Why Nov-dec temperatures may decide the rabi output

IN RECENT times, wheat has often been hit by a spike in temperatures in March, just when the crop is in the final grain-formation and filling stage. In the current crop season, maximum temperatures have so far been near normal in much of northwestern and eastern India.

With more than half the grain-filling period — 30-40 days of the kernels accumulating starch, proteins and other nutrient matter — over in the major wheat-growing regions, and the crop already or nearharvested in central India, chances of yield loss due to heat seem low. “The crop expression has been overall excellent in Punjab, Haryana, UP, and Bihar. We can expect high yields and good production in these states,” Rajbir Yadav, principal scientist at the genetics division of the Indian Agricultural Research Institute (IARI), said.

Less-than-cold start

Yadav was, however, less sanguine about wheat production in central India — Madhya Pradesh, Maharashtra, Gujarat, and parts of Rajasthan. Reason: the late onset of winter.

Monthly average minimum temperatures over central India were 1.67 degree and 2.12 degree Celsius higher than normal in November and December respectively. This led to premature initiation of flowering — the crop, whose earheads bearing flowers (and eventually grain) should take 75-80 days to fully emerge from the wheat tillers (shoots), came to heading in 60-70 days.

Northwestern and eastern India too had above-normal temperatures in November and December, but the deviations weren’t as much. Also, in central India, wheat is sowed from the last week of October to midnovember, earlier than the first half of November in northwestern India, and mid-november to mid-december in eastern UP and Bihar.

The delayed winter would have affected the crop sown earlier, cutting short its vegetative growth (roots, stems, leaves) phase. The impact would have been more in central India, where the crop’s growth duration is 125-130 days, compared to 140-145 days in Punjab and Haryana.

While winter did set in fully by late December, the crop in central India suffered due to fog and a lack of sunlight in January. After having flowered early, the wheat now recorded poor pollination and seed-setting.

“There has been a reduction in the number of tillers per plant as well as seeds formed per spike( ear-head ), which may translate into lower grain yields in central India,” Yadav said.

Production effect

Laxmi Narayan Dubliya, a wheat grower from Polayjagir village in Sonkatch tehsil of MP’S Dewas district, said: “Pehle do maheeno mein vipreet mausam raha. Fasal ko thand nahi mil pa ayi( The weather was adverse in the first two months, not cold enough for the crop)”.

Dubliya, who is also a director of the Dewas Kisan Producer Company Ltd, estimated the average yield in his area for the wheat sown during November 1-15 at 20 quintals per acre, down from last year’s 25 quintals. “Those who sowed earlier, during October 20-31, harvested hardly 14 quintals. Unke aur kam shaakhayein bane (their crop developed fewer tillers),” he said.

Of the total 34.2 million he ct ares(mh) area under wheat in the 2023-24 rabi season, MP accounted for 8.7 mh, with Gujarat and Maharashtra together adding another 2.3 mh. If the lower yields from central India are offset by bumper harvest sin the northwest and east, the country can still end up producing more wheatthanin2022-23and2021-22.theneed for a better-than-average crop is more this year, given that wheat stocks in government godowns are at a seven-year low (Chart 1).

Tuber trouble, too

Potato too, has been hit by the unusually warm November-december, followed by a cold but sunless January. Doongar Singh, a farmer and cold store owner from Khandauli in Etmadpur tehsil of UP’S Agra district, said potato requires sufficiently low temperatures during planting from mid-october to midnovember to enable vegetative growth.

Even when temperatures fell in January, there was no sunlight, Singh said. Thus, not only were fewer underground tubers formed, their development through photosynthesis was impeded. “Last year, yields were 250-300 packets (each of 50 kg) per acre. This year, we got 25-35 packets fewer,” he said.

Government data show potato retailing at Rs 20 per kg, compared to its year-ago allindia average modal (most-quoted) price of Rs 10. Retail prices of onion and tomato have posted increases of Rs 20-30 per kg. In their case, dry weather and depleted water levels in reservoirs and aquifers, especially in Maharashtra and Karnataka, has led to a reduction in rabi planted acreages as well.

One sweet story

There’s good news on the sugar front, though. The last sugar year (October 2022September 2023) ended with stocks of 5.7 million tonnes (mt), the lowest since 2016-17. The current year is likely to see a production decline, and yet closing stocks recovering to a four-year-high of 8.6 mt (Chart 2).

Prakash Naiknavare, managing director of the National Federation of Cooperative Sugar Factories, said two factors were responsible. First, Maharashtra received good rain in November and December, which provided a lifeline to the standing cane. Second, the Centre’s decision in December 2023 to restrict the use of sugarcane juice/ syrup and intermediate-stage ‘B-heavy’ molasses for the production of ethanol. “These factors will contribute to higher than expected output and comfortable stocks position,” he said.