Assay of sunflower genotypes productivity depending on some elements of cultivation technology on black soils of the Western Ciscaucasia

Influence of before-sowing application of fertilizers (N60P60 under before-sowing cultivation) at the different seed sowing rates (plant population 40, 60 and 80 ths. plants per ha) on sunflower genotypes productivity (early variety Buzuluk and middle variety Master, middle hybrid Alians Trio having the different duration of vegetative period) was studied in conditions of unstable moistening on leached (Krasnodar) and typical (Korenovsk district, Krasnodar region) chernozems in 2012-2014. The research showed the used method - N60P60 application under before-sowing cultivation - did not promote totally increasing of sunflower productivity on the different chernozem types (leached and typical) of the south of Russia; it depended mostly of a genotype and seed sowing rate. Seed yield of the varieties and hybrid did not depend on the fertilizer application and was similar: in Krasnodar - 2.57-2.59 t per ha, in Korenovsk district - 2.74-2.76 t per ha. Therefore, N60P60 application under before-sowing cultivation is not rational under sunflower. Enlarging of sowing rate from 40 to 60 and 80 ths seeds per ha caused decreasing of seed yield on 0.05-0.28 t per ha. Totally in trial, maximal yield was recorded for the hybrid Alians Trio in control plot with sowing rate 60 ths seed per ha 2.87 t per ha on leached chernozem and with sowing rate 40 ths seeds per ha - 3.13 t per ha on typical one. Fertilizer application led to a small decrease of oil content in seeds of the varieties and hybrid, and enlarging of sowing rate, on the contrary, caused its increase. Increasing of plant population from 40 to 80 ths per ha promoted enlarging oil content in seeds on 0.3-1.3%. Oil yield did not depend on fertilizer application and seed sowing rate. At the same time, at the increase of seed sowing rate up to 80 ths per ha there was noted a tendency of oil yield decrease, especially for the hybrid Alians Trio. Yield of the studied varieties a hybrid was on 0.17 t per ha higher at cultivation in Korenovsk district of Krasnodar region on typical chernozem in comparison to cultivation in Krasnodar on leached chernozem. It can be explained by a less water supply of plants in this place during vegetative period of the crop and high average daily air temperatures during sunflower flowering and ripening.