PIGEONPEA
Cajanus cajan (L.) Millsp., family LeguminosaeThe pigeonpea or cajan is adapted to the tropics and subtropics where it is one of the most valuable legumes. It is cultivated as an annual for both forage and its edible beans, which are produced in abundance (Graham 1941*). It is common in India, Hawaii, and Puerto Rico and has been tried extensively in Florida and some other southern stations on an experimental basis but is not grown commercially within the continental United States (McKee and Pieters 1937). Killinger (1969) conducted tests with 'Norman' cv. in Florida and concluded that it shows promise as a seed, hay, cover, grazing, or windbreak crop.
Plant:
Pigeonpea is a pubescent, many-branched shrub (but cultivated as an annual), 4 to 10 feet or more tall, with yellow or orange papilionaceous flowers that produce brown, hairy, four- to seven-seeded, long-beaked pods, 2 to 3 inches Iong by 1/2 inch thick.
Inflorescence:
The 1 1/2 to 5-inch terminal and/or axillary raceme bears several flowers that resemble the common sweet pea in shape, but the color is yellow, red, or yellow-purple with a brownish back. The filaments elongate in the bud, and pollen is shed the day before the flower opens. Whether actual pollination of the stigma occurs before the flower opens is not clear. The majority of the flowers open between 1 a.m. and 3 p.m., and often remain open for only about 6 hours (Purseglove 1968*). Bees visit the flowers in great numbers (Wilsie and Takahashi 1934), but whether they do so to collect pollen, nectar, or both has not been reported.
Pollination Requirements:
Krauss (1932) and Wilsie and Takahashi (1934) considered the pigeon pea to be a normally self-pollinated species. However, a high degree of cross- pollination, ranging from 5 to 40 percent, has been observed (Wilsie and Takahashi 1934, Purseglove 1968*, Matta and Dave 1931, Krauss 1927, Shaw 1932, Abrams 1967).
There is no information on the need for pollinating agents in the production of seeds. Apparently, seeds can be produced when insects are excluded from the flowers (Abrams 1967), but whether production by plants where pollinating insects are excluded is equal to open pollinated plants has not been determined.
Pollinators:
Abrams (1967) stated that bees visit the flowers in large numbers. He also indicated that thrips might be of some significance. Purseglove (1968*) stated that the flowers are visited by "bees and other insects," and Wilsie and Takahashi (1934) stated that bees visit the flowers in great numbers. These references indicate that, if insect pollination is beneficial in pigeonpea seed production, there should be no problem in building up a high bee population on the crop.
There is no proven value of pollinating insects to pigeonpeas, even though the evidence indicates these insects might be of value.
Pollination Recommendations and Practices:
None.
LITERATURE CITED:
ABRAMS, R.
1967. STUDIES ON NATURAL CROSS-POLLINATION IN PIGEONPEAS (CAJANUS CAJAN). Puerto Rico Univ. Jour. Agr. 51(1): 1-3.KILLINGER, G. B.
1969. PIGEONPEAS (CAJANUS CAJANS (L.) DRUCE)- A USEFUL CROP FOR FLORIDA. Soil Crop Soc. Fla. Proc. 28: 162-167.KRAUSS, F. G.
1927. IMPROVEMENT OF THE PIGEONPEA, GENETIC ANALYSIS OF CAJANUS INDICUS AND THE CREATION OF NEW VARIETIES THROUGH HYBRIDIZATION AND SELECTION. Jour. Hered. 18: 227-232.______ 1932. THE PIGEONPEA (CAJANUS INDICUS) ITS IMPROVEMENT, CULTURE AND UTILIZATION IN HAWAII. Hawaii Agr. Expt. Sta. Bul. 64, 46 pp.
MATTA, D. N., and DAVE, B. E.
1931. STUDIES IN CAJANUS INDICUS. India Dept. Agr., Mem. Bot. Ser. 19, 25 pp.MCKEE, R., and PIETERS, A. J.
1937. MISCELLANEOUS FORAGE AND COVER CROP LEGUMES. U.S. Dept. Agr. Yearbook 1937: 999-1031.SHAW, F. J. F.
1932. THE BREEDING OF CICER AND CAJANUS. Imp. Burl Plant Genet., Herbage Plants Bul. 7: 14-16.WILSIE, C. P., and TAKAHASHI M.
1934. NATURAL CROSSING IN THE PIGEONPEA. Jour. Agr. Res. 49: 923-927.
