugar-cane in Porto Rico. Of these the yellow sugar-cane aphis (Sipha fiava Forbes) 17 is of greater importance as a cane pest. The other, the brown sugarcane aphis (Aphis setariae Thos.) is not common. Sipha flava is known in the United States as a pest of various plants belonging to the grass family. In Porto Rico it has been found to attack, in addition to sugar-cane, sorghum and "Ilemon-grass." The other aphis has been found only on sugar-cane. The yellow sugar-cane aphis occurs on the under surfaces of the cane leaves, especially on those which have begun to bend over. The brown sugar-cane aphis occurs at the junction of the leaf-sheaths and leaf-blades, on the lower surface, and on either side of the midrib. As found in the field both aphides usuallv occur in such situations in small groups or colonies, composed largely of wingless forms of various sizes, and a few winged individuals. Both aphides are small in size, the largest measuring only about 2 mm. in length, and their structure can only be clearly made out by the use of a magnifying glass. The aphides injure the plants by removing the plant juices through their beak-like mouth parts, which they insert into the plant tissue. The two aphides are attended by various ants, the latter obtaining from the aphides an excretion known as "honey dew," which they use as food. In the case of the yellow sugar-cane aphis this attention is more or less accidental, but a close relationship exists between the "fire ant" or hormiga brava and the brown sugar-cane aphis, the ant constructing earthen shelters around the aphis colonies. The yellow sugar-cane aphis is known to be preyed upon by a fungus, five lady-bird beetles, syrphid flies and a lace-winged fly. The brown sugar-cane aphis is known to be attacked by an internal parasite, a lady-bird beetle, and a syrphid fly. Because of the effectiveness of the natural enemies of both aphides, the use of artificial measures of control in the field is inadvisable especially because of the difficulty and cost of applying satisfactory remedies. The aphides discussed in this circular have been previously recorded as injurious to sugar-cane in Porto Rico, but in these references they are given other names than those now used. SUMMARY BULLETIN NO. 12. The sugar-cane moth stalk borer (Diatraea saccharalis Fabr.) occurs in many tropical and sub-tropical countries and attacks a number of plants other than sugar-cane. It is often an important pest of corn. It is distributed throughout Porto Rico. 18 The principal loss to sugar-cane caused by the borer is the loss in sucrose resulting from the work of the larva in the stalks. In addition it reduces the germination of the cane by destroying the eyes and also causes "dead heart" in young cane. The eggs are deposited il clusters on the leaves of tle cane and hatch in about five days. Tile larval stage, spent in the stalks, consumes from twenty to thirty days. The time spent as pupa in the stalk varies from seven to ten days. Two parasitic enemies of the stalk-borer occur in Porto Rico; one an egg parasite (Triclhogranmma minutml1t Riley), the other a Tachinid fly (probably Hypostena sp.). A parasite fungus, Cordyccps barbcri Giard, attacks tile larva. M1any other enemies of the insect, not known in Porto Rico, occur in other countries, and efforts are being made to introduce some of them into Porto Rico. The preventive methods of control advised to reduce injury by the borer include planting of non-infested seed, simultaneous planting and harvesting of large areas of cane land, and clean cultivation before and after planting. The remedial measure of control include the collection of eggclusters and the cutting out of dead hearts. The burning of trash as a means of reducing injury is not to be recommended and the use of traplights as a means of capturing the adults does not seem advisable. At the time of harvesting, all stalks cut in the field should be taken to the mill and ground in order that the numbers of the larvae and pupa be reduced. SUMMARY BULLETIN NO. 14. The sugar-cane weevil root-borer (Diaprepes sprengleri Linn.) is apparently generally distributed throughout Porto Rico, but the larvae or grubs seem to cause most serious injury to cane in the lands on the south coast between Guinica and Aguirre. The larvae or grubs injure the root system of sugar-cane by pruning off the small roots and by tunneling into the root-stalks. This injury has a very serious effect upon the cane, causing a stunting of the growth and in cases of severe infestation resulting in the death of the plants. Severe injury is usually confined to small areas and above ground the injury is similar in appearance to that due to other causes, such as white-grubs and rhinoceros beetle grubs. By an examination of the root-stalks, however, the work of the root borer can be identified by the characteristic tunnels. 19 The adults feed upon a variety of food-plants. Of these so far noted the jobo is preferred. The eggs are laid in elusters between parts of the same leaf or of two leaves, the surfaces al)out tile eggs being held together by an adhesive substance. In the ticld the eggs, for the most part, seem to )e l)lacedl on sugar-cane and various grasses. The larva or grub enters the soil immediately after issuing from the egg, and it is in this stage that the insect injures the root-system of the cane. 0 Tile pupa-the quiescent stage between larva and adult-occurs in an earthen cell in the soil. Notes on the length of time passed by the root-borer in the soil as larva, pupa, and adult are not complete, but it appears that the beetles which develop from eggs laid at any one time are not themselves ready to deposit eggs until about a year later. Apparently there is an overlapping of generations. The beetle lives for a considerable time, the females apparently longer than the males. One female collected in the field and kept in confinement, remained alive froin July 29 to November 8; another from August 15 to November 7. During this time the latter individual deposited 400 eggs. A number of birds feed on the root-borer and should therefore be protected and encouraged to breed about the cane-fields. Lizards are probably also beneficial in that they reduce the numbers of the pest. The collection and destruction of the beetles and grubs is recommended as the best means of control we are now able to advise. While beetles probably occur on their food-plants throughout the year, there are times when they are much more abundant. Such periods seem to depend somewhat on the locality. At Rio Piedras we have found themn most plentiful during October, November and December. The grubs, pupfr, and adults that occur in the soil may be collected at plowing time, or in cases of serious infestation the affected stools may be removed and the grubs, pupa and adults that are found in the soil and in the root-stalks destroyed. In either case the root-stalks should be immediately destroyed if the grubs are found working therein. The cutting and burning of grass around the cane fields may be advisable in cases where the eggs occur in numbers on the grass. 20 Incomplete experiments indicate that the beetles can not be satisfactorily killed by applying poison to tie plants upon which they feed. Mr. George N. Wolcott. traveling entomologist of the board, upon returning in Septelmber, 1914, from leave of absence, was emplo.led during til early fall in Illinois collecting tile cocoons of Tipihiaa parasite of white grubs. l)espite tile scarcity of fields being plowed because of drought, 343 cocoons were collected during the short period lie was in Illinois. These cocoons were left in cold storage in Illinois, to be forwarded to Porto Rico in the spring. Following the resignation of Mr. Jones, Mr. Wolcott was appointed entomologist of the station and in October 21, 1914, arrived at Rio Piedras. Following a preliminary trip around the Island, when many of the centrals were visited, and several local trips, it was decided that the most ilmportant work to be done was to learn the abundance of the smaller moth stalk 1)oier, )iatra'ca, in all c'alle-producil(ng siections of the Island and determine what factors limited the abundance. This work of determining the status of Diatraea was systematically carried on throughout the grinding season of 1914-1., and all parts of the Island were visit(ed for longer or slorter periods. The resullts of this investigation are soon to b)e published by the board as a circular entitled "Tlle Influence( of Rainfall and tile Non-Burning of Trash on the Abundanee of Diat)an a sacchara lis."T T1he summary and conclusions of this circular are to the effect that the abundance of Diatraca is in inverse prolportion to the am(,unt of rainfall, and that the infestation of the cane by the borer is increased nearly 100 per cent in fields where the trash was burned after the preceding crop. To allow Mr. Smyth, the assistant entomologist located at Santa Rita to come to Rio Piedras and take necessary photographs of the white grubs of Porto Rico for publication, Mr. Wolcott exchanged places with him for a month during November-December, and besides taking care of the white-grub breeding work, was able to make observations on the status of Diatraea and start the inspection of the Guanica Centrale cane boats from Santo Domingo for the 1914-15 grinding season. In May, the Tiphia cocoons arrived from Illinois in cold storage, and to take personal charge of the liberation of the adults as they C1ircnlar 7, Insular Experiment Station 21 emerged from the cocoons, Mr. Wolcott spent half a month at Santa Rita, allowing Mr. Smyth to again do photographic work with the equipment at the station in Rio Piedras. The results of this emergence were very satisfactory, for, due to the excellent care the cocoons had received in Illinois and en route, they arrived in perfect condition and 71 per cent of the adults emerged within 10 days. The highest percentage of emergence previously obtained was 44 per cent. Although there are no indications that Tiphia has yet become established in Porto Rico, now that the proper methods of collection, preservation during the winter and transportation in cold storage are known, the chances of ultimate success of the introduction and establishment are much better. All of the 243 adults which emerged from the cocoons this spring were released in a field where white grubs are known to be abundant, and conditions seemed most favorable to the