Effect of Time of Sowing on the Performance of Soybean [Glycine max (L.) Merrill] in Punjab

The experiment was conducted at Punjab Agricultural University, Ludhiana (Punjab) during kharif 2008 and 2009 to study the effect of time of sowing on the performance of soybean. It was comprised of nine treatments with three sowing dates (June 5, June 15 and June 25) as main plot treatments and three genotypes of soybean (SL 525, SL 744 and SL 790) as sub plot treatments and replicated four times. The highest grain yield (2537 kg/ha) was recorded in June 5 sown crop which was significantly higher than June 25 sowing (2169 kg/ha) but statistically at par with June 15 sowing (2386 kg/ha) in 2008. In 2009 June 15 sowing (1811 kg/ha) recorded highest grain yield which was statistically on par with June 5 (1704 kg/ha) but significantly higher than June 25 sowing (1350 kg/ha). As the sowing date delayed, the thermal heat units were found to be reduced for 50% flowering and maturity. The variety SL 744 gave the highest grain yield, which was statistically at par with SL 790 but significantly higher than SL 525. The oil content was the highest in variety SL 525 which was statistically at par with SL 744 but significantly higher than SL 790.