Thermal Indices of Fodder Cowpea (Vigna unguiculata (L.) Walp.) Cultivars in Bundelkhand Region of Central India

The present study was conducted to identify the impact of temperature indices on different phenophases and yield of cowpea varieties growing in Jhansi region of Uttar Pradesh, India. The cowpea (Vigna unguiculata L.) is a warm season legume crop grown in arid and semi-arid regions of India. Traditionally, it is very important as a staple food and source of fodder for the African continent, India and other semi-arid regions. A field experiment was conducted during rainyseasons (July to October) of 2010 and 2011 to determine the thermal indices for fodder cowpea varieties at Central Research Farm, ICAR-IGFRI, Jhansi. All the data were subjected to ANOVA using PROC GLM procedure in SAS (v 9.3). In ANOVA, varieties, date of sowing and year effect is considered as fixed factors and replication as random factor. Crop sown on 12th July took higher accumulated growing degree days (GDD) during 50% flowering (1111°C days) and maturity (2074°C days) as compared to crop sown during 4th August. Green fodder yield of Kohinoor recorded highest heat use efficiency (HUE) (32.4 kg ha-1°C day-1) over BL-2 and EC-4216 at the time of 50% flowering while it is at par with BL-1. From the results, it is found that early sownfodder cowpea recorded maximum duration, heat unit and heat use efficiency at maturity. The Variety Kohinoor recorded the highest grain yield, lowest calendar days and highest HUE as compared to all other varieties.