Surinder Sud: Keeping a weather eye on climate

Scientists are now keeping tabs on weather abnormalities while crafting technologies to combat climate change-related challenges to agriculture

Rabi crops, which looked robust to begin with, were ransacked by freakish weather in the second half of the growing season, dimming hopes of a bumper output. Unseasonal spells of rain, hail and gusty winds from February-end onwards ravaged not only the main rabi crops such as wheat, gram and mustard but also many vegetables and fruit crops. This year, March has been abnormally cool besides being the rainiest in the past several decades. The all-India weighted average rainfall between March 1 and April 15 was more than twice the normal precipitation during this period. Worse still, over 80 per cent of the country received excess rainfall, with over one-third of the total area recording five times the normal rainfall.

Considering the frequency with which odd climatic conditions have been noticed in the past several years, it may not be impertinent to attribute them to climate change. The Solapur region in Maharashtra, for instance, was lashed by hailstorms in February-end last year also. The northern wheat belt, now extending right up to Madhya Pradesh, has often been pounded by rain when the crop is almost ripe or is being harvested. There have been umpteen occasions when the temperature tended to rise abruptly in March to cause premature ripening and shrivelling of grains, thereby, lowering the crop yield. In the 2003-04 rabi season, the mean night temperature in February and March in Haryana remained around three degrees Celsius above normal. This caused the average wheat productivity to plunge sharply from over 41 quintals a hectare to just 39.3 quintals.

The consequences of this year's inclement weather have received relatively higher media and political attention because of the extent of the affected area and the nature of damage it inflicted on crops. Besides flattening crop plants and hindering grain development, which resulted in quantitative loss, the wet bouts in quick succession also lowered the grain quality due to their discolouration and shrivelling, thus, affecting their market value. In worst cases, the seeds began to sprout before harvest.

Luckily, farm scientists are now keeping such weather abnormalities in view while crafting technologies to combat climate change-related challenges to agriculture. Incidents like the pre-harvest sprouting (PHS) of grains need special technological interventions, says Indu Sharma, head of the Karnal-based Directorate of Wheat Research. "Breeding PHS-tolerant cultivars is highly desirable for areas where long periods of wet weather occur frequently at harvest time," Sharma said in a research paper published in a recent issue of The Indian Journal of Agricultural Sciences.

This paper, authored by Sharma and four other wheat scientists, has also stressed the need to evolve technology to mitigate the effect of drought and heat on crops, which are also fairly common during the rabi season. This will require developing crop plants having genes that can make them more efficient users of available water and nutrients. Biotechnological tools are now available - and also extensively used - to breed wheat strains with genes that enable the plants to withstand various kinds of stresses. The mapping of the wheat genome, thanks to an international collaborative project in which India played a significant role, has opened up new opportunities for suitably restructuring the wheat plant on the targeted lines.

The genetic map of wheat (genome sequence) is now available in the public domain to let the scientists access the required genes to evolve genetically-modified (GM) plants. A large number of genes have already been isolated for gainful use. Numerous GM products have been field-tested and about a dozen of them have even been approved for commercial use in different countries. However, no transgenic wheat strain - containing a gene borrowed from a non-plant source, as in the case of Bt-cotton - has yet been released anywhere in the world. Once the resistance to GM crops from environment activists wanes and the tailor-made crops having the need-based genetic make-up are made available to farmers, the losses in output due to unseasonal weather aberrations would, hopefully, be curbed to a considerable extent.

surinder.sud@gmail.com