The effect of various amounts of humic chelate magnesium and gibberellic acid on yield and yield components of cowpea

The present study intended to investigate the effect of different doses of Humic Magnesium Chelate and Gibberellin on cowpea’s growth trend and production components under field conditions in Shadegan in Summer 2014. To this end, a factorial experiment in a randomized complete block design with three replications was conducted. The first factor included Humic Magnesium Chelate at three levels (0, 200 & 400 ml.h) and the second factor included Gibberellin at three levels (0, 150 & 300 ppm). Results of variance analysis showed that interaction between humic acid and gibberellic acid on number of pods per plant, seeds per pod, seed weight and biological yield was significant at %5 level, grain yield and harvest index was significant at %1 level. the highest grain yield was associated with the treatment of Humic Magnesium Chelate 200 ml.h and Gibberellin 150 ppm by 2.720 kg.ha; on the contrary, The lowest grain yield was observed in the control treatment by 1,950 kg.ha. Besides, the highest HI belonged to the treatment of Humic Magnesium Chelate 200 ml.h and Gibberellin 150 ppm by %40 while the lowest HI was related to the treatment of Humic Magnesium Chelate 400 ml.h and Gibberellin 300 ppm by %28. To conclude, the results of the current research showed that the effect of Gibberellin treatment was higher on different doses of measured traits than Humic Magnesium Chelate treatment; and the application of Humic Magnesium Chelate 200 ml.h and Gibberellin 150 ppm was more effective on grain yield, yield components in comparison to the consumption of the higher concentration doses.