Influence of Nitrogen Levels and Decapitation Stress on Biological Potential of Rapeseed (Brassica Napus L) under Water Difficit Condition of Swat-Pakistan

Abstract

An experiment entitled “production potential of rapeseed (Brassica napus L) as influenced by different nitrogen levels and decapitation stress under the rainfed agro-climatic condition of Swat-Pakistanwas conducted at Agriculture Research farm Matta (Swat) during Rabi season 2012-13. The field experiment was carried out in randomized complete block design (RCBD) having four replications. The sub plot size was kept 5m x 2.7m having 6 rows with 0.45 m apart. Four levels of nitrogen (0, 33, 66 and 100 kg ha^-1) and five levels of decapitation stress (no stress, 5, 10, 15 and 20 cm) were used in the experiment using cultivar Oscar. From the results it is observed that rapeseed cultivar positively responded for seeds pod^-1, thousand seed weight (g), biological yield (kg ha^-1), seed yield (kg ha^-1) and oil yield (kg ha^-1)to N levels and maximumseeds pod^-1 (23 seeds), thousand seed weight (3.59 g), biological yield (10310 kg ha^-1), seed yield (1169 kg ha^-1) and oil yield (600 kg ha^-1) was observed in plot treated with 100 kg N ha^-1. Whereas minimumseeds pod^-1 (15 seeds), thousand seed weight (2.41 g), biological yield (6725 kg ha^-1), seed yield (923 kg ha^-1) and oil yield (401 kg ha^-1) was recorded in control plot. Similarly highest seeds pod^-1(22),thousand seed weight (3.3 g), seed yield (1099 kg ha^-1) was noted in no decapitation stress inserted plot followed by 20 cm stress inserted plot while promising biological yield (9025 kg ha^-1), and oil yield (568 kg ha^-1) was recorded in 15 and 20 cm decapitation stress inserted plot. On the basis of the result it is concluded that decapitation stress with 100 kg N ha^-1 produced highest seed and oil yield with green chop and recommended for higher seed, oil and biological yield in the rainfed agro- climatic condition of swat valley.

Keywords: Rapeseed (Brassica napus L.), decapitation stress,yield, Oil, seeds pod^-1