Assessing the Variations in Canopy Temperature, Relative Humidity and Soil Temperature within the Canopy of Winter Maize in Bihar

Abstract

Variations in canopy temperature, relative humidity and soil temperature within crop micro-environment exert full control over plant’s physiological processes and thereby over growth, development and yield of crop. These micro-meteorological parameters tend to significantly control the exchange of energy between the crop environment and the atmosphere. Keeping all this in view, a field experiment with winter maize ( var. Rajendra hybrid 4) was conducted with five dates of sowing viz., 1 November (D1), 10 November (D2), 20 November (D3), 30 November (D4) and 10 December (D5) and three spacings viz., 60 X 20 cm (S1), 75 cm X 20 cm (S2) and 45 cm X 20 cm (S3) at the University farm of Dr Rajendra Prasad Central Agricultural University, Pusa, Samastipur, Bihar during rabi season of 2021-22 to assess the variations in canopy temperature, relative humidity and soil temperature, as influenced by micro-environments and planting density. The experiment was laid out in split plot design with sowing dates as main-plots and spacings as split plots. Results revealed that canopy temperature was found to be the highest for the crop planted on D4 (30 November) with S2 (75cm X 20 cm) spacing, while the lowest was associated with the crop sown on D1 (1 November) with S3 (45 cm X 20 cm) spacing. Mean canopy temperature decreased from sowing to knee high stage, thereafter it increased with every phenological stage up to physiological maturity. Crop sown on D3 (20 November) having S3 (45 cm X 20 cm) spacing recorded maximum relative humidity. Highest soil temperature at 15 cm depth was recorded for D5 (10 December) sown and S2 (75cm X 20cm) spaced crop and the lowest for D2 (10 November) having S3 (45cm X 20cm) spacing. Information generated on the variation in canopy temperature, relative humidity and soil temperature at different phenophases of winter maize would be useful in managing abiotic stresses on crop production.