3'A(* /- HAWAII AGRICULTURAL EXPERIMENT STATION \ D J. ]VL WESTGATE, Agronomist in Charge, Honolulu, Hawaii. BULLETIN No. 46. Under the Supervision of the STATES RELATIONS SERVICE, Office of Experiment Stations, U. S. Department of Agriculture. THE PIGEON PEA (CAJANUS INDICUS): ITS CULTURE AND UTILIZATION IN HAWAII. BY F. G. KRAUSS, Superintendent of Extension Division. Issued December 16, 1921 /X^fe %^n*^ TOrM nofoJli/lENTS ObPT, ru i \ WASHIN GTON: S. DEPOSITORY ^^flSOVERNMENT PRINT4N«-OFPJ€fi-. 1921. . HAWAII AGRICULTURAL EXPERIMENT STATION J. M. WESTGATE, Agronomist in Charge, Honolulu. Hawaii. BULLETIN No. 46. Under the Supervision of the STATES RELATIONS SERVICE, Office of Experiment Stations, U. S. Department of Agriculture. THE PIGEON PEA (CAJANUS INDICUS): ITS CULTURE AND UTILIZATION IN HAWAII. BY F. G. KRAUSS, Superintendent of Extension Division. Issued December 16, 1921 s^fr^mfu WASHINGTON : GOVERNMENT PRINTING OFFICE. 1921. HAWAII AGRICULTURAL EXPERIMENT STATION, HONOLULU. [Under the supervision of A. C. True, Director, States Relations Service, United States Department of Agriculture.] E. W. Allen, Chief, Office of Experiment Stations. Walter H. Evans, Chief, Division of Insular Stations, Office of Experiment Stations. STATION STAFF. J. M. Westgate, Agronomist in Charge. F. G. Krauss, Superintendent of Extension Division. H. L. Chung, Agronomist. W. T. Pope, Horticulturist. J. C. Ripperton, Assistant Chemist. R. A. Goff, In Charge of Glenwood Substation and Extension Agent for Island of Hawaii. THE PIGEON PEA: ITS CULTURE AND UTILIZA- TION IN HAWAII. 1 CONTENTS. Page. Introduction ; 3 Botany and agricultural history 5 Climatic and soil adaptations 7 Planting 8 The hay crop 9 Harvesting 9 Curing 10 The seed crop 13 Harvesting 13 Thrashing 14 Page. Pigeon pea as feed 15 Feeding value 15 Milling and mixing feeds 16 Suggested feeding rations 18 Plowing under of pigeon peas 20 Pigeon peas as a cover and green- manuring crop, and for rotation— 20 Pests and diseases 22 INTRODUCTION. The pigeon pea, also commonly called the Porto Rican pea, was introduced into Hawaii from Porto Rico. It has been grown in a limited way in Hawaii for at least 20 years and is now commonly cultivated as a back-yard shrub. It does not appear, however, to have been thought of as a field crop until comparatively recently. Between the years 1906 and 1908, the Hawaii Experiment Station grew several varieties or types of pigeon peas as an experiment ; and in a comparative test with leguminous field crops that had been given extensive trials the pigeon pea was found to attract especial atten- tion on account of its vigorous growth and heavy seeding qualities. In the experiment just referred to, three test rows, each 100 feet long, were spaced 10 feet apart. The middle row was planted to the variety known at the station as No. 218, which yielded 102 pounds of prime seed within eight months from the time of planting. This was at the rate of 1.02 pounds per running foot of row ; and if cal- culated to acre yields, the product would amount to nearly 2 J tons of shelled seed per acre. The plant, being a perennial, yielded two subsequent crops which were harvested within the succeeding 12 months, the combined yield of seed approximating that of the initial crop. The seed of this variety (No. 218) was well distributed and undoubtedly is now to be found growing in widely scattered sec- tions of the islands. x See also Hawaii Sta, Bui. 23 (1911), pp. 21-23. 3 HAWAII EXPERIMENT STATION. As early as 1910, reports from Fred S. Lyman, of Pupakea, Oahu, and others stated that the stems of the pigeon pea and the accompany- ing seed in pod, when harvested and fed fresh from the plant, were proving an excellent feed for work horses, mules, dairy cows, and poultry ; and that all kinds of stock browse freely upon the growing plants. Of the pigeon pea as a green manuring and cover crop, C. G. White, of Haiku, Maui, wrote in 1910 : It is the hardiest legume of all I have tried at Haiku. It maintains itself for years, and no insects have seriously bothered it so far. It does not start well when planted in winter, but November plantings loiter along and grow vigorously at the coming of warm weather. Its chief drawback is its size. With special care and arrangements, plowing one-half acre a day, I have turned it under fairly well when four years old, using a disk plow and four large mules. * * * In three months' time the plants had rotted so