Rapid screening technique for canopy temperature status and its relevance to drought tolerance improvement in chickpea uri icon


  • Field studies were conducted in Andhra Pradesh, India, during the 2006/07 post-rainy season, to evaluate the use of thermal imagery systems for capturing the genotypic differences in canopy temperature and optimize the system for the development of a simple screening method to screen for drought tolerance based on better transpiration in chickpea. Sixteen diverse chickpea germplasm accessions for drought tolerance and seed yield (ICC 67, ICC 867, ICC 898, ICC 3325, ICC 3776, ICC 4958, ICC 7184, ICC 7272, ICC 7323, ICC 8058, ICC 14199, ICC 14402, ICC 14778, ICC 14799, ICC 16796 and Annigeri) were used in this study. The thermal images of plant canopies were captured at 70 days after sowing by an infrared camera between 14.00 and 14.30 h. As maximum plant height of chickpea was approximately 40 cm, the top view of the thermal images were captured. The modified thermal images were analysed to compute the ratio of plant canopy area occupied by each colour to the total plant canopy area. Results showed that most of the canopy areas had either exhibited relatively hot (RH) or relatively cool (RC) temperature ranges. The significant differences among genotypes were also observed for the areas with RH or RC. The rest of the temperature regimes occupied insignificant proportions and with insignificant genotypic differences. The 16 entries were ranked based on the RC spectrum. ICC 7323 showed the smallest RC area in the plant canopy among all the entries, while ICC 14799 showed the largest. However, ICC 4958, a well-known chickpea genotype with more prolific and deeper root system throughout its growth period, stood fourth largest in RC area among the entries, which was due to better control of stomatal conductance. There was a significant positive correlation between the RC area and seed yield under rainfed conditions

publication date

  • 2008