study effect of foliar application of iron and zinc on yield and yield components of autumn rapeseed (brassica napus l.) under limited irrigation

in order to study effect of foliar application of iron and zinc on yield and yield components of autumn rapeseed (brassica napus l.) under limited irrigation an experiment was conducted at research farm of agricultural faculty of urmia university in 2009. the experiment was designed in split plot based on randomized complete block design with 3 replications. treatments were drought (irrigation at all stages of growth, lack of irrigation at shooting stage, lack of irrigation at flowering stage, lack of irrigation at pod formation stage, lack of irrigation at grain filling stage) in main plots and foliar application (no foliar application, foliar application of iron sulfate (4 g/l), foliar application of zinc sulfate (4 g l-1)) in sub plots. no irrigation and no spraying at flowering stage reduced the number of seeds per pod (16.851). foliar application of zinc sulfate had positive effect on the number of pods per plant (63.375). the highest grain weight (6.401) was obtained from the treatment combination of irrigation at all stages of growth and foliar application of iron that this showed no significant difference with no irrigation at stem and pod formation stages and foliar application of iron. the lowest grain yield (1.10) was obtained from treatment combination of no irrigation at flowering stage and no foliar application. the highest oil percentage (50.12) was obtained from treatment combination of irrigation at all stage of growing and foliar application of iron and the lowest percentage of oil (43.16) was achieved of non-irrigated plots at grain filling stage with no spraying. the highest protein content (28.800) was achieved from non-irrigated plots at grain filling stage.