RESPONSE OF WHEAT GENOTYPES TO DIFFERENT SOWING TIMES IN RELATION TO THERMAL ENVIRONMENTS IN HARYANA

Field study was carried out during the Rabi season of 2017-18 and 2018-19 at CCS Haryana Agricultural University, Hisar (Lat. 29 degrees 10' N, Log. 75 degrees 46' E and 215.2 m amsl) to investigate the effect of different environments on wheat genotypes. The experiment was laid out in split plot design with three sowing dates viz. 5th November, 15th December and 5th January in main plot and eight genotypes of wheat viz. HD 3226, HD 3059, DBW 71, DBW 173, PBW 752, HD 3086, PBW 757 and WR 544 in subplots, replicated thrice. On the basis of two years pooled data, it was revealed that wheat crop sown on 5th November took maximum calendar days (147.58 days), GDD (1805 C-0 day), HTU (100820 days hour), PTU (199660 days hour), Tp (3051.1 degrees C) and Tn (1832.8 degrees C) upto physiological maturity, which reduced significantly under 15th December and 5th January sowings. Yield attributes and grain yield were also higherin 5th November sowing, which were significantly higher as compared to 15th December and 5th January sowings. Crop sown on 5th November possess highest grain yield (58.72 q/ha), which was significantly higher than 15th December (47.29 q/ha) and 5th January sown crop (40.06 q/ha), mainly due to maximum number of effective tillers/m(2) (427.71), grains/earhead (49.51) and 1000 grain weight (41.55g) in 5th November sown crop. The reduction in grain yield was 19.47 and 31.78 percent by delayed sowing on 15th December and 5th January, respectively as compared to 5th November sowing. Among different genotypes, HD 3226 took maximum days to maturity (124 days) and GDD (1605.8 degrees C days). However, PBW 752 produced significantly higher grain yield (52.71 q/ha) as compared to other genotypes except HD 3086 (51.96 q/ha) and DBW 173 (51.06 q/ha), which was mainly due to maximum number of effective tillers/m(2) in PBW 752 (419.5). Whereas, minimum grain yield (39.66 q/ha) was recorded in WR 544. The grain yield and biological yield were highly correlated with the accumulated GDD (0.89**, 0.93**), PTU (0.90**, 0.94**), HTU (0.81**, 0.87**) Tp (0.93**, 0.97**) and Tn (0.92**, 0.95**) clearly suggesting thereby the significant effect of these indices on the wheat crop.