THE SUDDEN spike in temperatures since early last week is stoking concerns over the standing wheat crop, even as the Centre has projected a record production of 96.64 million tonnes (mt) and recently levied a 10 per cent import duty on the grain.
“It was looking good till around March 20. Even on March 25, when the maximum temperature rose to 36 degrees Celsius, I was confident my crop will be similar, if not better, than the one in 2013. The baali (wheat ear heads) had formed beautifully and there were enough ghundi (grain-bearing spikelets) in each of them. But the last week has changed the picture,” says Pritam Singh Hanjra, who has planted wheat on 82 of his 90-acre holding at Urlana Khurd village in Madlauda tehsil of Haryana’s Panipat.
Temperatures in this area touched 38 degrees on March 28 and crossed 40 degrees — nearly six degrees above normal — by the month-end. “This is the time when the grain is getting filled. The present heat wave could affect the size and weight, even if not the number, of grains harvested from each baali,” says Hanjra.
Wheat is mostly a 140 to 150-day crop. The crop that’s sown before around November 20 is harvested by April 15. Flowering starts in about 90 days, when the ear heads have fully emerged along with anthers containing pollen. The complete flowering and pollination process — wheat flowers are self-fertilised by the movement of pollen from the male (stamen) to the female (stigma) part of the same flower — happens within five days near February 20.
The subsequent 45 days or more is when the resultant grain develops, from the early ‘milk’ and ‘dough’ to the final hardening and ripening stages of the kernel. The real grain-filling, or accumulation of semi-solid starch matter in kernels, takes place roughly from mid-March. During this phase, day temperatures should ideally not exceed 35 degrees. When they cross that level, the grain tends to ripen.
The question being asked is whether, and to what extent, would the abrupt rise in the mercury this time cause premature ripening. This is important, given the general thumb rule that every extra day on the field during the grain-filling stage gives an extra wheat yield of 45-50 kg per hectare.
“For the last one week, temperatures are what they should have been closer to April 10. Normally, we don’t give any irrigation after March 15, but are now doing so every other day to keep the temperature around the crop down,” says Raghbir Singh, a nine-acre farmer from Randhawa Masanda village of Jalandhar in Punjab.
“I am worried, as my wheat was sown in early December after the harvesting of sugarcane. The crop is still green and grain-filling had started just around the time of this heat wave. Irrigation can help provide moisture and prevent sudden drying, but cannot replace the natural process of the grain ripening with the gradual setting in of summer,” says Rattan Singh, who farms 10 acres at Sherpur village in Hoshiarpur’s Mukerian tehsil.
“Sahaj pake, so meetha hoye (When something is cooked slowly, it tastes sweeter). Even if the crop matures a week early, it will translate into a yield loss of 1.5 quintals per acre. Last year, I harvested an average yield of 24 quintals per acre. This time, till March 25, I was hopeful of 26 quintals because the tillering, baali formation and even early grain development were so good. But now, yields could be 22.5 quintals or even less,” says Hanjra in Panipat.
However, Rajbir Yadav, principal scientist and wheat breeder at the Indian Agricultural Research Institute at New Delhi, believes that production losses due to the early onset of summer may not be much. “There could be some impact for the crop sown late. But farmers in Madhya Pradesh, Rajasthan, Gujarat, Maharashtra and Karnataka would already have harvested their wheat by the time temperatures had soared. Even in Punjab and Haryana, the crop planted before November 20 would have reached near-physiological maturity before March-end. There is no further grain-filling after that, only a reduction in its moisture content from about 17 per cent to 10-11 per cent,” he says.
On February 15, the Agriculture Ministry had estimated India’s wheat production for 2016-17 at 96.64 mt, surpassing the previous all-time high of 95.85 mt in 2013-14. The expectation of a bumper harvest also led to the wheat import duty being raised to 10 per cent, from zero, on March 28.
Whether the latest unforeseen ‘sunstroke’ will prompt a review — more so, with public wheat stocks of 9.43 mt as on March 1 at a nine-year-low — remains to be seen.