Effects of different amounts of nitrogen, potassium and zinc fertilizers on yield, nitrate, zn contents and growth indices of common bean (Phaseolus vulgaris L.) cv. Sunray

To optimize the use of fertilizer on nitrate contents and yield of common bean cv. Sunray, an experiment was conducted in research farm of Agricultural College of Varaminin 2010, using a splite polot design based on RCBD with three teplications. The main plots were three Urea fertilizer levels 1) 250 kgha -1,2) 300 kgha -1 and 3) 350kgha -1, and sub plots were three K and Zn fertilizer combinations 1) 120 kgha -1 k,2) foliar spraying of 6/100 Zn and 3) 120 kgha -1K+6/1000 Zn. The hight nitratr content in bean pods was detected in treatment of 350 kghh –a Sulfur coated urea + 120 kgh -1 a k and the lowest nitrate content in treatment of 250 kgh -1 a urea + 120 kgh -1 a k + Zn spraying. The highest zn content of seeds was obtained from treatment of 250 kgh -1 a urea + k and Zn fertilizers. The highest pod and yield was also obtained from the latest treatment whereas the lowest yield belonged to the treatment of 350 kgh -1 a urea + 120 kgh -1 a k. The highest CGR in R5 growth period (22086 gm-2) was measured in 250 kgh-1 a urea and the lowest in 350 kgh-1 a urea treatments, respectively. Consumption of K and Zn spray had the highest CGR in P5 period (25.36 gm-2 perday). The highest NAR was recorded in V1 period (26.37 gm-2 per day) in treatment of 250 kgh –a urea while consumption of 350 kgh-1 a urea had the lowest NAR.