Effect of foliar application of flourish microcombi complex fertilizer and plant density on yield and some quantitative traits of promising sunflower cultivars

Sunflower belongs to the Astraea family and is one of the three important oil plants in the world, it has a high percentage of achene oil (45-50%). One of the main reasons for the low sunflower achene yield, is the lack of micronutrient elements. Thereforestrengthen, maintain productivity and determine the most appropriate crop density, in the new sunflower cultivars is necessary to achieve the desired yield. The present experiment was also performed basis on the selection of the most suitable promising sunflower cultivars in the best plant density and application levels of complex fertilizer flourish microcombi in Dezful city.

In order evaluation of yield and some quantitative traits of promising sunflower cultivars to foliar application of microcombi complex fertilizer and interaspecific competition, An split split plot experiment in a randomized complete blocks design with three replications and three factors density as the main factor (7, 9, 11 and 13 plant/m2), complex fertilizeras the first sub-factor (0, 1 and 2 kg/ha) from the source of complex fertilizer flourish microcombi produced by Shimikord company and cultivar as a second sub-factor (Felix, Shakira, Oscar, Savana, Shams, Labad, Sudimance, Monaliza) carried out in the crop year 2018-2019 at Dezful Shahid Rajaei Company. The seeds of the tested cultivars were prepared from Shahid Rajaei Dezful Company. Each experimental plot was considered with 6 planting line to length of 1.5 m with a lines spacing of 75 cm and according to the density of 7, 9, 11 and 13 plant/m2, the plants were arranged on planting lines at intervals of 18, 15, 12 and 9 cm in the three to four leaf stage, respectively. After physiological maturation of achenes and harvesting of plants, traits stem height, stem diameter, head diameter, number of achene/head, achenes of weight/head; achene yield and oil yield were measured.

The results showed a significant effect of foliar application of complex fertilizeras and density on the studied traits except stem height. Shams cultivar with 198.36 cm, had the maximum stem height. According to the results, foliar application of complex fertilizeras causes increases the stem diameter, number of achene/head, achenes of weight/head and achene and oil yield (t/ha) relative to the control. Also increasing planting density, despite reducing the number and weight of achene/head, increased achene yield. With increasing density, achene yield of single plant decreased, but increasing the number of plants per unit area compensated for this decrease. According to investigation the results of comparing the means, foliar application of complex fertilizeras by improving yield components and reducing competitive stress between plants at high planting densities, cause increase achene yield in sunflower. The maximum achene and oil yield were obtained to 5.40 and 2.64 t/ha, respectively, in the density 11 plant/m2 and foliar application 1 kg/ha complex fertilizeras by Felix cultivar. The increase yield in the density of 11 plant/m2, can be the result of sunflower adaptation by increasing the plant density and shows the achene yield has changed relatively little. Oil yield depend to achene yield and oil percentage, therefore, it seems that in the present experiment, higher achene yield in the density of 11 plant/m2 and improved photosynthesis and proper achene production in the time foliar application of complex fertilizeras, caused to increase oil yield.

Now with aware of the response of cultivars at different plant densities per unit area; it seems that the beneficial effect of foliar application of complex fertilizeras can cause reduce the damage by intraspecific competition and increase the yield of different sunflower genotypes in conditions of Dezful city and similar regions.