Temperature Use Efficiency and Yield of Groundnut Varieties in Response to Sowing Dates and Fertility Levels in Western Dry Zone of India

A field experiment was conducted in loamy sand soil during kharif season of 2009 and 2010 to evaluate the temperature use efficiency and yield of groundnut varieties in response sowing dates and fertility levels. The treatments consisted of four sowing dates (20 April, 15 May, 9 June and 4 July) and two varieties of groundnut (HNG 10 and TG 37A) as main-plot treatments and four fertility levels of nitrogen and phosphorus application (0, 20 N-40 P2O5, 30-60 P2O5 and 40 N-80 P2O5 kg ha-1 ) as sub-plot making a total of 32 treatment combinations. The experiment was laid out in split-plot design with three replications and crop growth rate, yield parameters, harvest index and temperature use efficiency were recorded on crop. The results showed that significantly higher crop growth rate (CGR) at 30-60 and 60-90 days after sowing (DAS) was observed in HNG 10 variety. Further delays in sowing from 9 June significantly reduce crop growth rate. However, the growth rate of TG 37A variety was observed to be statistically at par among the sowing dates. In HNG 10 variety higher pod yield (3773, 3743 and 3738 kg ha-1), kernel, haulm and biological yield were observed at par to each other from 20 April to 9 June sowing, respectively. Maximum heat unit efficiency (3.23 kg ha-1 degree- day-1) was observed on 9 June sowing date while the highest yield (2628 kg ha-1) was recorded in TG 37A variety with 4 July sowing. Harvest index in both the varieties was observed to be significantly higher in 4 July sowing date. All the fertility treatments produced significantly higher crop growth rate and yields than the treatments receiving no fertilizer application. Application of 30 kg N-60 kg P2O5 ha-1 significantly enhanced the crop growth and yield over 20 kg N-40 kg P2O5 ha-1 and control but at par with 40 kg N-80 kg P2O5 ha-1 . However, the crop uses maximum temperature in the month of June for better growth and yield. Thus, it could be concluded that the suitable sowing date of HNG 10 and TG 37A varieties in western dry zone of India are around 9 June and 4 July respectively. Application of 30 kg N-60 kg P2O5 ha-1 was optimum for growth and yield of the crop.