parasite. During the latter part of the fiscal year, much miscellaneous office work in Rio Piedras, which in many cases was a year or more behind, was brought up to date. Several trips were made to near-by citrus groves in company with the pathologist, making preliminary observations towards formulating a citrus spray calendar for the control of insect pests and fungus diseases of citrus trees. A demand from several cane growers for information on the successful methods of control of the changa, Scapteriscus didactylus, has led to the immediate publication of Circular No. 6, in advance of the complete bulletin by Mr. S. S. Crossman, on the results of his work on tobacco insects, carried on at Aibonito. This circular was based on the work of Mr. Crossman and was written by him, but was revised and adapted to sugar-cane and vegetable crop conditions by Mr. Wolcott. REPORT OF THE PLANT BREEDER. [By H. B. COWGILL.] INTRODUCTION. The work in plant breeding and agriculture has been carried on during the past year along the lines previously planned and as outlined in the Third Annual Report. Variety work has been given the most attention. The demand for new varieties for trial and cultivation has been good, showing that there is much interest among the cane planters in improved varieties. There are a few kinds of cane which have shown themselves superior on the fields of this station and at a few of the centrals to those commonly grown on 22 the Island, and they deserve to be more carefully tested out on the plantations. One new variety experiment was commenced during the past year, the first year's results of which are given below. The work of production of new varieties from true seed is being carried on as fast as possible, it being believed that natural conditions here will aid more or less in selecting the best seedlings for cultivation. While the same factors may have an influence on the selection of introduced varieties, there are only a few of them to be selected from, while with seedlings raised here the number is large. Some seedlings were secured, during the past season, as a result of efforts to crosspollinate the varieties. These efforts were so evidently successful as to leave little room for doubt of the fact, and it tends to verify the belief that the method adopted is a feasible one, which if followed up for a series of years will yield hybrid varieties of cane. The field experiments other than with varieties of cane have been carried on as far as possible as proposed in the Third Annual Report. Besides those which were already under way, a series of experiments on cultivation has been started. The work during the past year has assumed three different phases, as follows: 1. The supervision of seedling production and breeding work, including the selection of varieties for parents, selection of seedlings for furtler propagation, cross-pollination experiments,:atl( some research which has a direct bearing on the work. As the sugar-cane flowers in the fall and early winter considerable of this work had to be done at that time. 2. Travel to different parts of the Island, for the purpose of ascertaining (a) The different conditions for cane growing in the various localities and the varieties suited to each. Several of the centrals are trying varieties which have been received, either from this station, or from some other source. On some of the sugar estates certain of the new kinds are being extended as rapidly as possible and are giving very good results. Twenty-nine of the centrals of the Island were visited during the year. Out of this number eighteen had one or more new varieties under trial. Data secured from tests at this station and from other places upon the characteristics and requirements of the new varieties assist in sending the varieties from this station to localities where they are most apt to give good results. 2'3 (b) To extend to the sugar estates information which llas been obtained at this station concerning cane cultivation, especially as to fertilization. For t1is l)urlpose, and to test thle reqluircllnents of the soils in these localities arrangeiments have been lalde to conduct co-operative fertilizer experiments at some of the sugar estates during the coming year. 3. Supervision of field experiments of the station, which include fertilizer tests, variety experiments and cultivation experiments. CANE BREEDING WORK. There are being cultivated at this station at the present time four generations of seedling canes, which are undergoing from year to year, a process of selection land elimination. Those produced in the year 1911-12 have been reduced in nunber to 125. Of those raised in 1912-13 we have now about 350(. Tlie 10,000 propagated in 1913-14 have been reduced to 504. 1)uring the past season about 6,000 new seedlings were raised and saved for further propagation. In general, the seedling canes raised lhere have shown much vigor. By the process of elimination those which do not show themselves to have superior characters of growth are discarded. Clhemical analysis of each selected seedling is also nlade each year, it being expected to use these successive chemlical analyses inl imaking the final choice of seedling varieties to be extended to the estates of the Island. CHOICE OF PARENT VARIETIES. As would be natural to expect, it has become evident in the progress of the work that some of the varieties of cane, when used as parents of seedlings, produce very much better offspring than do others. In 1913 it seemed that the proportion of superior seedlings raised from seed from the tassels of some of the varieties was very much larger than that from others. Accordingly, it ihas been the aim to test out different varieties of cane in order to find thos, from which the best seedlings can be produced, it being more or less probable that the varieties which produce the largest number of good-appearing firstgeneration seedlings which show a high average sucrose content determined by chemical analysis, will be the ones which will yield the best filial varieties. Following is a table (Table I) showing some of the parent varieties used each season during the past three years and the number and percentage of selected seedlings from each: 24 Table I.-Proportion cf selectsd seeclings Escured from parent varicties. Year P'i -cIl v, X rit, V Alrox. No. N1tim t I't.r ct1li ralstl s.<t'lte(l stle(' l tl I I t ht. ll'. t................................ 1 1. 1911-12 - I, l.............................;:t!'.9 I 1; 17....................................: 1. 1 27 4I )1, I................................. 12. I I 7.......................... ''................................... | BIt:;7l!;l I..,........... '(S.12 1.64K) 1;) 5.................... 1. 3 5.o I:;2 I.27.................................. 1.4.4 191-11 I '!'................................ 2,70 I 4. I I.1)....................................: 1...................................... 1,6 7:3 4W6 8.94 [ '1' 1,1()() 82 7.15 'I his?St 71 was set-curt (I frioi Mr. ('. T. Murphy, t In of (;iu nica C nt'lr:tl, 1bul t1he 11;1iinn ill whlilch it \was s(c'til' '1 is lnot kliown 1l. A personal estimate as to the relative value of the (litferent vilrieties as parents from the work so far as conducted differs to a certain extent from that indicated by the above figures, as allowance is made for the unfavorable conditions under which the seedling from some of the varieties grew, which made them inferior in appearance and prevented them from being selected in as large numbers. Had they been selected they would have had less vigor to transmit to their succeeding generations. It has been the aim in all the work of selection to obtain seedlings Iaviing good( (lualities ill addition to thlose possessed by their parent varieties. That is to say, if the parent variety is a high sucrose cane but one which yields a relatively small amount of cane per acre, effort is made to get seedlings from it which have the good qualities of the lparent variety but which also produce an abundance of cane. CROSS-POLLINATION EXPERIMENTS. An effort was made during the past year to obtain seedlings from cross-pollinated seed. It is believed that by this means there is a possibility of combining the good qualities of two varieties in the seedlings, and obtaining also increased vigor. Experiments of this kind have been tried in other localities at different times. Emasculation and hand pollination have not proven successful, because of the smallness of the cane flower, the height at which the inflorescence is produced and its brittleness. This method was tried by Lewton-Brain in 1904, and Stockdale in 1905, in the British West Indies. The former succeeded in obtaining six hybrid seedlings only. 25 In view of the small percentage of the seedlings which develop into superior varieties, it would seem to be very improbable that there would be any of value in so small a number as this. The attempts of the writer, during the past year, have followed the method tried, among others, by Mr. J. D. Kobus, in Java. By this method he is reported to have obtained two seedling varieties recognized as being of value The varieties to be crossed are planted in parallel rows, with a pollen-sterile variety on the leeward side of one which is pollen-fertile and which blooms at the same time. A large number of seedlings were produced from the tassels of the pollen-sterile variety and there can be little doubt that they were from cross-pollinated' seed. The pollen-sterile variety in this case was the Otaheite and the pollen-fertile parent B 347. Ordinarily the Otaheite cane produces tassels with a very small proportion of fertile seeds. All attempts previously made with it here have given a very poor germination and very few seedling canes. This year, with B 347 growing on the windward- side, and both flowering abundantly at the same time, the'germination was excellent. This is a good indication that the flowers were cross-pollinated, and very probably almost entirely by the adjacent variety, B 347. Because of the way that the stigma lobes project from the glures, cross-pollination seems to be very easily possible. Another method was also tried here with some success. It consisted in tying together the tassels of the varieties to be crossed, before the florets of either open. Crystalina and D 109 were the varieties used, Crystalina being the pollen-sterile parent. A smaller number of seedlings were produced by this means, but the results