that it gave no trouble in replowing and fitting the land in good shape. * * * The best corn I ever grew followed these peas. James Munro makes the following statements regarding the use of pigeon peas : Pigeon peas have been used on this ranch (Molokai) since 1910, first as a windbreak and later as a soil renovator in worn-out corn fields. The crop was found to be a good soil renovator, but expensive when bringing the land back into cultivation on account of the rank growth, which left very heavy stumps to be disposed of. The pigeon peas are planted at 800-foot elevations in rows 4 feet apart in clean cultivation, either in the fall or spring, giving preference to the fall because there is more time available then. Rainfall averages about 32 inches yearly and the fields are favored with the trade rains in March and April, during which months there is an average rainfall of 5 to 6 inches. Under these conditions pigeon peas make a rank growth, and so long as the soil does not get too hard they will last through a dry summer with stocking after the grasses have failed. The fenced, 60-acre lot used for the soil renovation test was used at the same time for fattening steers for market. Not more than 60 head were allowed on the lot at one time. These got very fat and the field could have carried more. Pigeon peas should not be pastured until the plants have flowered and the pods are beginning to set, because it is on the pea pods that the cattle graze. They will also eat the leaves when hard up for feed, but in this case they will break down and destroy the plant. The freckled variety has proved an excellent chicken feed. The chickens were turned out in the peas, and the bushes beaten in dry weather to thrash out the peas. Two varieties have been grown together here without seeming to cross. The great thing about pigeon peas is, like corn, to get it through its early stages without its being destroyed by caterpillars. Although the Hawaii Experiment Station had advocated the pos- sible value of the pigeon pea as a field crop as early as 1907, and had been instrumental in getting under Way the field plantings above noted, little or no progress was made in Hawaii with it as a field crop, so far as can be determined, until the establishment of the Haiku demonstration and experiment farm on the island of Maui in 1914. Land on that island that failed to produce 25 bushels of THE PIGEON PEA! CULTURE IN HAWAII. 5 corn per acre after receiving the best cultivation produced a very fine crop when it was planted to pigeon peas under the same condi- tions. In the succeeding three years 20 acres was planted to pigeon peas, which were regularly harvested as a seed and forage crop. Five tons of seed has been distributed for planting, 100 tons of hay cured, and half the above-mentioned amounts of hay and grain have been milled and fed, either alone or in combination with other feeds to all kinds of live stock. In 1918 and 1919 fully 500 acres was planted to the crop on the island of Maui, and by the end of 1920 more than 1,000 acres was growing in the Haiku district alone. During 1919 one Haiku ranch harvested more than 10 tons daily from 350 acres planted to this crop. This was cured and milled in an up-to-date milling plant, and formed the basic constituent of hundreds of tons of mixed feed turned out during the past year. The managers of a Lanai ranch have become so favorably impressed with the possibilities of this new crop that they have under way plantings covering an aggregate of 2,000 acres. A Molokai ranch has marketed some of its best conditioned steers from pigeon-pea pasture. At the Haiku demonstration and experi- ment farm, work mules, horses, milk cows, swine, and poultry were fed pigeon peas as a large part of their ration covering a period of four years. Corn, in 100-bushel crops, and pineapples, in 20-ton crops, were grown on lands that were renovated by the culture and turning under of pigeon peas after the peas had served well their purpose first as a harvested crop, then as a pasture, and finally as green manure. BOTANY AND AGRICULTURAL HISTORY. The pigeon pea {Cajanus indicus or C. cajan) is an erect leguminous shrub, attaining a height of 3 to 10 feet under ordinary culture in Hawaii. The leaves are 3- foliate, the racemed flowers either yellow, or red and yellow, and the ovary is subsessile and has few ovules. The pods vary greatly in size and shape in the different varieties, but are usually 