Evaluation Effect of Different Amount and Time of Apply Gibberellin Acid on Correlation between Trait, Regression Relationships and Grain Filling Rate of Broad Bean

BACKGROUND: Vicia faba L. is a major crop legume that is used as food owing to the high nutrient components in seeds. Development of high yielding and stable cultivars of various legume crops across different environments is very important for their adoption by farmers. OBJECTIVES: The current study was conducted to evaluate the effect of different amount and time of apply Gibberellin acid on correlation between characteristics and regression relationship between effective traits on seed yield of Broad bean. METHODS: This research was done via factorial experiment based on randomized complete blocks design with three replications along 2010 year. The treatments included different concentration of Gibberellin (nonuse of Gibberellin or control, 5 ppm, 50 ppm and 250 ppm) and time of application Gibberellin (Vegetative growth before flowering, flowering until pod emergence, Pod emergence until grain filing). RESULT: According result of analysis of variance effect of different Gibberline acid concentration at different growth stage and interaction effect of treatment on all measured traits was significant. Correlation between traits showed the significant correlation between total dry weight (r=0.97**), harvest index (r=0.94**), seed weight (r=0.90**), number of seed per pod (r= 0.85**), number of pod per plant (r= 0.81**), Pod length (r= 0.61**), leaf area index (r= 0.59**) and seed yield was observed. Grain filling rate changes in all three concentrations of gibberellin acid had an increasing trend. Gibberellin acid consumption in the period of vegetative growth compared to apply hormone at other growth stage had the highest grain filling rate. CONCLUSION: The highest grain filling rate achieved by use of 50 ppm Gibberellin acid at vegetative growth before flowering.