were equally satisfactory. There is rather more certainty of getting crossed seed by this method. There is perhaps slightly more liability of the seed of the pollen parent becoming mixed with that of the pollen-sterile variety, but this is not a very serious matter, especially as the tassels of the two varieties naturally soon grow apart and are not usually together when the seed is in a condition to be shed. CANE VARIETIES GROWN ON THE ISLAND. At different times during the past year the writer made trips around the coastal-plain area of the Island, and visited at the same time the fields of the sugar centrals in that region. The varieties of cane found cultivated on an extensive field scale were the following: 26 Otaheite (White cane) Gigalntiw B 1355 Striped I) 117 B 1030 Crystalina 1) 109 B 1753 Cavengerie (Red cane) I) 625 G(C 493 Penang B 3412 Yellow Caledonia B 20S Figures were not obtained as to the acreage of each variety, but from a personal estimate the kind most extensively cultivated is the striped cane. The next in importance is apparently the Otaheite or white cane; with Crystalina coinig third. Many other varieties are being tried on a less extensive scale by some of the centrals and haciendas. Yellow Caledonia is attracting the widest attention at the present time. It is under trial on estates in nearly all parts of the Island except the south coast. In some places the acreage of this variety is quite extensive, while in other localities it was introduced for the first time during the past year. It is being tried on the estates connected with at least fifteen of the centrals. Among those who have it under trial there is a wide difference of opinion as to its value and suitability to conditions here. In general it is gaining in popularity, and by some it is now considered a very promising cane. Places where other new varieties are finding favor are Gu&nica Centrale, Central Fajardo, Central Mercedita (Ponce), Central Fortuna, Central Loiza, Estate of H. I. Sewell, Humacao, and Central Los Canlos. New varieties other than Yellow Caledonia are being tried at estates connected with eight of the centrals not included in those mentioned here. Among the kinds not already mentioned which are giving promise are B 3922, Seeley Seedling, and B 6450. The striped cane is the variety most commonly grown on the north and west coast; the Otaheite is most common on the south coast; while the Crystalina is the variety mainly grown in the southeast part of the Island. Porto Rico, as a whole, presents a very wide range of climatic and soil conditions. Cane is not grown in every locality, but even in the cane regions there is a wide range of environment, which mus't have an effect on its growth. The amount and distribution of rainfall, the topography, and the chemical and physical conditions of the soil are the most important factors, while heat, light, and wind have a greater or less effect.. These factors must also have an influence on the kind of cane grown, as different varieties are without doubt naturally suited to varying amounts of these growth factors. We know from observation that this is more or less true with the varieties here. Among the new varieties it is 27 impossible to say that any one of them is the best, because they have differt nt ch.araecteristics wvliic iiake tlein stlitable for different locta! conditions. Th'I'is work hias gone only far enoiughl to make it possible to r(e(,oml,..e(d certain varieties for (,ertain local conditions, becaulse of thlie icoll'tirging resullts obtainild by a few of the cenitrals andl on the fields of this station. RESULTS OF FIELD EXPERIMENTS. Varieties of canec.-Thi,- station has had several varieties of cane under cultivation, during the past year, in variety tests and plots for distribution. The variety most widely distributed has been the Yellow Caledonia. Variety tests have been made in tenth-acre or twenty-acre plots. The cane obtained from each plot has been carefully weighed and analysis made of the juice from the crusher of the Central Vannina mill. In many cases there is a great difference noticeable between the varieties before harvesting. This difference has usually been most evident with the ratoon crops, showing that. some of thlem are very much better ratooners than others. The third crop of cane was harvested from the variety experiment reported upon in the last annual report. The following table (Table II) shows the yields of cane per acre for the plant cane, first and second ratoons, and the average of the analyses of the juice for the first two crops: Table II.-Comparative yields and analyses of variety canes, plant cane, first and second ratoons Tons per acre lirix Scrose Purity -- -a-veag'i I ve rage javerage Name 1st and 2d lst and 2d ( st and 2d Plant Ist 2d Total crops crojps crops cane ratolops ratoons D 109................... 36.57 24.55 17.60 78.72 18.12! 1..98 87.0 Yellow C(aledonia........... 29.35 7.5.... 1721 1.85 85.9 Otahelto (White)............ 4.93 15.80 10.50 68. 21 14. 6 2 11).98 82.2 Seeley Seedling............. 4585 36.35 25.95 108.15 16.86 11.8 B 328........................ 31.01 15.80.05 55.8 16 5. 25 89.8 1)116....... 63.60 50.70 35.95 150.25 *15.56 *12.1 75.1 B 3696........... 26.'5 1935 11.80 57.50 16.5i1 1 4.17 1 85.7 Crystallna.................. 1(.87 23.70 77.52 16.60 15.02 90.5 Cavengerel................. 51.53 41.00 2390 121.413 16.77 12.45 75.3 D 625........... 5627.1-1.46 28.52 129.25 14.96 10. 65 I 71.1 1 376.....................37 i 30.35 14.10 81.12 17.08 i 16.68 91.4 1 208.......................... 0.46 15.0 21.37 70.13 8.12 16.90 91.5 B 4596........................ 51.9 31.87 21.70 108.50 5.3 12.73 84.2 B 3708...................... 27.86 1 5 7 10 4 81 18..1 17.27 93.6 1356..6............. 86 141.55 8.45 19.86 17.86 17 01 95.2 1) 117....................... 57.53 25.75 16.30 99.55! 17 50. 15.92 90.9 II 306 (1 347)............... 2 1. 2..................................................... B 1753...................... 50.22 35.75 19.75 1 105.72 1742 158 89.4 1355................. 2920 17.05 10 50 56 16.81 15.71 3.3 B 109........ 3459 i2425 14 70 73.54 17 32 15.61 89.8 Crysta a................. 36.51 '2230 9.10 68.21 18.10 +17.07 +94.8 Otaheite (White).......... 1.18 19.66 1160 72.44 + 16.80 +1.1.91 +88.7 Light Stripe................. 0.70.00 2.1.10 80. 0 14.1:; 11 23 78.5 White Transparent......... 45.52 1795 10.40 73.87 18.12 17.06 94.1 B 1376....................... 41.80 1 5.40. 9.86 67.06 185 18.20 94.8 P!nant cane. t 1st ratoon. 28 A few of the varieties were very noticeably better than the rest, as the above results show. Seeley Seedling has made a better showing than any of the others, considering the quality of the juice and the w\eightt of cane prolduced. B1 1753. 1) 117. 1) 1)09 ald 459t; have also given excellent returns. B 208 gave better results as a S'c'n11d ratoonl tliha ais first. Tllis caie is (lllite Slisc'tbltiitc o t tI effects of dry weather, and the past year has been much more favorable for its growth than the previous one. Tlle soil on whlicel this eXlperiien Ilt Wis cod(ltctett wa.s low lall clay loanyIl. Another experiment with introduced varieties more recently obtained was commenced during the past year on land adjacent to the one above reported. The plant cane was cut in the month of May, and the weight of cane and analysis of crusher juice secured. The results were as follows: Table III.-Comparative yields and analyses of variety canes, plant cane. Nallle 'l'tl (> HIls 1 e Brix (SucrIOs' i 'lrlity I: '859............................... 21'.10 16.63 1 I.'5; N7.S t I................................. 3 1.5 () 17.3 1.. B1 2................................:7.10 16.33 11.75 I.3 1 8t';)..................... 22. 1 18.01 I 1 l. H:.5 1 71!69......................... 19. 17.83 1 |. l 2.7 B: 6311 1.........8.................. 19.83.1I 92 ) 7.1............................. I. 17.90 Ii:!1.2 O t th ie.I............................ 1.('fi. j > 1. B 319: I................ I.... 1 8.. 17i.10. 7.; ii 6536............................... 1!. l) 1...75 ':.F.5 B 6385................. I ' 17.17 1 1 M.l,. B 34t).........................). 17.07.2I H!.:. 1578................................' 17.40 8I 1.,0!H'.8 'st................ 22.1 17.1!8 I; 5!]12.0 1:1:................................. 1... 1.7. B f01.N............................. ' 1..37 I '.35 6. 37 17................................. 6. 71 19!.19 17.8l 92.8 B 68 5................................ 17 I8.15 1 2 1(D iam on - l 5....................... 21. 7. 1 7 37>.5 1B 7215...........................!:. 0.0 18.6- 1 7.0 92.8 Among these canes the following are promising: 13 809. B 7245, B 6292, B 3859, B 3405, and B 3747. All of these varieties yielded higher in this experiment than either Crystalina or Otahclite, which were used as checks. Green manure crops.-In many parts of the Island it is the customn to rest the land after it has been cropped to cane for a series of years. It is then allowed to go back to grass naturally, or is planted to malojillo, (lPanicuml barbiiodlc), or Guinea gras (P'i.i. cum maximum). Cattle are usually grazed on the fields during this period, or the grass may be cut and sold or fed. The condition of the soil is improved by this means. Leguminous crops are better soil renovators than other kinds, as they have the power of fixing 29 atmospheric nitrogen in the soil. If legumes can be found which are adapted to Porto Rican conditions and which will furnish forage for stock: it may be possible, by their use, to shorten the period during which the land must be rested and with the same or greater benefit. A crop for this purpose must be a vigorous grower, preventing the growth of weeds. It should produce albundant seed, of high germination and should be palatable to stock, as well as resistant to disease, adverse conditions and the effects of grazing. There have been several legumes under trial here during the past season. Some of them gave little promise for the purpose mentioned but may be suitable as green manure for other crops, while others are promising for green manures for cane. The following table (Table IV) gives a comparison between them as to germination of the seed, habit of growth, length of growing period, amount of seed produced and resistance to insects and disease, as they appeared in the one year's trial: 30 Table IV.-Comparative trials of leguminous cover crops. Name (;ermlnation Amount of Habit Growing period seed (haracter of I' ~ produced growi Injury by I}s'cls and disease Kuthi, (Dolicho blorus)................................... Fair........ Bushy............ 5-6 months........ Mung bean, (Phasenlus max)................................. God....... Bushy............ 6-7 months..... Moth bean, (Phaseeolus aconilifolius)...................... ood....... Sub-trailing..... 5-6 months........ Black velvet bean. (Stizolobiumi sp.)........................ God.......' Twining.......... 11-12(;) months... (C tnavalia gladiata)........................................ Fair........ Trailing.......... 8-9 Ilonths...... (Stizolobium sp.) (S. P. I., No. 21424)........................i Good....... Twining......... 11-12,2) months... Lvon bean, (Stizolobium sp.).............................. ' Good....... '1 wining......... 11 12) 2 molths... Cow pea, ( 'igna caajang)................................. Fair...... lushy.......... 12 months....... _ (Slizolobium aterrinium )............................... Good....... Twi ing........................... (,tizolobium capitatun).................................... Fair........ T ninnlg......... 1011 months..... Chinese bean (iStizolobium niveun)........................ oo....... Twining......... 10-11 months...... Yokohama bean (ltizolobium hassjoo).................. Good....... Tu ning......... 10-11 months..... Sword bean (Canavalia ensitormis)......................... ood....... Bushy........... 11-12 '1 months... Small...... Ielicate.......... Slight Medlium.... Vigorous.f....... Severe Small...... Ielicate.......... light Large...... Very vigorous..... Severe Medium....Vigorous.......... None Mediium.... Vigor u.......... artial Mlediuml.... \'gorous......... 'artial Medium.... Lacked vig. r....., Leaf spot" Large...... Very vigorou..... Slight Large...... \Vigorus........ I'artial largt..... Vig\' rous.......... IPartial Large...... Vigoroul........... Iartial large..... \'igorous..........Stalk borer'4 Reported by Mr. J. A. Stevenson, Pathologist, to be caused by Cercospora sp. * These varieties have continued to grow from the old roots until the present tine, which is about fifteen months since they were planted, but with a decline in vigor. This variety has now been growing for fifteen months and with all its original vigor. ~ Identified by T. H. Jones, Entomologist, as Balloria,istip/enni. Several leaf-eatinginsects were also identified, of which Naroleia indicnat was most important, Fertilizer experiments.-The purpose of the fertilizer experiments at this station is to determine what are the requirements for cane growing on the classes of soil found here, the best form in which the fertilizing elellments (cin be alpplied, andl tile best manner and time of making the applications. As stated alove, arrangements are being made to carry on similar experiments in other parts of the Island to determine the soil requirements of those places. It is proposed to give tile plots identical treatment each succeeding year, in order to determine what treatment will maintain sufficient fertility in the soil for profitable cane growing. The experiment on lowland soil, reported in the last annual report was replanted and will not be ready to cut until the coming harvest. The experiment on hill land was cut and tile weight of the cane trecorded. The following table (Talle V) shows the fertilizer ingredients used, the amount per acre applied to each plot, the yield of cane per acre from each, the amount of fertilizer applied, and its approximate cost. The elements were applied in tlhe form of sulfate of ammonia, double superphosphlate, and sulfate of potash. Table V.-Comparative yields of cane. Fertilizer tests. Forinila I i 1l1ot- -a e (11;( 1; l fertilliz.r (ost per No. i t Ir(re! er fare acre I'omlsind~s pi 'er are r I' losphorI( aclid, (0 Nitrogen. 120................ 0.90 735 $22.20 2 ' lios. 'l iO. 12, N. 1 12. -, 12 i ot; sh. 120........................ 2 5 1.110 31.50:{ I' os ac id. f20 N. 120...................... 2.75 19.( ) 28.20 4 Phos. act l. 1'0 N, 6(0......................... 6) 6 18.45 5 Not fertilized...........................5 5 N~fte t'ortilizei '....................................... I........ 6 Not fe. illiizel......................................... 0 7 Phos. acid, 60 N, 120;, t........................... 20 10 8 5 ' 50 8 Phos. aci. c. ( * N '. () I.. 60.......................... 22.05 ) 55 15.75 9 N. 60 t l'o t., 0........................................... 13.20 i 420 13.05 10 Phos. acid, (0 N,..................................... 1!9.20 o 135 12.45 Average yield of cane from the unfertilized plots, 8.17 tons per acre. Average yield of all fertilized plots, 21.22 tons per acre. Average yield of comp1Ilete fertili;cr plots, 22.46 tons l:er acre. The beneficial effect from the use of fertilizers and the profit resulting from their use on this soil is very apparent in this experiment. The average yield of cane from all fertilized plots was 21.22 tons per acre while that from the unfertilized plots was 8.17 tons per acre, showing a gain of 13.05 tons cane per acre. The average yield from the plots to which complete fertilizer was applied, i. e., that having all three of the elements, nitrogen, phosphoric acid and potash, was 22.46 tons per acre, or a gain of 14.29 tons per acre over the unfertilized plots. The plot giving the highest yield was No. 4, 32 to which had been applied 120 pounds phosphoric acid, 60 pounds nitrogen, and 60 pounds potash. This plot gave 26.60 tons cane per acre,-a gain of 18.43 tonG cane per acre over the average of the plots without fertilizer, or over three times as mnuel. Trle results obtained are in agreement with those obtained in the two years previO~lS. IIn each year tive 1)lot with high phosphoric acid has giv~en the best returns. The effect. from the use of potash hias been les than that of either of the other elements. The effect from the use of nitrogen has been secondary to that of phosphorie aeidl onl this soil in all three years dlurinig which the experiments have been c-onducted. 'If similar results are b)orne out in Succeeding years it will ineaii a cheaper fertilizer for this soil, as nitrogen is the most expensiVe element of thie flbree essentialis o)f comilmercial lemi ilizer's. Tb' soil on which this experiment is condlucted is a,, light clay. with fairly good drainage. Linic.-The exlperimnent onl the valuie of a large application of lime was (Containued as before, to test the length of time over which the beneficial effect will continue. This exlperiment is onl lowland clay loam. soil. Four tons of lime were -appliedl to one 1)lot of one-hialf acre, in the year 1912 only, while anot~her plot of equtal size was left without lime. The yields of eane obtained eahvear aire shown in the following table: Table VI.-Experiment on the use of lime in a large application. I'ot Treat nien t, Tottsetinf-pere are 'I'muis cnefi e r acre fTuns a icp(rtacre Lime tier avro 1913 ot 91. 91 I 1 itns.15.82 28.51 21.62 2 None 0.35187.3 9.52 (,ati from the use of lfine.. 1.A8 1.1.78 12.1(0 REPORT OF THE PATHOLOGIST. I B% bit N A. STtEvt:NSGN.] INTRODUCTION. At the beginning of the fiscal year the then pathologist, Mr. John' R. Johnston, was -authorized b~y the Board of Commissioners of Agriculture to proceed to Washington in order to complete the preparation of relports upon the entomoglenous.8 and cane fun~gi Of Por-to Rico, the necessary facilities in the way of literature and specimens for comparison not being available here. It was also desired to consult 33 with officials of the United States Department of Agriculture in collaboration with whom the work on cane fungi was being carried on. During this period the assistant pathologist was engaged in the preparation of Mctarrhiziumw splore m1aterial, tlhe details 'If whllich will be given later, together with the regular routine of the laboratory, preparations of cultures, care of herbarium, etc. In addition much wap accomplished toward placing the library of the station in proper condition for use. On Septenbler first MIr. Johnston resigned and Nwas succeeded by the former assistant pathologist. From that time attention has been centered largely upon the fungus problesll of the citrus industry, with especial attention to the life history and Ineans of control of the so-called "citrus sealb' or "lemon scab" which has become a most threatening eneiimy of the grapefruit. At the proper time cooperative spraying experiments were inaugurated and followed through the season. In addition much time has been spent in the editing of the various station publications, care of the library, and discharge ofl duties as acting director in the absence of the director. PROGRESS ON DEPARTMENTAL PROJECTS. WORK WITl TIIE GREEN MITSCARDINE. Work at this sta'tion has been carried on for a number of years with tile green mllsear(dinet ( M'larrhl iziam (i).isopliO(i) al fungus widely distributed throughout the world, which has been found attacking and destroying a number of harmful insects. This fungus was introduced in 1911 from Hawaii as the "Hawaiian beetle fungus" and experiments have been conducted with it since in order to ascertain as to whether or not it would prove of value in the control of white grubs, serious pests of sugar cane in parts of Porto Rico. The work has been carried on both in experimental cages at the laboratory, and on a field scale near Yauco. Results in the breeding cages were fairly successful upon the larva of the species of "caculo" or May-beetles (Lachnosterna). At the south-coast laboratory at Ensenada the fungus is present to such an extent as to seriously interfere at times with the progress of studies on the life histories of the various beetles attacking cane. On the other hand no such success has attended the field trials which have been conducted in the neighborhood of Yauco. It is planned, however, to continue the work at least another year, and to include a locality on the north 34 coast where the mnore humiid conditions may give more favorable results. To produce the spores of this fungus in large quantities the Trinidad method of large cabinets with facilities for steami sterilization is used. The station apparatus consists of two large. cabinets, which suffice to 1)roduee fifty pounds of dry spore mnaterial together with one hundred pounds of residue. These, cabinets are sterilizel lby steami fromt a 5 11. P. upright. lboiler. Each cab~inet contains a nuinbcr of shelves on which the rice, serving as food for the fungus, is spread. The (loors are then bolted on and -steam~ under prcssuire applied until the rice is cookedl and completely steriliz.ed. With an atomizer spores are sprayed over eaclh layer of rne mnedia., and thle cabinets left until a thick layer of the typical green spores form.i over the rice. Thien by ajp~)ling a cheap) grade of flour the brushing off of the spolrcs is easily aevoniplislhed and aI desirable (dilutionl of the( material secuired. Tpli s mixtirme is tihen applied inl grub-infected fields with any of thie var-ious ty sof (lusting machelines. 