L WARY BR7& H OF THt COLLEGE OF AQRICutfljB* COFY^ UNIVERSITY OF CALIFORNIA. AGRICULTURAL EXPERIMENT STATION. BERKELEY, CAL. E. W. HILGARD, Director. BULLETIN NO. 92. J^JOTES OJM ©jftLIFORNIA OblVES: THEIf^ /eDAPTATIOJM S yVNID OlbS. In view of the constantly increasing im- maturity was very late; the variety Rubra alone portance olive culture is attaining in Califor- was just beginning to change color. This back - nia, I commenced last October, under instruc- wardness was probably due principally to their tions from Prof. Hilgard, a study of the dif- growing on low ground; for other trees but a ferent olive varieties cultivated in this State short distance away, but on high ground, and of the quantity and quality of oil pro- showed a more advanced degree of ripeness, duced by each. This shows that, especially in cool climates, The time that could be given to this subject the plantation on high ground is better suited being limited by my other duties, what I to olives because they receive there more air, considered most important was the identifi- heat and light, so much needed by these cation of the varieties; from which afterward trees. were obtained small samples of fruit used for I remarked also some damage to the crop a chemical test as to the quantity of oil each caused by a very strong wind which had blown contained, and, so far as feasible, its quality. for several days. This damage was still greater My observations were thus necessarily con- at Mission San Jose and at Berkeley, where I fined to the plantations at Berkeley, Niles and think that not only the wind but the dryness Mission San Jose, more especially to those of of the soil had contributed much to the falling- the latter, where, maturUy being earlier than off of a large quantity of olives. In fact the in the other two localities, we were enabled to rain,coming soon after, benefited somewhat the obtain samples sooner. fruit which remained shrunken on the tree, im- My first visit was made at the beginning of proving it in appearance and size. November, 1890, to the plantation of the Cali- My attention was then given exclusively to fornia Nursery Co. at Niles, where Mr. John the olive trees of Prof. Hilgard at Mission San Rock, the president of the company, kindly Jose, and there I began the identification of the showed me all the varieties cultivated and gave varieties, of which I could determine only me much information regarding the large twelve, others being too young or without collection of foreign varieties, very well cared fruit. for but with only a light crop; partly, doubtless, According to my observations, these varieties on account of their imperfect acclimation. The may be arranged as follows : 2 According to Time of Ripening. I Nevadillo bianco. 2 J Atro-violacea. "l Pendoulier. (.Pend 'l na. 2 — Redding Picholine. 3 — Manzauillo. 4 — Mission. f Polyraorpha. 5 * Oblonea. I Revalis. g f Oolumbella. \Uvaria According to Productiveness, method, in order to have a small quantity of oil for testing its character. 1 - Mission. „ f Nevadillo bianco. ■ 1 Columbella. f Uvaria. i Atro-violacea. Z \ Redding Picholine. i Oblouga. I Rega'is. ( Pendoulier. , ) Pendulina. ~) Manzanillo. ( Polymorpha. It must be remembered that, with the excep- tion of the Mission olive, most of the trees are young, and therefore the amount of the crop may not correspond exactly with what would be obtained with older trees; so these data must be taken with due allowance. In the plantation of the University at Berkeley the succession of ripening was the same as at Mission San Jose, but the fruit ma- tured correspondingly from one to four weeks later. The yield ranged from small to very small on all the trees, with the exception of the Nevadillo bianco and the Mission, which had a good crop. Some trees of the former are already about seven years old, and those of the latter are represented by two large and old specimens. All the other trees are from four to five years old. The results obtained should, however, be taken only as a preliminary experiment, and not as absolute; because the number of sam- ples of the localities represented, and the special conditions of the fruit, were not such as to give completely decisive results. Next season the tests will be arranged in such a manner as to work on numerous good and large samples from various localities in the State. We are also indebted to Mr. Geo. C. Roeding, who supplied us with six larger samples, pro- duced at the Fancher Creek Nursery at Fresno. The first samples recei ved from Fresno con- sisted of five varieties, one of which, (name unknown), had been picked November 4th. The others were the Pendulina, Nevadillo bianco, Manzanillo, Atro-violacea; while the sixth sample, of the Rubra, was picked on Feb- ruary 5, 1891. Their condition was as