Assessing the Impact of Thermal Units on Growth and Development of Summer Pearl Millet under Different Sowing Times and Irrigation Regimes

Abstract

At present in the context of climate change, temperature is one of the most important environmental factors influencing the pearl millet crop growth, development and yield. The objective of this study is to provide an overview of the influence of sowing times and irrigation regimes and temperature on pearl millet accumulated growing degree days, helio thermal units and stress degree days. A field experiment was conducted during 2010 and 2011 at Water Management Farm,[21] Mahatma Phule Krishi Vidyapeeth, Rahuri (Maharashtra, India). The experiment was laid out in strip plot design with three replications consisted of four sowing times viz., D₁-6^th MW (5-11 February), D₂-8^th MW (19-25 February), D₃-10^th MW (5-11 March) and D₄-12^th MW (19-25 March) and three irrigation regimes, viz., I₁-100 mm CPE, I₂-125 mm CPE and I₃-150 mm CPE. The results revealed that accumulation growing degree days and helio thermal units during sowing to maturity decreased with successive delay in sowing and later irrigation regime while, in case of stress degree days during sowing to maturity decreased with successive delay in sowing and former irrigation regime. The highest grain yield is from the treatment 8^th MW week with 30.09 q ha^-1 followed by 28.50 q ha^-1 under 6^th MW and 26.76 q ha^-1 at 10^th MW sown crop. The yield loss under 12^th MW (25.39 q ha^-1) sown crop is due to the sterile florets and lesser crop duration.