3, 4, or 5 seeded and constricted between the seeds by oblique linear depressions. When not crowded, the plants branch freely well to the base. The stems are slender but heavily foliaged in most varieties, and especially so after the plant has been cut back in the first harvest. The generic name Cajanus is derived from the Malayan name, Katjang, and the only species is C. indicus or C . cajan. Some doubt exists as to whether this species was originally a native of India or of tropical Africa. It is extensively cultivated throughout India, even up to an altitude of 6,000 feet. In Porto Rico, whence the first seeds planted in Hawaii came some 20 or more years ago, two prin- BULLETIN 46, HAWAII EXPERIMENT STATION. cipal varieties are recognized. The variety now known at the station as No. 218 (probably C. indicus fiavus) produces rather small seed similar to that of the Iron or Clay cowpea (PL I, fig. 1). It is a heavy seed bearer and very much liked by Porto Ricans as food, either as green peas, or as dry-shelled peas, which are prepared very much the same as cowpeas are in the Southern States. Station variety No. 219 (probably C. indicus bicolor) has yellow flowers tinged with red (PL I, fig. 2). These are in direct contrast to the pure yellow flowers borne by No. 218, and the pods are streaked or blotched with red on a green background. The seeds are light gray and faintly speckled. They are also somewhat larger and more spherical than the solid red seeds of variety No. 218. The main economic agricultural distinction, however, as now recognized, is that No. 218 is early maturing and very heavy seeding, yielding a heavy crop of seeds within seven or eight months from the time of planting, but attaining in the second year a height of only 3 or 7 feet. On the other hand, variety No. 219 does not begin to yield its maximum crop of seed until the second year, but since it is heavily foliaged and attains a height of from 6 to 10 feet, it is valuable as a temporary windbreak as well as for forage and green manuring. Special reference should be made to the root system of the pigeon pea. The plant is furnished with a long taproot and many branch- ing lateral roots that are abundantly supplied with large clusters of nitrogen-storing nodules. These nodules in some instances ex- ceed the number found on any other of the many legumes studied at this station. No case has come under observation where the seed of pigeon peas required artificial inoculation. The root nodules seem to be present naturally and without exception. The pigeon pea shows considerable tendency to cross-pollinate when several varieties are grown together. This results in the forma- tion of numerous crosses showing a greater or less variation in char- acters. Comparatively few of these appear to be constant, although several superior types have been established and are new being propagated with a view to wider distribution. While only slightly variable within the old-established varieties, such as that known as No. 218, careful selective breeding has established a superior and very uniform strain of an early maturing, heavy seeding type which the station has designated "New Era." A field of 5 acres of this strain is being grown for seed. Alonzo Gartley, of Honolulu, called attention to four well-estab- lished varieties of the pigeon pea, which he designates as (1) the Oahu type (apparently station variety No. 218 before its pres- ent improvement) ; the Maui type (apparently station variety No. 219) ; (3) the Hawaii type (apparently the small-seeded India va- riety which was first introduced by the experiment station of the THE PIGEON PEA: CULTURE IN HAWAII. 7 Sugar Planters' Association, and the seed given some years ago to the writer by H. L. Lyon; and (4) the Kauai type (which is similar to the Maui type, excepting that the seed is larger and lighter colored than the Maui type). CLIMATIC AND SOIL ADAPTATIONS. The pigeon pea is primarily a dry-land crop, especially when it is considered mainly for seed production. The heaviest yields of seed have been produced at Haiku during warm, dr}^ seasons. Where the soil is of reasonable depth and fertility and in fair tilth the plants thrive remarkably well even during protracted droughts such as pre- vailed in the Haiku district during 1918 and 1919. A fine crop planted March 15, 1919, and photographed October 15, 1919, devel- oped to perfect maturity on a total of less than 20 inches of rainfall. (PL