Evaluation of growth indices and quantitative traits of safflower under organic farming and conventional agriculture

Application of organic fertilizers in sustainable agriculture systems improves yield sustainability of field crop production. The current research has been formed to investigate the effects of various levels of vermicompost (zero, 3, 6 and 9 t ha^?1) in combination with foliar spraying of potassium humate (0, 1, 2 and 3 mL L^?1) on spring safflower, in Iran during 2012–2013. In addition, inorganic fertilization has been considered as conventional agriculture (CA). In the current experiment, growth indices, seed yield, yield components and flower yield were evaluated. The results showed that the maximum leaf area index, total dry weight and crop growth rate have been determined at 9 t ha^?1 vermicompost and 3 mL L^?1 K-humate while the maximum netto assimilation rate has existed in CA at the emergence of flower buds. Likewise, the results indicated that vermicompost leads to a significant increase in seed yield, flower yield and yield components except 1000 seed weight. Flower yield, head number per plant and seed number per head were affected by K-humate concentrations and increased significantly from 1 to 3 mL L^?1. It should be mentioned that 9 t ha^?1 vermicompost and 3 mL L^?1 K-humate produced the highest seed and flower yield.