The effect of water stress on changing Macro elements (N, P, K) inLeaf of Rapeseed genotypes (Brassica napus)

In order to study the effects of water stress on Macro elements (n, p, and k) on leaf Rapeseed genotypes an experiment was conducted in 2003-2004 in varamin, college of agriculture research field. This study was carried out in split plot arranged in randomized complete block design with four replications. The main plot consisted of water stress and non stress condition (0, 25 and 75 percent of Fc) and sub plots consisted of genotypes, Hyola - 42, Syn1, Pf 7045.01, Symbol and Mohican. Plant characters evaluated in this study were: Plant weight, number of pods per plant, number of grains per pod, 1000 grain weight, grain yield, percent oil content and yield of oil. Analysis of data showed significant differences between irrigation treatment and varieties in pods per plant, grains in pod and grain yield. Among varieties had been seen most yield and yield component observed in Hyola 42 (with 3377/5 Kg/ha) and lowest yield was seen in Symbol (with 1947 Kg/ha). 1000 grain weight and other characteristics were effected by water stress, so there were in water deficit (0 percent of Fc) treatment reduced than normal treatment. and showed significant difference between varieties in level 1% In split plot design, water stress Increased nitrogen concentration of 2/5% reached to a level of 3/7% of leaves in dry matter. But decreased Phosphor from a level of 0/35% to 0/18 % and Potassium from 2/73% reached to 1/09% in leave, dry matter. Water stress (75 percent to 0 percent of Fc) decreased Grain yield and Oil yield. Grain yield of (3340 Kg /ha) decreased to (1788 Kg/ha) and oil yield from (1343 kg/ha) to (753 kg/ha). Cultivars were not significantly in oil content. But water stress decreased oil content from (43/1% on 75% FC to 40/2% on 0% FC)In conclusion, differences is exist between Rapeseed cultivars and lines in response to water stress, and this may be due to different accumulation of compatible solutes, and physiological aspects example yield and yield component.