11wI reVmiaining rice residlue can likewise be 115(cd andl is aplplied by hand., a Small portion being scattered aroundl each stool of canec. It now seemis fairly certain that the, greeni luscardline existed on the Isla-id to a limited (extent lpreviolus to its introdluction from Hawaii. rrhe fact. that it (loes exist here anld has niot become epidemlic would seciu to militate -against the( success of lpresenlt exp~erimients, esp)ecially inl the light of results obtained to date. CITRUIS DISEASF&S..Much of thle timne axvailable ha;s lbecim sqwnet in a gener-al sum rVely of the citrus grov%,es of the Island. While notes hv been t1akt"u on the(, occurrence of all (lis-eases fouind, special1 at tent ion hals been given to citrus scab. andl suich exporimnents as have leceu ()011d(lfi-td h~ave had as their ainn the control of thtis (liseas-e. (Consi(I-ringr thle general. lack of -attention to thie siilmjetl of fungus (disetIlSeS "givnc by the growers, the citrus groves as a whole have been eamparatively free of serious trouble in the past years. During recent seasons, due to the combined causes of unfavorable climatic conditions, the greatly enlarged plantings and the accumulation of the- diseases present through lack of preventative steps, the losses attribuitable to fungi have steadily increased and now take a total that is heavily felt. The most serious of these are discussed in more detail below. Citrus scab.-This disease sometimes known as "verrucose" or "lemon scab" has been present in Porto Rico on sour orange and 35 lemon for maany years. It was generally present on these varieties in the nurseries, but no steps were taken against it since the grapefruit and sweet orange were practically immune. In the past few seasons the grapefruit has lost this immunity and is now attacked in certain districts to such an extent that it is not at all uncommon for entire crops to be rendered unmarketable or at least so disfigured as to be salable only in the lowest grades. The orange fortunately still maintains its immunity. The disease is caused by an organism, the exact position of which is uncertain although referred to by most writers as Cladosporium citri. More exact studies of its nature are necessary, as well as extensive cross innoculation tests with plants found in and about the citrus groves. If it is found that the disease can live on other plants than citrus, present control measures must be modified to meet the situation. All such innoculations to date have given negative results. Various other points in the life-history are obscure and will be made the subject of investigation. Control measures advocated in previous publications on the subject have for the most part consisted of general statements of the advisability of removing sour orange or other susceptible varieties and the pruning out of infected leaves and fruits, supplemented by spraying. In the absence of more specific directions most of the growers have failed in their attempts to control the disease or have come to grief with improperly handled spray. For this reason cooperative experiments were initiated looking to the control of scab, and in addition, the spraying operations of other growers have been followed. A report on this work together with a more detailed (Icscription of the disease with recommendations for control is to be given in another publication. Foot-rot or knal-di-gomma. —This is a disease whlich seelms to le on the wane. Not many years ago it was the only disease known to the growers and caused much damage, entire blocks of trees being lost in certain localities. As has been noted by all writers on the subject, it is most prevalent on lemon roots in low or poorly drained land. The lemon was formerly very largely used as a stock for both orange and grapefruit, and the present freedom from the trouble may be in part attributed to the practical discontinuance of it for this purpose, or at least the discontinuance of its use on improper land. A second reason occurs in the largely increased knowledge of the planters themselves, with regard to the relation of cultivation and proper drainage to control of the disease. 36 A fungus (Fusarilum sp.) has been found present in typical footrot. ases, but no attempits have bee1n made to rove or disl)rove its parasitism. Proper drainage and tile use of stocks otiler than lemon given an easy solution of the problem, and foot-rot should become only a lmtemory of the pioneer days of tie industry. Fruit rots.-Considerable difficulty has been experienced during the season just past with fruit rots, the loss at times, particularly at the beginning of the shipping season, running as high as 50 per cent. Rots may be divided into two main classes, those where infection takes place at the time of picking or later, and those where infection occurs while the fruit is still on the trees. In the first class are included the blue and green molds (Penicillitlm spp.) and to a le ss extenlt otlier saplroplhytic fnllgi (lh'iop,. nigricans, Aspergillus niger, etc.). These forms are only able to attack the fruit after it has ripened and a bruise, cut or other injury afforded a place of entry. The general relation of this type of decay to care in picking, packing and shipping is quite generally understood by the growers and it is now under fair control. For more detailed information along this line, the grower is referred to Bulletin 7 of this station, "The Handling of Porto Rican Oranges, Grapefruit and Pineapples," by C. W. Mann, of the United States Department of Agriculture. The second class includes those fungi which are able to attack sound fruit while it is still on the trees. In Porto Rico the stem end rot due to Diplodia natalensis is the common form. The general nature of this fungus, its method of attack and control measures have already been discussed by other writers in Porto Rico.1 Phomopsis citri, the principal cause of stem-end rot in Florida has not yet been found on the Island. In addition to Diplodia other fruit rotting fungi of less importance occur. First among these is the anthracnose fungus which is held responsible for the dropping of young fruit, as well as the spotting (anthracnose) and tear staining of larger fruits. This fungus is universal throughout the Island causing a dieback of the twigs and spotting of the leaves in addition to the damage to the fruit. Most growers fail to realize the necessity of careful and continued pruning and removal of all dead wood; this material being the source of all infection of the fruit. Spraying has not been recommended for the control of this disease but rather proper sanitary measuresFawcett. G. L. "The Rot of Citrus Fruit." Porto Rico Progress, D)ecemlxer 23, 1914. Mann, C. W. Loc. cit. 37 the pruning and burning of diseased tissue with disinfection of the tools used, by means of a formalin or mercuric bichloride solution. Blossom-end rot of oranges.-In the orange groves trouble has been experienced not only with the stem-end rot and anthracnose, but with a so-called blossom-end rot. The greatest loss from this cause occurs in September and October, that is to say, at the beginning of the shipping season, after which the fruit is comparatively free of the trouble. The signs of the disease are very characteristic, consisting externally of an abnormal bright orange-colored area of varying size about the blossom end. Porto Rican oranges when healthy never assume such bright colors, making it most easy to pick out diseased fruits. An affected fruit drops when the bright coloration has spread over a major portion of the surface, often even before the coloring has progressed to any extent. Internally there is at first no sign of disease beyond a slight browning of the blossom scar and the tissue immediately beneath. Finally a brown rotting occurs, spreading first along the central axis, involving the seeds and rag, and last of all the juice sacs in a soft brown rot. On the surface this appears as a circular area spreading from the blossom end, medium brown in color, soft and slightly sunken, which finally involves the entire fruit. Cultures were obtained by sterilizing fruits externally in mercuric bichloride solution, and then placing bits of infected tissue from beneath the surface in nutrient media. A very characteristic fungus growth was obtained in all cases, a species of Fusarium which, on the culture plates, produced bright carmine-colored colonies. It is proposed to continue studies with this fungus, to ascertain its life history and to discover means of control For the present it is advised that all drops and affected fruits culled out in the packing house be buried and that the sanitary measures before mentioned be carried out. Black rot of oranges.-In the course of the work with the Fusarium blossom-end rot, another type of rot with very similar external appearances was encountered several times. This is the black-rot or navel rot of the orange, a disease reported as prevalent in California and to a lesser extent in Florida. It was also found as the cause of a rot of oranges from Spain, seized in quarantine. In Porto Rico it has at no time been of any great importance, there being a hundred or more cases of the Fusarium red-rot where there is one of the black rot. The cause of the rot is a fungus known technically as Alternaria citri. Externally the disease is not distinguishable from the other type, but there is a marked internal difference. In the black38 rot type the rotted area is of a decided black color extending well into the pulp around the blossom end, while, with the other type, the rotted region is either colorless or of a pinkish tinge, which becomes red when exposed to the air. This latter type is also more confined to the rag. The measures recommended in the previous case will likewise apply here, and further studies along this line will be made in connection with the red rot, the two forms being probably entirely similar in their actions. Citrus canker.