Growth indices of wheat (Triticum aestivum L.) as influenced by thermal stress management strategies under late sown conditions.

摘要

An investigation was conducted at Research Farm, Department of Agricultural Meteorology, CCSHAU, Hisar located at 29 degrees 10'N latitude, 75 degrees 46'E longitude and 215.2 m altitude during rabi seasons of 2007-08 and 2008-09 (Last week of December) to study the growth indices of wheat as influenced by thermal stress management strategies under late sown conditions. Among pre-sowing strategies, the highest value of LAI was 4.70 in 2007-09 and 4.61 in 2008-09 in the treatment T₅. The peak LAD was observed at 71-90 DAS in all the treatments during both the years. The highest LAD was recorded in T₅ and the lowest was recorded in T₁ during both the years. The highest SLA was recorded in T₄ and the lowest was recorded in T₂ during both the crop seasons. The CGR was significantly higher in T₅ than other treatments except at 51-70 DAS where it was non-significant during 2007-08 and 2008-09. In the post-anthesis strategies, LAI and LAD were non-significant among treatments from 30 to 90 DAS and 90 DAS, respectively, and these were significant up to 111 and 91-110 DAS, respectively, during both the crop seasons. The SLA was non-significant among all the treatments from 30 to 90 DAS then it was significant at 110 DAS during both the crop seasons and it was lower in S₃ treatment. The highest CGR was observed in S₃ at 71-90 DAS as compared to other treatment during both the crop seasons. The growth indices like LAI and LAD were highly correlated with weather parameters at vegetative phase than reproductive phase, whereas SLA and CGR were highly associated at reproductive than vegetative phase.