II, fig. 1.) Only one cultivation was given the crop after the intercrop of corn was harvested in 'July. (PL II, fig. 2.) No other crop is known that would prove so successful under like conditions. Doubtless many people will recall having seen neglected pigeon pea plants thriving as well in dry, stony places as though they were being cultivated in a garden. Although suited to dry conditions, the pigeon pea adapts itself to many and varied conditions. Adequate moisture merely adds to the luxuriance of its growth and if, in addition, the soil is rich, the seeding period will merely be delayed to a time when the plant is unable to bear more foliage. Excessively wet districts, for example, Glenwood, on the island of Hawaii, and Nahiku, on the island of Maui, are, however, not adapted to the profitable culture of the pigeon pea, nor is the crop adapted to irrigation farming. As stated before, its great value rests upon its ability to produce abun- dantly and most economically a nutritious herbage under semiarid conditions. Such conditions at best would be adverse to most other forage crops. Its range of adaptability to the seasons, to varying altitudes, and to an almost unlimited variety of soil conditions is one of the striking characteristics of this unique field crop. At the Haiku demonstration and experiment farm spring and fall plantings have been equally successful. When planted in February, March, or April the plant begins to bear its first crop of seeds from August to October and con- tinues to flower and fruit well into midwinter, provided the pods are kept picked. No treatment other than that of keeping the maturing pods continually picked will cause heavy fruiting and large yields of seed. Spring is considered the most favorable time for planting pigeon peas, because the plants then start growth rapidly and branch rather freely. Furthermore, at this season of the year a wide selec- tion of crops is available for intercropping with the pigeon pea. 8 BULLETIN 46, HAWAII EXPERIMENT STATION. Planting in August, September, or October, to follow the corn or other summer harvests, is practicable when the ground contains suffi- cient moisture to germinate the seed. However, no intercropping should be attempted with fall planting of the pigeon pea. If the fall planting is followed by either an excessively dry or wet fall and winter, the crop will, as C. G. White has stated, "loiter along" for awhile and then start off vigorously at the coming of warm weather. Such plantings often produce the strongest legumes. They may be- gin to flower as early as May and yield seed abundantly by early July, especially in the more protected lowlands where the soil is light and well drained. Under such conditions the fruiting season may continue for a period of six months, from July to December. The following year, both from spring and fall plantings, two dis- tinct fruiting seasons, the spring and summer crop and the fall and winter crop, will have established themselves. Under unusual con- ditions the plants may continue to flower and bear seed throughout the year. In its adaptation to a wide variety of soils, the pigeon pea is equalled by few other crops. A deep, well-drained, medium rich loam is conducive to the best development and longest life of this crop; however, it thrives in light, loose, sandy soils having scant moisture from the gravelly and stony type to heavy clay loams of close texture and considerable moisture content, provided there is no standing water on the ground. Furthermore, the crop seems to be tolerant of salty soil conditions, plants having been noted to thrive in soils containing fully 0.0005 gram of sodium chlorid per gram of soil. In soils containing twice this amount of salt they were dwarfed and failed to seed freely, while a content of 0.005 gram of sodium chlorid per gram of soil seemed to be wholly destructive to growth. It is thought that many of the extensive barren sandy wastes border- ing the seashore might be reclaimed and made of great use by plant- ing them to pigeon peas. Seed stocks are being widely distributed at present with a view to testing further the adaptability of the crop to these conditions. It has already been shown that the crop finds a natural habitat in the lowlands, but it is by no means confined to low elevations. It is stated that in the Himalayas, the pigeon pea plant thrives at an altitude of 6,000 feet. In Hawaii thriving plants have been found at an elevation of 3,000 feet. PLANTING. It is advisable to prepare the land thoroughly before planting it to pigeon peas. After the crop is established, little or no cultivation is required to get good results from it, but the young plants start off slowly and make only a spindling growth for the first month or Bui. 46, Hawaii Agr. Expt. Station. Plate I. OJQ. < -J ~3 < LL Bui. 46, Hawaii Agr. Expt. Station. Plate 1 1, Fig. I.