Phenology and growth dynamics of groundnut (Arachis hypogaea L.) cultivars under different dates of sowing

Field experiments were conducted with groundnut crop on a sandy loam soil at the Research Farm, School of Climate change and Agricultural Meteorology, Punjab Agricultutal University, Ludhiana during three kharif seasons. The experiment evaluated the phenology and growth dynamics of two cultivars of groundnut (M-522 (V₁) and M-548 (V₂)) under three dates of sowing. The duration of crop growth reduced and dry matter accumulation also decreased with delay in sowing from June to July. Crop growth rate (CGR) was lower during initial crop growth stages and increased with crop growth and development. On the other hand, relative growth rate (RGR) was relatively higher during early growth of the crop and it decreased as the crop advanced towards maturity. Between the cultivars, highest CGR was observed in M-548 under all the dates of sowing and crop growing seasons. Among the dates of sowing, CGR was found highest in the 1^st June sown crop and lowest in the 20^th July sown crop. Whereas, RGR was highest in M-522 in the earliest sown crop and in M-548 under second and third date of sowing. Amongst the two cultivars, cv. M-548 attained maximum specific leaf weight during all the crop growing seasons. A significant reduction in maximum specific leaf weight was observed with delay in sowing.