follows : Pendulina — In fair condition ; some olives dried and beginning to spoil; maturity far ad- vanced. Nevadillo bianco— In fair condition, but over- ripe. Manzanillo — In fair condition ; some dried olives; generally over-ripe. Atro-violacea — In good condition and at the right degree of maturity for warm climates. No name — In fair condition and over-ripe. This olive resembles somewhat the Italian Cerasola, but it is a little larger. Rubra — In very bad condition ; damaged by frost; maturity, at the right degree for warm climates. From Mission San Jose was received also a sample of Nevadillo bianco, gathered January 13, 1891. It was in rather good condition, but the maturity was a little passed. All the above samples, except the Rubra, were made into oil by the usual and practical OBSERVATIONS OX THE OILS OBTAINED. On March 13, 1891, I made the following observations on the oils obtained: From Fresno — Atro-violacea — Condition thickish, not clear; color, yellowish-brown; odor, not pronounced ; taste, rather greasy and coarse. It seems to be slow in clearing. General qualitv, fair. Nevadillo bianco — Condition, fluid, clear, but not yet bright ; color, light-golden ; odor, rather pronounced; taste, a little greasy, other- wise agreeable and delicate. It clears rapidly. General quality, fine. Pendulina — Condition thickish, not clear; color, yellowish-brown; odor, pronounced; taste, somewhat greasy but agreeable. It will take long to clear. General quality, good. Manzanillo — Condition, very fluid, bright and transparent; color, fine-golden ; odor, slightly suggestive of unsoundness ; taste, very slightly rancid, otherwise delicate. General quality, a rather good oil, clearing quickly. This sample was very small, and it was im- possible to keep it weli. No name — Condition, clear but not yet bright, ratber fluid; color, fine light-golden; odor, pro- nounced, but not altogether pleasant: taste, slightly greasy and rank; general quality, a common oil, but clearing quickly. From Mission San Jose — Nevadillo bianco — (This oil was made two months after those from Fresno). Condition, fluid and almost clear; color, rather deep-golden; odor, of fresh olives ; taste, oil too young for a close judgment, but promises to become a very fine sweet oil. From the above observations it appears that olives from the country about Fresno, like those from warm countries generally, produce a thickish oil, dark -colored, greasy and there- fore not easy to keep; moreover when made in larger quantities, this oil will not clear as quickly as did our small samples. The Nevadillo Blanco yields the best oil among the varieties from Fresno, but still inferior in quality to the same from Mission San Jose, which, although made two months later, promises to clear before or almost at the same time as the other one. In order to remedy the defects that oils made from olives growing in warm climates are apt to have, the fruit ought to be gathered when still yellowish and only just beginning to change their color. Such fruit would always produce an oil which on account of its delicate taste would have the same reputation as that ob- tained in cooler climates. If the olive-grower cares more for quantity than for quality, the olives should be gathered when black and still firm; but in no case should this degree of maturity be passed, because the oil from such olives would be of inferior quality, and sometimes also the quantity would be diminished. The following table, shows the analytical re- sults from the different samples received at this laboratory. Column 1 shows the proportion by weight be- tween pits and flesh in the fresh fruit. Column 2 shows the proportion in which pits and flesh may be made to contribute to the oil product when fully extracted. Column 3 gives the abso- lute percentage of oil contained in pits and flesh. Column 4 finally gives the results of the 5' " Iodine test " much relied upon for the purity of commercial oils, as hereinafter explained. The minimum is shown by the Atro-violacea from Fresno, which was the best-conditioned PARTIAL ANALYSIS OF SOME SAMPLES OF CALIFORNIA OLIVES AND OILS. Variety. Manzanillo Manzanillo Pendulina No Name Atro-violacea Nevadillo bianco. Nevadillo bianco. Nevadillo b'anco. No. In in Row No. 2 in Row Red'ing Picholine Mission Rubra Locality. Fresno. Berkeley. Fresno. Fresno. Fresno. Fresno. Mi sion San Jose. Berkeley. Berkeley. Berkeley. Mission San Jose. Mission San Jose. Fresno. Date of Picking. Nov. 4, 90 Jan. 3 », '91. Nov 4, '9 i. Nov. 4, '90. Nov. 4, '90. Nov. 4, '90. Jan. 13. '91. Jan 7, '91. Jan. 7, '91, Jan. 7, '91. " . 8, '91. Jan. 8, '91. Proportion of pits and flesh in fruit. Pits. Flesh. 13.0 16.0 14 8 17 6 23.7 17.5 21.0 25.0 30.5 36.5 29.0 23.5 19.5 87.0 84.0 85.2 82.4 713 82. 