It could well be the answer to India’s arhar dal woes.
Scientists at the Indian Agricultural Research Institute (IARI) have developed a new arhar (pigeon-pea) variety that matures in 120 days, gives the same 20 quintal-per-hectare yields of normal 160-180 day plants and is, moreover, amenable to mechanical combine harvesting.
Arhar plants are mostly ‘indeterminate’; they keep growing and, left to themselves, can even become perennial trees. In Bihar and eastern Uttar Pradesh, farmers plant the crop in June-July and harvest it after 250-280 days in March-April. In other parts, especially Maharashtra, Karnataka and Madhya Pradesh, the varieties grown are of medium duration (160-180 days) and also yield 20 quintal per hectare.
What IARI scientists have now bred is a ‘determinate’ early-maturing pigeon-pea, which produces 20 quintal per hectare in just 120 days.
“It is a totally new plant-type, whose apical meristems (tissues at the tip of the main stem) only produce flowers. Unlike the indeterminate pigeon-pea plants, where the meristematic cells keep dividing and producing vegetative buds (giving rise to new leaves and shoots), here the growth stops with production of flowers and setting of pods,” K V Prabhu, joint director (research) at IARI, said.
But that’s not all. In normal arhar varieties, the flowers produced from the axillary and lateral branches do not set pods at the same time. So, even at the time of harvesting, not all the pods are mature. Some may have already shattered, others would still be developing or be even at the flowering and vegetative bud stages.
In the new plant-type — called PADT-16 (Pusa Arhar Determinate) and bred by a team led by Prabhu and R S Raje, principal scientist at IARI’s division of genetics — the flowering and pod-setting is synchronous, with the crop maturing and ready for harvest in 120 days.
“This is a short, compact plant-type that grows to hardly 95 cm height, compared to 175 cm for medium-duration arhar and 300 cm-plus for perennials. The spacing between rows, too, is only 30 cm (as against 60-70 cm in normal arhar varieties) along with lower plant-to-plant distance (15 cm versus 30-40 cm). Since there are more plants per unit area, it creates a compact canopy,” Raje said.
The benefits are two-fold.
First, being a dwarf semi-erect plant makes pesticide spraying easier. The normal arhar plants rise to six feet levels, at which application is difficult and also tends to be non-uniform. “Here, you can use a regular knapsack pesticide sprayer and ensure every plant is covered. Also, you only need to give one good spray against maruca insect and pod borer at bud initiation stage after 65-70 days,” Raje said.
Secondly, synchronous maturity and podding happening only at the top — because of the compact canopy and no tertiary or quaternary branch growth — means the entire arhar crop can be harvested at one go using combine harvesters. “This is something that the Punjab farmer would want, as in the case of wheat and paddy. An early-maturing, short, compact plant-type precisely fits that requirement,” Prabhu said.
Experts believe that India’s pulses production cannot increase to match growing demand unless farmers in irrigated regions like Punjab, Haryana and western UP take up large-scale cultivation. But that isn’t possible without breeding high-yielding varieties/hybrids amenable to mechanisation.
So, when will the new ‘super’ arhar make it to the fields? “Our immediate priority is seed multiplication. We have supplied the breeder material to the Punjab Agricultural University for further foundation seed multiplication in the coming kharif season. Once the plant variety protection for the new plant-type is obtained, we could even involve private seed companies to enable commercial cultivation by 2018,” said Prabhu. He is also the main breeder of HD-2967, a blockbuster IARI wheat variety currently grown over 10 million hectares.