-As soon as the serious nature of this disease and the possibility of its entry into Porto Rico was realized a press notice was issued as a warning to the growers. A quarantine measure was provided by the Board of Agriculture in December prohibiting the entry of all citrus material from the Gulf States. The regulation was broadened in April to include all living plant material from the citrus-producing States, and citrus material from all parts of the United States. Great care has been taken to enforce this ruling, various packages of plants having been turned back or destroyed. Since the disease existed in Florida and other of the Gulf States for some time before it was discovered and announcement of it made, there was the possibility that during that time it might have reached the Island, on shipments of citrus or other nursery stock sent from infected nurseries. Since the disease is bacterial in its nature and very resistant to known methods of treatment, ordinary quarantine Iprelaltions such as ftnmigation as practiee( against insec('ts defoli:ation, etc., would not have availed to prevent its entry. Consequently the necessity of inspecting all shipments of plants to l'orto Rico, from the infected States for as far back as the disease was known to have been present. The carrying out of this task was made possible by securing a list of all such shipments from the quarantine records. Then, as rapidly as possible, a careful search for canker was made on all.plants included in these shipments in the various groves and gardens where they had been planted. This work has, to date, yielded no traces of canker, though certain of the plants have been examined several times. It is felt that at the present time Porto Rico is free of canker. Whether or not this freedom can be maintained depends largely upon the attitude of the growers themselves. CANE DISEASES. Work with cane diseases during the year has been limited to observations upon the various types of root-disease and field studies of Cytospora sacchari. 39 Cytospora sacchari.-This is a ccmparatively new disease of cane, for which no common name has as yet been proposed. It was first discovered in 1912 by the former pathologist, on foreign varieties of cane at Rio Piedras, and ihere seems no reasonable doubt but that it was introduced with some one of these varieties, large numbers of which were brought in from all parts of the world until the estab'lishment of the plant quarantine. The only other known report of its occurrence outside of Porto Rico is from British India where it was described as a very unimportant disease of the stalk and leaf isheaths. To date it has been found in Porto Rico on the following cane varieties. At Rio Piedras on Barbados No. 7169, 6385, 175X, 8660, 7245, 3696, 3859. Demerara No 109. Near Carolina a well developed case was found in Rayada cane, though still confined to a small area, and in the eastern end of the Island, B 1355, B 3922, D 117, G C 759, and G C 47 were attacked. The symptoms of the disease are well marked. Young shoots are killed outright, others checked in their growth, and at least the lower leaves killed. The leaf sheaths are bound firmly together about the stalk by the mycelium of the fungus, the leaf blades drooping in!a characteristic manner. The exposed portions of the leaf sheaths are a dull dark red in color and are covered in profusion with the fruiting bodies of the fungus, the long sharp-pointed necks of which project beyond the surface sufficiently to be readily seen and give a rough sensation when the hand is rubbed over the area. During wet,weather a minute yellowish globule of conidia can be seen with a hand lens exuding from the mouth of each pycnidium or fruiting body. In addition to killing outright young shoots, the older stalks are invaded with a resulting dry-rot which renders them worthless for sugar production. Because of the fact that this fungus, of no importance in other parts of the world, has been able to attack a number of varieties of cane here, and do some damage, fears have been entertained that it would become epidemic. The situation is being closely watched, and an attempt will be made to eradicate it completely in those localities where it has appeared. Root-disease.-There have been a number of complaints of loss due to root-disease, a trouble caused by a number of different organisms, but all yielding to the same treatment. The native white 40 cane has been found particularly subject to this trouble, and the planting of other more resistent varieties has been recommended, together with such corrective measures as improved cultivation, liming, proper drainage, or irrigation, and sanitary precautions. Observations have been made upon the experimental plot at Canovanas where a number of varieties were planted in land badly inl'fctd with root disease, but no conclusive results have\ as yet l)een ol)tailled. Other diseases of cane have not been prominent during the year. Cane fun)gi bulletin.-There is in manuscript form aiwaiting publication a paper on the "Cane Fungi of Porto Rico" containing descriptions of some sixty fungi which either directly cause disease in sugar cane or are followers or helpers of those that do. The collection of these fungi, and the preparation of notes and descriptions was carried on by Mr. Johnston and his assistants through a number of years while the experiment station was conducted under the auspices of the Sugar Producers' Association. In addition to the descriptions of tile various fungi, notes on disease control are given. MINOR DISEASES AND NOTES. Mold of cigars.-One of the tobacco companies reported trouble with mold on cigars, appearing a few days after manufacture and necessitating extra work for its removal. In the samples sent for examination the mold appeared as a thin white coating, for the most part limited to the head of the cigar. From such cigars a number of fungi were isolated, Aspergillus flavus, Aspergillus sp. (an unnamed blue-green form), Cladosporium hcrbarum, Penicillium sp. and Fusarium sp. These are all common saprophytic forms, and it was immediately concluded that the key to the situation lay in the proper care of the gum tragacanth used in fastening the wrapper, since a study of a similar trouble by the United States Department of Agriculture,' with similar fungi involved, led to such a.conclusion. Consequently the boric acid solution for making up the past was recommended for trial and has proved successful in controlling the mold. Rot of prickly pear.-Specimens of spineless prickly pear affected with a soft rot were sent in from the south coast. In freshly attacked regions the affected areas were brownish with a water soaked appearance, clearly separated from normal tissue. In the older rotted portions, there had been an exudation of gum which had hardened 'The Molds of Cigars and Their Prevention. Bulletin of the United States Department of Agriculture, No. 109. 1914. 41 in black or gray globules, giving a rather curious shaggy appearance. Pycnidia were present in great numbers showing as black points on a dirty white to light tan background. The rot appeared to start at the base of each slab and progress upwards until the slab was completely involved. The fungus is apparently referrible to Diplodia opuntiae Sacc. Leaf-spot of water melon.-The leaf spot (Cercospora citrullina) of water melon has been noted as occurring in various localities near San Juan; at times causing some damage through the early death of the vines and premature ripening of the fruit. The spots are more or less circular, two to four milimeters in diameter, gray at the center with a dark brown margin. Bordeaux mixture has been recommended as a remedy for this disease, applied as soon as there is any sign of the disease on the leaves and continued at intervals of a week to ten days. Leaf-spot of cow peas.-In the experimental plot at the station a plot of cow peas was so severely attacked as to be practically defoliated by a leaf spot fungus, probably referrible to ('rcospora Ecignae. No other reports of damage by this disease have been received though cow peas are frequently grown as cover crops in citrus groves. It is possible that a particularly susceptible variety was being grown at the station. HERBARIUM AND COLLECTIONS. Satisfactory progress has been made with the herbarium and the general collection of fungi. The herbarium serves a very useful purpose in facilitating determinations of host plants both for this department and for the entomologist and his assistants. In addition, some outside determinations have been made. For the original determinations of the flowering plants we are indebted to the New York Botanical Garden with which institution we are still co-operating to the extent that in exchange for a set of all specimens collected the correct scientific names are supplied. PUBLICATIONS. The principal publication of the year was Bulletin No. 10, "The Entomogenous Fungi of Porto Rico," by J. R. Johnston, former pathologist, a summary of which follows: "For a number of years studies have been carried on with the various fungi attacking insects, cultures have been made, innoculations carried out, and the structures and nature of the fungi them42 selves worked out. Notes of occurrence, insects attacked and descriptions are given of the following species: "1. The Aphis Fungus (Acrostalagmus albus) attacks plant lice on sugar-cane, okra, and other plants, forming a yellowish covering over the host insects. "2. The Brown Fungus (Aegerita Wcbberi), a well-known form which in Porto Rico, attacks the white fly of the guava in certain limited localities. "3. The Aschersonia group.