A field experiment was conducted at Institute of Agriculture and Animal Science (IAAS), Bhairahawa during winter season of 2019/2020 to find out the performance of wheat genotypes under timely sown (November 29, 2019) and late sown (December 25, 2019) conditions. The research was carried out in two environments (timely sown and late sown) following alpha lattice design with two replications. Each replication consists of five blocks with four plots in each block. The results revealed that all genotypes performance was decreased in late sowing environment. In late sown condition, there was significant difference among genotypes for all the traits under study and under timely sown condition, there was significant difference among genotype for all traits under study except weight of grains per spike and grain yield. The maximum yield was recorded in NL 1179 and Bhirkuti in timely and late sown conditions respectively. It was found that the mean grain yield in timely sown condition is 90.77 % higher than in late sown condition. The maximum grain yield was recorded in NL 1179 across combine environment. Int. J. Appl. Sci. Biotechnol. Vol 8(2): 161-169

The field experiment was carried out during winter of 2018/19 with two varieties (Unnati and Surkhet-Local) and three plant geometry (15cm × 10 cm, 30cm × 10 cm, 45cm × 10cm) in Randomized complete block design (RCBD) with four replications. Statistically there was no difference between two varieties while differences were found on different spacing and interaction between variety and spacing on final seed yield. High significant differences on seed yield was due to spacing and yield of rapeseed were higher at the 30 cm inter row spacing as compared to the 15 cm and 45 cm inter row spacing. Statistically significant effect was found on mean values of seed yield for interaction which showed that Unnati cultivar in 30 cm x 10 cm plant geometry had the highest seed yield (969.86 kg/ha) followed by Surkhet-local with  spacing of 15 cm × 10 cm (843.75 kg/ha) and 30 cm × 10 cm (823.76 kg/ha). Yield of these varieties decreased as spacing is increased, thus sowing of Unnati should be done at cropping geometry of 30 cm × 10 cm and for Surkhet-local it should not be done beyond 30 cm inter row spacing to get the maximum potential yield. Int. J. Appl. Sci. Biotechnol. Vol 9(2): 113-121.