Phenology, thermal indices and yield of chickpea (Cicer arietinum L.) varieties under different sowing dates in New Alluvial Zone of West Bengal

A field experiment was conducted at Instructional Farm of Bidhan Chandra Krishi Viswavidyalaya, Jaguli, Nadia, West Bengal, India to study the effect of four sowing dates and four varieties on phenology and yield of chickpea during rabi season of 2017-18. Mean cultivar days of chickpea crop from sowing to emergence, flower initiation, pod initiation and maturity were 6.7, 59.6, 80.5 and 112.6 days, respectively. The duration of chickpea and summed growing degree days (GDD) were reduced successively with delay in sowing from 4 November (119.8 days and 1715) to 19 December (103.9 days and 1604). The average GDD, heliothermal units (HTU) and photothermal units (PTU) for entire life cycle of chickpea were recorded as 1661, 11403 and 18766, respectively. Chickpea sown on 20 November produced the highest seed yield (1084.50 kg/ha), which was 11.4, 16.9 and 34.7% greater over 4 November, 5 December and 19 December, respectively. The correlations between thermal indices and seed yield revealed that GDD (r = 0.483**), HTU (r = 0.633**) and PTU (r = 0.379**) during pod initiation to maturity had positive effect (P < 0.01) on economic yield of chickpea. Based on seed yield, chickpea varieties could be arranged as ‘Uday’ (1058 kg/ha) > ‘JG 14’ (908 kg/ha) > ‘Anuradha’ (904 kg/ha) > ‘Vaibhav’ (787 kg/ha).