Agroclimatic Indices for Prediction of pod yield of Groundnut (Arachis hypogaea L.) in Punjab

Agroclimatic indices based on growing degree days (GDD), Heliothermal units (HTU), photothermal units (PTU) and Heat use efficiency (HUE) were evaluated for the prediction of growth and yield of groundnut crop. Field experiments were conducted during three consecutive kharif seasons of 2004, 2005 and 2006 at the research farm, Department of Agricultural Meteorology, Punjab Agricultural University, Ludhiana. Two cultivars of groundnut viz. M-522 (V₁) and M-548 (V₂) were grown under three dates of sowing viz. 1^st June (D₁), 20^th June (D₂) and 10^th July (D₃) during all the crop seasons. Dry matter accumulation and pod yield were correlated with the agroclimatic indices of GDD, HTU, PTU and HUE and significant regression relationships were observed between them. Such models can be used to estimate growth and yield of groundnut crop using information on daily temperature, photoperiod and sunshine duration during the crop growing season. Among the cultivars, heat use efficiency was found higher in M-522, which indicates that it can utilise heat more efficiently and can perform better under global warming scenarios.