Yield attributes and quality of cowpea as influenced by nitrogen and phosphorus levels on medium black soil of Gujarat

SUMMARY A field experiment was conducted during 2012 to study the yield attributes and quality of cowpea (GC-5) as influenced by nitrogen and phosphorus levels on medium black soil of Gujarat. The experiment consisted of four treatments of nitrogen levels (control, 20, 30 and 40 kg/ha) and four treatments of phosphorus levels (control, 40, 60 and 80 kg P 2 O 5 /ha) thereby making 16 treatment combinations tested in factorial randomized block design with three replications. The results indicated that the application of nitrogen @ 40 kg/ha gave the maximum and significantly higher number of pods per plant, number of seeds per pod, test weight, seed yield, straw yield, biological yield, protein content, chlorophyll content and remained at par with 20 and 30 kg N/ha over control. The maximum net returns and BCR were found with the application of 20 kg N/ha. Results further indicated that the application of phosphorus @ 80 kg/ ha gave the maximum and significantly higher number of pods per plant, number of seeds per pod, test weight, seed, straw, biological yields, protein content, chlorophyll content and remained at par with 40 and 60 kg P 2 O 5 /ha over control. The maximum net returns and BCR were found with the application of 40 kg P 2 O 5 /ha. The combined application of nitrogen and phosphorus levels @ 20 and 40 kg P 2 O 5 /ha was significantly higher in terms of seed and straw yield over rest of the treatments.