Effect of humic acid fertilizer application and foliar spraying of compost tea and vermiwash on growth indices of safflower (Carthamus tinctorius L.)

Growth analysis is a valuable and practical method on quantitative growth, development and crop production evaluation. In order to study the effects of granular humic acid and foliar application of compost tea and vermiwash on growth indices of safflower (carthamus tinctorius), an experiment was conducted as a factorial based on randomized complete block design with three replications in agricultural research farm at Vali-e-Asr University of Rafsanjan in 2014. Treatments included of soil application of humic acid (0, 500, 1000 and 1500 kg.ha-1) and foliar spraying of vermiwash 1:10, vermiwash 1:20, compost tea and distilled water as control. The highest LAI (1.96), CGR (26.85 gr.m-2.day-1), TDW (1232 gr.m-2), NAR (12.94 gr.m-2.day-1) and RGR (0.13 gr.gr-1.day-1) obtained by using 1500 kg.ha-1 humic acid and the lowest of them (1.29, 15.81 gr.m-2.day-1, 671 gr.m-2, 8.98 gr.m-2.day-1 and 0.108 gr.gr-1.day-1) observed in control. It is also resulted that compost tea foliar application increased LAI, CGR, TDW, NAR and RGR. Totally, humic acid application (1500 kg.ha-1) in soil along with compost tea foliar application was the best treatment for getting higher growth indices and seed yield of safflower in order to achieved sustainable agriculture.