5 76 0 75.0 69.5 63.5 71.0 76.5 S).5 Percentage of oil in » bole fruit yielded by Pits. Flesh. .53 .51 1.04 .8* 1.19 (.16 1.' 6 1.05 1.34 1.5 19.23 21.38 17.40 16.63 13.78 18.02 23.94 22.72 18.00 21.87 19.07 17.69 Percentage of oil contained in fresh 2! 25 20 20 '8. 22, 31 30, 38 4. Iodine absorption. Oil from Oil extracted press.ng. by Carhon Bisulphide. 80.2 82.6 80.2 83 2 84.5 86.5 76.5 7^.3 77.7 73.4 80.7 86.6 72.5 83.2 80.3 73.5 81. n 74.2 raoPOETioN of tit to flesh. The first column, exhibiting the propor- tion of pit and flesh contained in the fruit of the different varieties, shows a maximum of 87 per cent of flesh in the Manzanillo from Fresno, and a minimum of 63.5 per cent in No. 2 (seedling) from Berkeley. On the other hand, the percentages of pits were 13 for the former and 36.5 for the latter. Between the Manzan- illo from Fresno and that from Berkeley there is a difference of 3 per cent both in pit and flesh; this is doubtless due to the growth of the former in irrigated land. The same can be said for the differences ex- isting between the Nevadillo from Fresno and that from Berkeley and Mission San Jose. Summarilv the varieties represented could be arranged as follows in regard to smallness of pit and largest amount of flesh: 1. Manzanillo. 2. Pendulina. 3. Nevadillo bianco. 4. No name (Cerasola?) 5. Rubra. 6. Mission. 7. Atro-violacea. 8. Redding Picholine. 9. No. 10 (seedling.) 10. No. 2 (seedling.) These determinations, which will be continued next season on all obtainable varieties, are very important, because they show especially which kinds are most suitable for pickling purposes, for which the finest and largest olives with the smallest pit are required. QUANTITY OF OIL. The next determinations were made with the object of ascertaining the quantity of oil contained in the different varieties. Of all the varieties represented in the above table, only the Atro-violacea from Fresno, and those from Berkeley, showed exactly the right degree of maturity for oil-making; hence the results obtained cannot be taken as representing exactly the respective practical values of the sev- eral kind*. However, with the exception of the Redding Picholine from Mission San Jose, the maturity of which was very far advanced, the other varieties give results which may be con- sidered as showing approximately their relative capabilities. From these determinations, taking into con- sideration the degree of maturity of the olives, it appears that the Nevadillo bianco from Berkeley and Mission San Jose contains more oil than the same from Fresno, while in the latter locality, the Manzanillo has pro- duced a little more oil than the Nevadillo; but the Manzanillo from Berkeley contains more oil than that from Fresno. sample received from that locality. It is extremely probable therefore, that these consistent differences between the Fresno olives and those from the other localities are mainly due to the growth of the former on flat and heavily irrigated ground, tending to produce watery fruit with relatively little oil, particu- larly where bottom water lies near the surface. - With respect to the quantity of oil contained in them, these varieties can, according to these tests, be arranged as follows: For Fresno. — 1, Manzanillo; 2, Nevadillo bianco; 3, Rubra; 4, Pendulina; 5, no name (Cerasola?); 6, Atro-violacea. For Mission San Jose. — 1, Nevadillo bianco; 2, Mission. The Redding Picholine cannot be taken into consideration on account of its very advanced maturity. For Berkeley.— 1, Nevadillo bianco; 2, Manza- nilla; 3, No. 10 Seedling. If we consider the quantity of oil that the pit may yield, we find the largest percentage in the Pendulina and the smallest in the Manza- nillo, both from Fresno; and glancing at the oil yield of the pits of the other varieties, we may conclude that it will be a more or less import- ant consideration, according to the purposes that the oil-maker has in view, or according to the special conditions of his locality. QUALITY OF OIL. According to European experience the oil- maker who intends to produce oil of the high- est quality must avoid, in its extraction, the grinding of the pits. The kernel contains an oil of inferior quality, which becomes rancid quickly and will spoil the fine oil from the pulp. An exception may exist in the case of varieties which, like the Mission, have abortive kernels. The crushing of the pits may of course be avoided by the use of adjustable crushers, which crush the pulp while allowing the pit to pass intact. In this manner oil of very high quality is ob- tained. Practically, the small quantity of oil yielded by the pits may be neglected, because this loss will be largely repaid by the higher price at which superfine oil can be sold. This loss, moreover, concerns only the first pressing, for the pomace can