- -Pigeon Peas Interplanted with Corn. The Corn was Removed and Crop Shown Below in Figure 2 was Produced. Fig. 2.-Pigeon Peas Grown for Seed. Yield I Ton of Seed per Acre. THE PIGEON PEA: CULTURE IN HAWAII. 9 two. During this period it pays to run a one-horse cultivator be- tween the rows to keep down the weeds, and for this reason the rows should be spaced evenly. This can easily be done if a " marker " is used. A marker can be made by spiking three 2 by 6 inch runners, 24 inches long, to the underside of a 2 by 12 inch plank, 10 feet long, one runner being placed at each end of the plank, and one in the center. A light wagon tongue should then be fastened to the plank and a steady team used to drag the marker. The one-horse seed drill will have an accurate guide to follow. A skillful driver should mark off 20 acres a day. If the planting is to be done in rough ground where plowing and tillage are impracticable, holes can be dug approximately 5 by 5 feet apart and several seeds dropped in each hill. When pigeon peas are grown for seed purposes it is recommended that the rows be spaced 4 or 5 feet apart, depending upon the fer- tility and moisture conditions of the soil. Naturally the more favor- able the growing conditions are, the larger the plants will be and the more space they will require for best development. At Haiku, the seed is planted in rows 5 feet apart and intercropped with some quick- maturing crop such as corn, beans, potatoes, peanuts, and the like. By the time these are harvested, the pigeon peas begin to occupy the intervening space. If the crop is wanted for green manuring, it is advisable to space the rows only half as wide as when the crop is to be grown primarily for seed; that is, they should be 24 to 30 inches apart. The best and most economical method for planting the seed found so far is the use of a one-horse seed drill adjusted to drop the seed approximately 6 inches apart. This is considered the most favor- able distance in the row for seed production. With this equipment a skilled workman should readily plant from 4 to 5 acres per day. From 8 to 10 pounds of seed will plant an acre. The seed may also be broadcasted, but such a practice is not recommended. Weeds are likely to smother the young seedlings, and if the plants are over- crowded, seed production will be seriously curtailed. Furthermore, light seeding is essential to make the scant available moisture ade- quate for even so drought resistant a crop as the pigeon pea. THE HAY CROP. HARVESTING. The best time to harvest the pigeon pea crop for hay is when a large percentage of the pods is mature because a large part of the nutritive value of the plant is contained in the seed. So heavily do some strains seed that fully one- fourth of the forage is made up of grain. One great advantage of the pigeon pea over many other 52573°— 21 2 10 BULLETIN 46, HAWAII EXPERIMENT STATION. leguminous seed crops is that its pods do not shatter their seeds even when they are roughly handled. Since the pigeon pea produces a stiff, woody stem, it has been found desirable to harvest not more than the upper third, or. at most, the upper half of the plant, unless the plants are very spindling and sparse, as they sometimes are on poor thin soils during a dry season. It has been the practice at Haiku to cut back about one- third in the first harvest and a third to a fourth in subsequent har- vests, depending upon the growth made by the plants. The stems in such cases do not exceed the thickness of a lead pencil, and they bear practically all the pods on the plant at that time. The greatest problem thus far encountered is in the mechanical part of the harvesting. No ordinary mowing or harvesting machine now on the market will handle the crop as it is being grown at pres- ent. A short-knifed wheat header, such as is used in harvesting wheat and barley in California, if especially strongly built, has been suggested as a practicable contrivance. The Haiku ranch, which has several hundred acres in pigeon peas, has had