Physiological attributes based resilience of wheat to climate change

Climate change may affect wheat positively or negatively when global warming is likely to increase evapotranspiration (ET) and decrease crop physiological functions. More often droughts are being encountered in Pothwar because of high ET and low precipitation in the form of rainfall. The impact of climate change on physiological attributes [Net photosynthesis(An), stomatal conductance(gs) and transpiration (E)] of spring wheat in Pothwar was studied through field experiments conducted at National Agriculture Research Centre (NARC), Islamabad, Barani Agriculture Research Institute (BARI), Chakwal and at farmer's field Talagang over two years (2008-2009 & 2009-2010). The treatments consisted of five planting windows, three genotypes arranged in Randomized Complete Block Design (RCBD) factorial replicated four times. The results revealed that changing environment and sowing dates changed the adaptability pattern of wheat crop at three locations, because of change in the temperature and rainfall over the phenological stages of wheat. The reduction in net photosynthetic rate during 2009-2010 was 21% compared to 2008-2009, while among locations 20% decrease in An was recorded at Talagang from maximum value at Islamabad. The gs dropped to 50% during 2009-2010 due to temperature and moisture stress, while 92% reduction in gs was recorded at Talagang compared to highest value. However, transpiration rate dropped to 71% during 2009-2010, while among locations crop showed minimum transpiration (79% less than maximum) at Talagang. At Chakwal significant decrease in crop physiological parameters declined the grain yield. Talagang being the low rainfall and relatively higher temperature area of Pothwar produced the lowest yield due to drop in physiological functions of crop and reduced LAD and LAI. Findings of the present study provided support for further physiological investigations and potential strategy for minimizing the climate risk especially in rainfed agriculture.