-Three species are named and a fourth with perfect stage occurring on white fly on Bignonia unguis described technically. "The Red Fungus of the White Fly (Aschersonia alcyrodis) coinmon on the guava white fly. "The Top-shaped Aschersonia (Aschersonia turbinata), recorded on a variety of insects. It is the only one of the group found so far attacking citrus insects. "The Lemon-yellow Fungus (Aschcrsonia favto-citri, ) on the guava white fly. "4. The Yellow-green Fungus of Mealy Bug (Aspcrgillus flalics) is exceedingly commion on the sugar-cane mealy-bug which occ(urs in colonies beneath the leaf-sheaths. A study of various forms shows them all to be referrible to the one species. "5. The Green Fungus of the Grass Worm (Botrytis rileyi). Not common. "6. The Shield-scale Fungus (Cephalosporium lecanii), is very common on the hemispheric scale, a serious pest of citrus trees and many other economic and ornamental plants. The fungus at times completely checks the scale. "7. Enmpsa fresenii, is reported as attacking mealy-bugs of cane. Not common. "8. The Spider Fungus (Gibellula arachnophila) an interesting form attacking spiders on guava. "9. The Moth-borer Fungus (Cordyceps barberi), found in the Isaria or imperfect stage only. "10. The Green Muscardine Fungus (Metarrhizium anisopliae) is thought to occur naturally although it has been introduced from Hawaii. Experiments have been conducted with it, as well as studies made of the fungus itself. "11. The fungi commonly attacking the scales of citrus trees are described. The Black fungus (Myriangium duriaei), White-headed fungus (Ophionectria coccicola), Red-headed fungus (Sphaerostilbe coccophila), and the Cinnamon fungus (Verticillium heterocladum). 43 The first three mentioned occur very abundantly in all groves and are of very great value to the growers of citrus fruits. Circular 4 —Warning to Citrus Grolwers.-A general description of the citrus canker disease of the Gulf States and the danger attending its possil)e introduction into Porto Rico, together with the quarantine regulation of the Board of Commissioners of Agriculture barring the entry of citrus material fron Florida and the Gulf States. Press notices.-In addition to the above, various press notices have been prepared and published in the newspapers of the Island, dealing with various phases of the departmental work. PROJECTS. 1. The Green Muscardine (Metarrhizium anisopliac.) The preparation of spore material for experiments in control on a field scale of white grubs. In co-operation with the entomologist. 2. Citrus scab.-(a) Laboratory studies of the life history, innoculation tests with weeds and plants occurring in citrus groves. (b) Field studies of method of spread, relation of climatical conditions etc. (c) Experiments in control. In co-operation with various growers. 3. Fruit rots of citrus.-A study of the various fungi involved, their method of attack, nature of the rots, and methods of control. 4. Cytospora saccha.ri.-Laboratory and field studies of the life history, varieties attacked and means of control. 5. Root disease of cane.-Study of the fungi involved and control measures and in particular the question of immune varieties. 6. Disease survey of the Island.-The collection of specimens and keeping 'of notes upon occurrence of all plant diseases, their virulence, the plants attacked, localities where found, etc. To enable the plant-quarantine branch to determine what diseases do not occur here. Under this heading may be grouped the study of minor diseases of citrus, cane and other economic crops. 7. Herbarium.-Collection of plants of the Island of all classes, aiming towards a complete representation of the flora of Porto Rico. 44 REPORT OF THE SOUTH COAST LABORATORY. [By EUGENE G. SMYTIH. INTRODUCTION. The main line of investigation carried on at the south-coast laboratory at Santa Rita has been in making a detailed study of the life histories of the white grubs which attack sugar-cane. Most of this work is carried on in the laboratory, but field observations have been made to confirm and supplement the results obtained in the laboratory. During the cane-grinding season. stealmers arrive daily, 'exc'ept Sunday and sometimes Monday, at Guainica Cntrale, bringing sane from La Romiiana, Santo Domingo. The leaves of the calne in Santo Domingo are eaten by the caterpillar of a butterfly, Calisto archebates 5Men., and the cane llas suffered very severely from injlry by these insects during previous years. To prevent the introduction of this or any other sugar-cane insect l)est froml S4anto )Dominlgo into Porto Rico, the holds of the boats containing the cane are fumigated by the burning of sulphur. This destroys all insectr. The fumigation is done by the crew or the ship when it leaves La Romana, but to make sure that the fumigation hlas been effective and all insects destroyed, each boatload of cane must be inspected by a competent entomologist. All boats arriving during the pbast season have been inspected, either by Mr. Wolcott, or by the writer in person. As a large number of passengers caine to the Island on tile Santo Domingo boats during the past season, inspection of thelir baggage was necessary whenever it contained fruit or plants. All fruits or plants suspected of being infested w ith insects were destroyed, or brought to Santa Rita to breed out and determnine the insect. Scale insects on oranges, and on palms, and white flies (Alcyrodcs) were intercepted and destroyed. To assist in attending to the life-history work with white grubs in the laboratory, the board secured the services of Mr. Wm. C. Hanson, Jr., for the period during which the cane boats would be running. It is largely due to the assistance of Mr. Hanson that the breeding work was continued without interruption. Mr. Hanson began work on January 18, 1915, and resigned on June 20. The writer made two visits to the Experiment Station in Rio Piedras for the purpose of using the photographic equipment to make illustrations of the white grubs, the adult beetles and their parasites for a complete bulletin on the white grubs of Porto Rico, 45 soon to be issued. During the writer's absence from the south-coast laboratory, the inspection of the cane boats and charge of the breeding experiments in the laboratory was taken over by Mr. George N. Wolcott, entomologist of the Board of Agriculture. THE WHITE GRUBS. Eight species of beetles of the family Scarrabacldae are known to injure cane in Porto Rico, or are found in the oane fields and may be injurious. They are Lachinosterna grande, L. media, L. (pc(uefa, Ligyrus tumulosuis, Strategus titasnus, Strategus quadrifoveats, Dyscinetus trachypygus and D. barbatus. At least four of these-thel largest species of Lachnosterna, the Ligyrus and both the Strategus are known to directly injure cane. Specific injury by any of the other four would result only in case of severe outbreak of the insect, or perhaps of drought or other adverse condition coupled with unusual abundance. In studying these species, it was of primary importance to determine how long each species spends in the ground as egg, grub and pupa before emerging as a beetle and also what factors of temperature and moisture, or change of conditions ~and of food, influence their behavior in the earlier stages. The object of establishing these facts is to have a solid foundation upon which to base any attempt at their control by the artificial changing of these conditions. 46 Life-History Summaries of the White Grubs of Porto Rico. Species Lachnosterna grande.............. Lachnosterna media............... Lachnosterna pequefta........... Strategus titanus................. Strategus quadrifovatus.......... Ligyrus tumulosus................ Dyscinetus trachypygus.......... Dyscinetus barbatus.............. Egg to Egg period st instar 2d instar Adult Av. Av Max. n. I iA. Ar. Max. in A. Ma Mil. (9) (1089) (178) (() 341 days 14 days 22 11i 37 days 62 17 d1 ays i 00 2 (1) (508) (60) (76) 324 days 13 days 21 11 i days 35 13 31 days 39 23 *1 (146) (30) (11)s year 11 days 10 12 30(lays 39 21 t5 days 57 12 (13) (145) (68) (67 338 days 17 days 21 15 39 days 76 22 60 days 93 30 (2) (4)(4)(5) 430 days 20 days........... days............ (23) (145) (51) (3i) 77 days 13 days........ 13 days.......... 15 da.......... (13) (125) (46) 3:1) 101 days 12 days 18 10 22 days 38 17 15 days 23 13 (3) (28) (8) (3) 144 days 13 days....... 19 days 35 13 28 days 36 12 i~~~~~~~~~~~61 3d instar Av. Max.i Ml. (7) 155 days' 172 151 (12) 178 days, 220 138 (2) 1941 days............ (40) 185 days 245 111 (2) 27. days...... (28) 27 days i............ (II) i 44 days 50.35 (3) 59( days 74 44 Pupal period Av. Max. Min. (20) 21 days. 21 20 (1) 22 days............ (15) 23 days (2) 27 days (12) 14 (ays (5) 13 days (4) 15 days 24 16 18 12 13 * Indicates total life cycle. Figures in () indicate number of grubs, eggs or pupa averaged. It was to obtain this information that much of the writer's work during the past year was confined to the insectary. Not a few, but dozens or even hundreds of each species have been observed under various conditions in confinement. At no time during the year have there been less than 300 grubs and eggs under observation in the insectary at this laboratory and often there have been over 500. The complete life histories of all the eight species have been worked out from egg to adult. In the accompanying table the average time in days and the maximum and minimum periods for each stages of the beetles are shown. In addition to the study of the living grubs, there have been preserved for future study very complete biologic series of each species, including every stage from egg to adult. Many of these have been photographed in such a way as to show the characters which distinguish them. One of the most interesting discoveries of the year is that two distinct varieties of L. grande and L. lltdia occur on the Island. The variety of L. grande found on the north side is larger than that found near Guanica and is more widely distributed, having been taken at Aguirre, Rio Piedras and Manati. The L. grande of the * outh side is more than 100 times as abundant as L. media at Santa Rita, but the northern varieties appear to be of about equal abundance. Flamboyant (Poinciana rcgia), casuarina (Casularina cqilisitifolia), and almendro (Terminalia catappa), are favorite food plants of the adults of both the northern varieties; Acalypha sp. and Citrus spp. are acceptable only to L. media. and the leaves of the cocoantit pc in art eaten only by the beetles of L. grande. The adults of L. media appear at Santa Rita from March to June only, but those of L. grande, although most abundant during the spring, have a second period of abundance during the fall. As will be noted from the life-history summary, the life cycle of both species requires a year for completion. (The complete life cycle is obtained by adding the "egg to adult period" to the period of about a month after the beetle first emerges from the pupa before it mates and begins depositing eggs.) Thus the fall abundance of L. grande beetles does not mean that these are descended from the beetles that appeared in the spring, but rather that there are two overlapping generations, the beetles of one appearing at a time when the other consists of half-grown grubs. In some of the low-lying cane fields adjoining the Rio Loco at Santa Rita, the adults of L. pequefia appeared the latter part of July, 1914, and disappeared from the fields in September. For that period 48 the beetles were quite as abundant as these of L. media had been in April and May. Many adults were collected, most of which were feeding on "bledo" (Amaranthus spp.) among the cane. A few were feeding on "malojillo," or Para grass (Panicun barbinode), but none on cane. The white grubs of L. pequeia are v ery small and must be present in great numbers to cause any appreciable injury to cane roots. Strategus titanuts is second only to Lachnlosterata grande in point of injury, for its grubs have been frequently found boring in the living tissue at the base of very recently cut cane stools. The adults of Strategus quadrifoveatus are very readily distdinguished fronm S. 