Grandules
Specimen
Grandules. "Pigeon Peas” (Cajanus cajan). Dried specimen. 9 x 22 cm. Collected Miami (south east) February, 2003. Specimen courtesy Sr. Luigi Ferrer.
Nomenclature
Pigeonpea (En), Grandules (Es), Pois d' Angole, Pois d' Congo (Fr), Cajanus cajan (L.) Millsp. The 32 species were grouped by van der Maesen (1986) into six sections based on growth habit, leaf shape, hairiness, nature of corolla, pod size, and strophiole characteristics.
Description
Pigeonepea is a perennial erect bush, 0.5 to 4 m tall, and has strong stem. It has pubescent leaves which are trifoliate. Leaflets possess vesicular glands below, which are membranaceous or rather tick. Stipellae are present or absent. Flowers are present in axillary or terminal pedunculate or almost sessile racemes. They are yellow, or lined with red, or flag is dorsally reddish, and upto 3 cm long. Bracts are small or large, caducous; bracteoles absent. Calyx are teeth acute, acuminate or elongate-acuminate; two upper ones more or less connate. Coralla are persistent or not, vexillum obovate-orbicular, reflexed, clawed, auriculate. Wings are obliquely obovate auriculate, keel rounded-oblique, obtuse. Ovary is subsessile with 3 to 10 ovoules. Style is thickened above the middle, upcurved, upper part glabrous or slightly hairy, not bearded. It has 9 stamens which are connate; vexillar is stamen free and anthers are uniform. Its fruit is a pod, linear-oblong, apex obtuse or acute, compressed, bivalved, depressed between the seeds with transverse lines, more or less septate between the seeds. Its seeds are reniform to suborbicular, shiny, white, brown, grey, purple or black, variegated or not, strophiole conspicuous or vestigial. It has deep, strong, woody tap root with well developed lateral roots in the superficial layers of the soil. It is nodulated by the cowpea group of Rhizoibum. Most nodules may vary from 2mm to 2 cm, and the shape be spherical, oval, elongate, or branched. Distribution
Pigeonpea seems to have originated in peninsular India. It is part of many farming systems throughout the tropics and sub-tropics. Although India produces around 80% of the total crop, 2.6 million t from nearly 3.5 million hectares, it is also grown less intensively for instance in home-gardens, elsewhere in Asia, throughout Africa, and in Latin America. There is substantial area of pigeonpea in Kenya, Uganda, and Malawi in eastern Africa, and in the Dominican Republic and Puerto Rico in Central America. Cajanus cajan grow as tall as small trees and are used as a staple food in most Latin American locations.
Adaptation
Pigeonpea can be found growing on an otherwise arid landscape due to its ability to tolerate drought and high temperatures. Its deep root system allows for optimum moisture and nutrient utilization and break the plough pans, thus improving soil structure. It seems to have special mechanism to extract phosphorous from some soil to meet its needs. It depends on symbolically fixed N part of which (up to 40 kg N ha-1) is left as residual for the use of following crops. Its fallen leaves enrich soil organic matter. This crop is ideal for intercropping or mixed cropping because of its slow initial growth allowing companion crop, usually a coarse grain cereal, to grow unhindered. It makes major growth utilizing the residual soil moisture left after the harvest of companion crop. Local land races and cultivars of 180 to 280 days duration are often grown in this manner to exploit residual moisture in soil when it is not feasible to raise another crop in South Asia. Elsewhere, they are generally grown as perennial hedge crop. Their photoperiod sensitivity allows them to be grown as a winter crop in mild winter environments.
Short-duration pigeonpea takes 100 to 140 days to mature has been recently introduced in India now make it possible to grow a sole crop of pigeonpea before the major postrainy-season crop of wheat is sown. This was not possible earlier with the traditional, long-duration pigeonpeas. The perennial habit of short-duration pigeonpea enables the production of multiple harvests in tropical areas.
