Influence of sowing time on phenology, thermal indices and yield of field pea varieties (Pisum sativum L.) in Gangetic delta of West Bengal

The effect of two sowing dates on phenology, growth and yield of four field pea varieties was studied during rabi season of 2021–22. The average phenophase duration from sowing to >50% emergence, >50% emergence to >10% flowering, and >10% flowering to >10% podding were 6.2, 47.9 and 9.1 days, respectively. Mean summed GDD and PTU for fieldpea varieties at different phenophases were 122.1°C day and 1356.4°C hour (sowing to >50% emergence), 822.5°C day and 9359.4°C hour (>50% emergence to >10% flowering) and, 154.5°C day and 1481.1°C hour (>10% flowering to >10% podding). Genetic variation among the four varieties was noted in number of branches/plant (11.7–16.5), pod length (5.2–6.1 cm), number of seeds/pod (2.7–3.8) and 1000 seed weight (159.4–168.3 g), except protein content. Field pea sown on 24 November produced higher grain yield (785.5 kg/ha) due to significant improvement in plant population (35.3 plants/m²) and 1000 grain weight (169.6 g), and that yield was 5.9% greater over early November sowing. Based on yield performance, it can be concluded that IPFD 6–3 recorded the highest yield (818.0 kg/ha) followed by IPFD 12-2 (787.5 kg/ha).