'titanus by the much greater size, shining elytra and the single toothed horn of the male. Two cases of its attacking cane, one at Fortuna and one at Santa Rita were reported last year, but no injury has since been observed. Grubs of this species are not known to injure cane. Considerable difficulty has been experienced in the laboratory in an attempt to rear the grubs from cane stubble, and after the first larval instar they refuse to eat cane. Rotten wood seems the preferred food of the older grubs, which often eat off the bottom of fence posts just below the surface of the ground. The life cycle of this species appears from the records to require considerably over a year for completion, although that of S. titanus occupies only a year. Grubs of Ligyrus tumulosus are found in cane stools some days or weeks after the cane has been cut, when the stumps are beginning to dry out or decay, but only in exceptional instances injuring living cane. In Tabl6n No. 13, Hacienda Santa Rita, the see(l cane was replanted three times before a satisfactory stand was obtained, partly because of the injury by the weevils of Diaprepes spenglcri, but mostly cause of the injury caused by the third instar grubs of Ligyrus. The total life cycle of Ligyrus occupies about 110 days, which would allow three generations in a year, but the beetles do not have any definite generations and may be found at any tims of year. The two species of Discincetus also have a short life cycle which would allow at least two generations a year. D. barbatus is the less common species, scarcely more than a dozen having,been seen at Santa Rita during the past year. The adults of D. trachypygus are often found under electric lights, sometimes in considerable numbers. On July 1, 1914, at Santa Rita, they were most unusually abundant, although on preceeding and following nights, only a few were to 49 be seen. The grubs of Dyscinetus feed only on buried trash, old cane stubble and cachaza, never attacking the roots of live cane or other plants. REPORT OF THE TOBACCO INS1CT INVESTIGATIONS.' [By G. B. MERRILL. On September 10, 1914, the writer was detailed to carry on the tobacco insect investigations that were begun by Mr. S. S. Crossman, but as the notes made by Mr. Crossman were not available, it was necessary to start at the beginning of the various problems. Observations were made of the modes of cultivating the tobacco, the methods of combatting the various insects of economic importance, and life history work on those of most economic importance was begun. Many thanks are due to.the officers and employers of the Porto Rican Leaf Tobacco Company and the various owners of small plantations for their hearty assistance rendered wherever possible. The work in the laboratory has been in ascertaining the life histories of the changa or mole cricket, Scapteriscuts didactylus Lati.: the flea beetles, Epitrix fuscata J. Duval and Epitrix parvula Fab.; the wireworms and the hornworms, Phlegothontius sexta Joh. The life histories of none of these pests have as yet been completely worked out. The main depredators of the tobacco plant are the flea beetles, of which there are two species, the black, Eptrix fuscata and the brown, E. parvula. The former is by far the greater pest owing to its being abundant during the whole season, while the latter varies greatly in abundance at different times. Next in order of importance is the "changa" which does most of its injury in the seed beds or on newly set transplants. Others of lesser importance are the hornworm, the cutworms, the wireworms, various bugs and a leaf iminer. Slugs or "lapas" do considerable damage to newly set transplants. Adults of Diaprepes spengleri have been noted feeding on the leaves. In the seed beds, the changa is the greatest pest to tobacco. When strictly attended to, it is fairly well controlled by the Paris green and flour mixture consisting of three parts of Paris green and ninety-seven parts of an inferior grade of common white flour.* InveFtigations carried on at the Aibonito sublaboratory. * Circular 6, Insular Experiment Station. "The Contro' of the Changa." 50 This may be spread on the burrows cr it may be broadcasted en the seed bed. but not to such an extent that it will injure the young plants. The two species of flea beetles and the cutwornms do consilderalle damage at times to the seed beds and especially prior to transplanting. As an insecticide for these, dry powdered arsenate of lead, of the "diplumbic" form and made especially for tobacco work is mixed with fine, very dry wood ashes such as come from the bakeries. It is used at varying strengths according to experience, but to prevent injury from burning the mixture should contain not more than fifty per cent of the poison. During the past season, much injury was done to the leaves by the arsenate, probably in water soluble form. During the coming season it is hoped that experiments will determine definitely just what is the cause. Experience has shown that it is best to apply the powder during that part of the day when there is no dew upon the leaves. In the fields which are under cloth and where the plants have just been set in tile ground, considerable injury is done to the young plants for the first week or so by the changa, which is general in distribution, and by the wireworms which are local. The slugs also are injurious at this time, especially in the vtga lands. As the plants grow older, much less damage is caused by these pests. The flea beetles are a constant menace and on the older plants require much expense and labor to hold in check. Dry powdered arsenate of lead and wood ashes can be applied with the blow-gun until the plants and leaves become so large that the gun tears the leaves. The beetles must then be collected by hand. For this purpose a small ball of soft cloth is made and tallow (cebo de flande) is spread upon the lower surface, and with this the workers go about from leaf to leaf catching the adult beetles. No injury to the tobacco has been noted with the use of tallow. The hornworms do some damage but they are easily controlled when small by the arsenate of lead and wood ashes mixture, and by hand picking when they become larger. The hornworm is also kept in control by its natural enemies. Its eggs are parasitized by a Proctotrupid, and the larvae by a Dipteron and a Braconid. In the laboratory larvae have died of a bacterial disease. The tobacco grown without shade is subject to the attack of the same insects as the shade grown. The flea beetles are quite as abundant and the hornworms seem to be more numerous, but owing to improper methods of combating these insects, much more damage is done to the leaf. During the past season, a good grade of dry pow51 dered arsenite of zinc was used with much success, but owing to the recent introduction of this insecticide, more experimental work must he carried on before recommending its permanent use. If this product can be successfully used, it will be a great saving to the growers due to its greater toxic effect and cheapness. During the last of March and the first of April, a trip was made to the various tobacco districts of the Island to determine the distribution of the tobacco insects. It was found that the black flea beetle was present only east of Arecibo and San German, while the brown species was generally distributed but nowhere in sufficient abundance to cause much injury. The hornworm was found everywhere, but the cutworms were confined to a great extent to the vicinity of Morovis and Ciales. Much of the tobacco on the northern and southern coasts suffered greatly from the Mosaic disease. The light at La Plata was kept burning several nights, but few tobacco insects were attracted to it. It is recommended for the coming year (1) that the life histories that are being worked out in the laboratory be continued; (2) that more extensive work be carried on in the field with insecticides and (3) that the factors governing the distribution and abundance of the various tobacco pests in all parts of the Island be determined. PUBLICATIONS AVAILABLE. Irrigation (unnumbered). 1. First Annual Report of the Experiment Station. 2. Second Annual Report of the Experiment Station. 3. Fertilizers. 4. The Salt Marshes of the North Coast of Porto Rico. 5. Third Annual Report of the Experiment Station. 6. Selection and Treatment of Cane Seed. 7. The Handling of Porto Rican Oranges, Grapefruit and Pineapples. (Limited). 8. Miscellaneous Papers on Cane and Fertilizers. 9. Salts in Soils and Waters of the South Coast of Porto Rico. 11. Aphides or Plant-lice attacking Sugar-cane. (Limited). 12. The Sugar-cane Moth Stalk-borer. (Limited). 13. Commercial Fertilizers. 14. The Sugar-cane Weevil Root Borer. (Limited). CIRCULAR SERIES. 1. Damage to Sugar-cane Juice by the Moth Stalk-borer. 2. The Nature of Fungous Diseases of Plants. 52 3. The Relation of Cane Cultivation to the Control of Fungous Diseases. (Exhausted). 4. Notice to Citrus Growers. 5. Plant Quarantine Regulations. 6. Control of the Changa. 7. The Influence of Rainfall and the Non-burning of Trash on the Abundance of Diatraea Saccharalis. REPORTS, BOARD OF AGRICULTURE. 1. Report, 1912. 2. Report, 1913. 3. Report, 1914. (Limited). MISCELLANEOUS PUBLICATIONS. Laws and Regulations Pertaining to the Importation and Inspection of Plant and Insect Diseases and Pests to the Island of Porto Rico. The Fertilizer Control Law. 53 THE UNIVERSITY OF MICHIGAN GRADUATE LIBRARY DATE DUE I I DO NOT REMOVE OR MUTILATE CARD I I t