Climate change makes heat tolerance a must-have trait for wheat in Central Asia

Date: 10.10.2013.

Winter wheat, a staple food in the region, is particularly vulnerable during flowering. Photo by Tulkun Yuldashev.

Heat stress is a major worry for farmers in large parts of Central Asia, and Uzbekistan in particular. After all, agricultural production is affected. And climate change is making things worse. Like some other crops, wheat, a staple food in the region, is susceptible to temperature variations. And it is particularly vulnerable during flowering. In Uzbekistan, local scientists and their counterparts from international research organizations work on possible solutions. They introduce, test and evaluate enhanced winter wheat lines for tolerance to heat and other stresses. A number of projects in the field have been carried out in the past, and a few are under way. For instance, a recent study called 'Adaptation to Climate Change in Central Asia and People's Republic of China', funded by the Asian Development Bank and conducted by the International Center for Agricultural Research in the Dry Areas (ICARDA) and the International Food Policy Research Institute (IFPRI), showed that a rise in air temperature in spring, and corresponding heat stress during flowering, is the main factor affecting winter wheat productivity in Central Asia. The results of this extensive research have been recently published in Agriculture, Ecosystems & Environment.

Building on this research effort, ICARDA started another project in 2012. It is called 'Testing of selected facultative wheat varieties for tolerance to heat stress during flowering'. The project brings together researchers from ICARDA and Kashkadarya Research Institute of Grain Breeding and Seed Production of Cereal Crops. The study itself is part of a larger, multi-disciplinary CGIAR Research Program on climate change, agriculture and food security, and will run until August 2015.

The project is now in its second year. Researchers are conducting field trials at experimental sites of the Institute. One is under way in Kojar village of Karshi district, Kashkadarya Region. Scientists are assessing the potential of different crop management practices (best sowing time) along with screening of improved heat-tolerant winter (facultative) wheat germplasm. They are trying to identify varieties that can resist or cope with heat stress during flowering, and to assess yield losses associated with heat stress. The project team is also doing soil and crop laboratory analyses to distinguish heat stress from other factors influencing productivity. Furthermore, crop modeling and biophysical research is ongoing in cooperation with laboratories of the Uzbek Cotton Research Institute.

During this year, the project partners did pre-sowing soil sampling and analysis of soil physical properties and chemical composition, soil moisture and soil salinity in mid-October, and planted eight varieties of facultative wheat ('Hazrati Bashir', 'Bunyodkor', 'Gozgon', 'Jaihun', 'Elomon', 'Humo', 'Sanzar 4', 'Saidaziz') on 20 October 2013 (optimal planting). The data assessed in the field will be further fed into CropSyst, a crop modeling application. There are now plans to start late and spring planting of these wheat cultivars in mid-November 2013 and mid-February 2014 respectively.

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