Cultivation is confined to mainly tropical and subtropical latitudes within 30∞ N to 30∞ S. Recently developed extra-short duration cultivars are relatively less sensitive to photoperiod which enables their cultivation up to 45∞ N latitudes.
Other major research topics
A number of putative souces to individual and multiple disease resistance have been identified. Efforts are being made to improve resistance to key pests such as maruca, pod borer and pod fly both in Asia and Africa. Work on enhancing drought and waterlogging resistance has been in progress.
Pigeonpea (Cajanus cajan (Millspaugh) is one of the major grain legume crops of the tropics and subtropics. Endowed with several unique characteristics, it finds an important place in the farming systems adopted by small farmers in a large number of developing countries. Although pigeonpea ranks sixth in area and production in comparison to other grain legumes such as beans, peas, and chickpeas, it is used in more diverse ways than others. Besides its main use as dhal (dry, dehulled, split seed used for cooking), its tender, green seeds are used as a vegetable, crushed dry seeds as animal feed, green leaves as fodder, stems as fuel wood and to make huts, baskets, etc., and the plants are also used to culture the lac-producing insect. It is grown on mountain slopes to reduce soil erosion. Pigeonpea seed protein content compares well with that of other important grain legumes.
All the evidence gathered to date points to peninsular India as the place where pigeonpea originated. The name "pigeonpea" probably originated in the Americas, where it reached sometime in the 15th Century, because the seeds were found to be favoured by pigeons. It is now widely grown in the Indian subcontinent that accounts for almost 90% of the world's crops. Other regions where pigeonpea is grown are Southeast Asia, Africa, and the Americas. There is substantial area of pigeonpea in Kenya, Uganda, and Malawi in eastern Africa, and in the Dominican Republic and Puerto Rico in Central America. In most other countries pigeonpea is grown in small areas and as backyard crop.
Pigeonpea can be attacked by more than 100 pathogens. These include fungi, bacteria, viruses, nematodes, and mycoplasma-like organisms. Fortunately, only a few of them cause economic losses, and the distribution of the most important diseases is geographically restricted. At the present farmers mainly grow pigeonpea landraces and it is possible that they have some degree of tolerance to most of the pathogens. This situation could change once the diverse landraces are replaced by a few improved cultivars. The diseases of considerable economic importance at present are sterility mosaic (SM), fusarium wilt, phytophthora blight (PB), macrophomina root rot and stem canker, and alternaria blight on the Indian subcontinent; wilt and cercospora leaf spot in eastern Africa; and witches' broom (WB) in the Caribbean and Central America. Sterility mosaic, the most important disease on the Indian subcontinent, is not found in eastern Africa. Similarly WB is absent from two major pigeonpea-growing regions; the Indian subcontinent, and eastern Africa.
The seeds, and other parts of the plant, are fed upon by many insects, with over 200 species having been recorded in India alone. Some of these insects cause sufficient crop losses to be regarded as major pests, but the majority are seldom abundant enough to cause much damage, or are of sporadic or localized importance, and as such may be regarded as minor pests. In addition, hundreds of other species of insects and other animals are found in pigeonpea plants and many of these are beneficial, for they feed upon the pests, either as predators or parasitoids. Insects are found chewing or sucking pigeonpea plants from seedling to harvest, and no part of the plant is immune to attack. Plants that are heavily attacked before the flowering stage can lose a large proportion of their leaf area and will appear to be very badly damaged. However, pigeonpea has been described as a very forgiving plant, for it can recover from many setbacks.
Most pigeonpea genotypes produce an over abundance of buds and flowers, and most of these will be shed, so the loss of a large proportion to insect attacks may not result in measurable yield loss.
For more information see The International Crops Research Institute for the Semi-Arid Tropics (ICRISAT) and thier pigeonpea taxonomy
fl;1898;03;ppa, b, and c. Formerly catalog entry #5.
