عنوان مقاله [English]
Safflower (Carthamus tinctorius) is an annual crop with high environmental compatibility and resistant to drought condition. Vermi-compost is the ability of some species of earthworms to consume and break down a wide range of organic residues such as sewage sludge, animal wastes, crop residues and industrial refuse. Vermi-composts are usually more stable than their parent materials with increased availability of nutrients and improved physicochemical and microbiological properties. Aerial compost tea contains high populations of live microorganism consisting of rhizobactria, trichoderma and pseudomonas species which increase the growth and yield of the plant. Acid humic is the main humic substance and the important ingredient of soil organic matter (humus) which increase crop yield and quality. The aim of this study is evaluating potential use of vermi-compost as a biological fertilizer in safflower production and assessment of foliar application of compost tea and humic acid related to vermi-compost utilization in safflower production.
Material and Methods
In order to study the effect of vermi-compost and foliar application of compost tea and acid humic on growth indices of safflower (Carthamus tinctorius L.), an experiment was conducted as a factorial based on complete randomized design with three replications in agricultural research farm at Vali-e-Asr University of Rafsanjan. Treatments were included application of vermi-compost (0 (control), 4, 8 and 12 t.ha-1) and 4 level of foliar application (distilled water as control, acid humic derived from vermi-compost, commercial acid humic and compost tea). Samples collected from the center of each treatment plot with observance of margin effect. Samples were taken 30 days after planting which is collected 10 times over the growth stage every 10 days for determine of total dry weight, LAI change trend, CGR, NAR and RGR.
Results and Discussion
Results indicated that vermi-compost and foliar application treatment significantly affected LAI, CGR, NAR, TDM and RGR. Applying more vermi-compost resulted in higher CGR and NAR which is observed under 12 t.ha-1 vermi-compost and the lowest level of vermi-compost (control) resulted in 1145 GDD. The highest and the lowest LAI, CGR and NAR obtained under tea compost foliar application treatment and control, respectively. Under all treatments declining trend observed from 1145 GDD (first flower appearance). The highest total dry matter obtained under the 12 t.ha-1 vermi-compost at 1847 GDD and the maximum of RGR observed in early growth (277 GDD) in 12 t.ha-1 vermi-compost with foliar application of tea compost and then declined. It is also resulted that the highest seed yield obtained from 8 t.ha-1 vermi-compost with no significant difference with 12 t.ha-1 vermi-compost. Vermi-compost have available plant nutrient solution which increase leaf area indices compared with none use vermi-compost treatment. Hameeda et al. (2007) reported that using 10 t.ha-1 vermi-compost increased the leaf area of sorghum more than 34 % compared with control. Arancon et al. (2004) also reported that using 5 and 10 t.ha-1 vermi-compost significantly increased leaf area, shoot dry matter and RGR in strawberry. Vermi-comost due to containing micro and macro element, plant growth stimulate and hormones can improvement of physiological indices like LA, CGR and NAR and finally total dry weight. Vermi-compost have different enzyme like protease, lipase, amylase and cellules which decompose the soil organic matter and the plant remains and increase the plant availability of nutritional element.
Results indicated that using 12 t.ha-1 vermi-compost and foliar application of compost tea caused increasing of LAI, CGR, TDM, NAR and RGR compared with control. It is also resulted that using 8 and 12 t.ha-1 vermi-compost significantly increased safflower yield while no significant effect observed from foliar application. Totally, it is concluded that in Rafsanjan climate, using 12 t.ha-1 vermi-compost is the best treatment for increasing growth indices and seed yield of safflower.