Altering microclimate of wheat (Triticum aestivum L.) by adjusting sowing dates, irrigation and nitrogen application in semi-arid and arid agroclimatic conditions of Punjab

Abstract

Field experiments were conducted during rabi seasons of 2017-18 and 2018-19 and results of both the years were pooled to evaluate the microclimate of wheat under five dates of sowing, two nitrogen and two irrigation levels at Ludhiana and Bathinda representing semi-arid and arid agroclimatic regions of Punjab. Soil temperature reported during seed emergence was maximum in early sown (20th October) crop and decreased with delay in sowing at both the locations under study. Canopy temperature from 60 DAS onwards was recorded lower in 5th November and higher in 20th December sown crop while in case of irrigation and nitrogen levels, it was lower under optimal irrigation (I1) and recommended nitrogen (N1) application. Stress degree days (SDD) calculated were also lowest in 5th November sown crop (-323.6oC) and these were lower in N1 (-271.3oC) and I1 (-274.9oC) during both the years, respectively. Better crop growth and hence, leaf area index resulted in higher PAR interception in October sown with optimal irrigation and recommended nitrogen level. Canopy temperature at different periodic intervals (75, 90, 105 and 120 DAS) showed negative correlation with grain yield (R2 = 0.76, 0.75, 0.71 and 0.70, respectively). Similarly, SDD had negative relation with wheat yield (R2 = 0.74).

Keywords

• Wheat
• microclimate
• date of sowing
• irrigation
• nitrogen