then be passed again through the mill in order to grind the pits and to have a homogeneous paste with the re- sidues from the pulp. This paste at the second pressing will give a common oil, of edible qualify, which would find a market at a lower price. I would not now advise making a third qual- ity of oil, or extracting the oil from the oil- cake, because, considering the high price of labor in California and the fact that the uses to which this product could be put are well supplied by other oils (especially cottonseed oil), the practice would not be profitable. The extraction of this inferior grade of oil may be- come practicable when the production of olives becomes large enough t^ furnish large quanti- ties of oil-cake at a low figure, in which case fac- tories for the special purpose of extracting this inferior quality might be profitably estab- lished. In considering the results of our experi- ments, the conclusion is that so far, among the varieties mentioned the Manzanillo seems to be the best for pickling and the Nevadillo best for oil. The latter variety, which, com- pared with the others, has been recognized as a very good bearer and able to flourish in climate not very favorable to it, ought to be propagated more than has been done so far. TESTS OF PURITY — IODINE ABSORPTION. The last column in the table shows some de- terminations on the " iodine absorption " by the oils obtained from pressing or by chemical way, in order to know if this method could be properly applied to discover adulterations in California olive oil. According to different authors, the ratio of iodine absorption by olive oil may vary from 79.7 to 88, while most chemists do not admit more than 84.5 as a standard and consider as adulterated every oil which passes this limit. The maximum of iodine absorption by our pressed oils was 8G.5, and in those obtained by extraction by carbon bisulphide was 86.6. All the other oils obtained by chemical extrac- tion showed the iodine absorption smaller than that of the same oils when obtained by pressing. We cannof, therefore, rely implicitly upon this method for discovering slight adulter- ations in California oils, and must extend the limit usually admitted for this factor (84.5) at least up to 86.6 for pure oils. Taking 88 0 as the extreme upper limit, it should be mentioned that among a number of samples of oil sent us by producers and others, the extreme minimum of iodine absorption was found to be 81.1, while among the highest figures were 89.2 and 92.9. Accordingly these two samples might be considered as adulterat- ed ; but as yet we reserve our judgment in the premises. In view of this uncertainty it will be well to mention here a simple and sure method by which adulteration « ith cottonseed oil (most used for adulteration) can quickly be discov- ered. It was devised by Prof. E. Bechi, direct- or of the Agricultural Station at Florence, Italy. Ithasbeen officially adopted in thechem- ical laboratories of the Italian Customhouses. This method serves to reveal the presence of cottonseed oil in all seed oils, and even in cod- liver oil. It may be briefly thus described : An alcoholic solution of nitrate of silver is made in the following way: Nitrate of silver 1 gram Alcohol at 98% 200 cubic centimeters Etliylic ("sulphuiic") ether 40 cubic centimeters Nitric acid 0.1 gram Another solution also is made of : Amylic alcohol (fusel oil) 100 cubic centimeters Pure colza (rapeseed) oil 15 cutic centimeters The reaction is made in the following way : To 10 cubic centimeters of the oil to be tested add one cubic centimeter of the silver reagent and 10 cubic centimeters of the solution of colza 011 in amylic alcohol ; stir briskly and divide the mixture so obtained into two equal parts; warm one-half for a quarter of an hour at the boiling point of water, and compare with the other half to see if there has been any change of color. In case of any addition of cottonseed oil a dark brownish-red coloration will be ob- tained. According to the author the same result may be obtained without using colza oil, but be employs it in order to obtain always a uniform coloration. As can be seen, this method is very simple and within everyone's reach. By its means we can be sure of the purity of the prod- uct we are buying. GRAPE CUTTINGS FROM FRANCE. We are indebted to the kindness of the dis- tinguished French ampelographer, Prof. V. Pulliat, for cuttings of 2L varieties of grapes, 11 of which are new to California, or verv little known. These are the following: 1. Madeleine angevine. 2. Chasselas Coulard. 3. Agostenga. 4. Pis dechevre rouge. 5. Made- leine royale. 6. Calabrese. 7. Malvoisie jaune du Piemont. 8. Schiradzouli de la Perse. 9. Persan noir de la Savoie. 10. San Antoni. 11. Raisaine. L. Paparelli. Berkeley, March 28, 1891.