underway, with some likelihood of success, the modification of a modern corn har- vester. Doubtless, when the acreage becomes large enough, imple- ment manufacturers will become sufficiently interested to undertake the manufacture of a suitable implement. In the meantime, the most practical way thus far devised is to cut the stems by the use of the short, strong-bladed, Chinese grass hook, or sickle. The workman grasps a cluster of stems with his left hand and readily cuts through the stiff stems with a strong, swift, drawing motion of the sickle blade. The handful of fodder is then laid upon the cut surface of the plant from which it was just harvested. The plants thus serve as an admirable support for wilting of the fodder preparatory to loading it on the curing trucks or stacking or for holding the fresh- cut material for immediate gathering by the crew following the cutters. These temporary supports are usually about waist high. Loading the crop on the curing truck, or on wagons for haulage, presents another difficulty, and as now done by hand, is slow and uneconomical. The present methods of loading the green pigeon pea stems are shown in Plate III, figure 1. Bundles making an armful for a man weigh about 40 pounds. They can not be handled with a pitchfork because the mass does not well hold together. The California grain-header idea might help to solve this problem, since the crop as harvested would be elevated directly into the accompany- ing wagons. te te CURING. The most practical and efficient way to cure the crop is by means of portable curing trucks and stationary raised platforms, the latter built at convenient places in the field. Under this system, the mate- THE PIGEON PEA.* CULTURE IN HAWAII. 11 rial to be cured is supported a foot or more above the ground. The floor is slatted, and all four sides are open to free circulation of the air and wind. It is the action of the wind even more than that of the sun which makes for a well-cured slack of hay. At Haiku it is the practice to load as soon after the forage is cut as is practicable, often within an hour after harvesting. However, if no wind is blow- ing, which is seldom the case at Haiku, and the fodder is exception- ally lush or succulent, it may be left lying on the plants as above described for a half day or so. If the sun is bright, fully half of the free moisture in the forage will have evaporated in this time. Ordinarily, however, the crop is loaded within an hour or two of harvest, and where sound judgment is exercised no spoilage results from the practice. When excessive rains occur during the 7 to 10 days required for curing under favorable conditions, tarpaulins are thrown over the top of the stack, but not over the sides, because as free a circulation of air as is possible is needed to prevent overheating and consequent spoilage. Some drawbacks were found to the use of impervious coverings when they were placed over a freshly stacked load of pigeon peas; and it was feared that spoilage would result if such coverings were left on too long. This would undoubtedly be the case were a protracted wet spell to occur while the coverings were on. To overcome this difficulty, Dr. W. D. Baldwin, of Haiku, suggested the use of grass-thatched coverings or roofs, which, while they allowed free circulation of air, at the same time provided perfect pro- tection against the heaviest rains. Through Dr. Baldwin's interest in advancing this work, it was possible to construct the experimental structure shown in Plate III, figure 2. It was first thought that the thatched " blanket " could be used as a tarpaulin, but it was found too cumbersome for this purpose, and it was placed over a frame of bamboo as a permanent structure. It was of just the right dimen- sions to permit the loaded curing truck to pass under. After having been used for a year or more with the utmost satisfaction, this pro- tection, unfortunately, was wrecked by a severe windstorm. Its total initial cost, ma inly for labor, was about $40, and there is no doubt that it saved five times that amount in preventing loss when hay was being cured in bad weather. This method is recommended for trial to all who are interested in the curing of any kind of forage in rainy districts. The Haiku ranch is now curing hundreds of tons of pigeon-pea hay in large, open sheds, and from these the cured hay is either baled or ground. This method i> apparently proving entirely satis- factory. II '