Assessment of biological and economic efficiency of herbicides in sunflower crops

Abstract

Recently, the interest of farmers in the mustard, as a culture of great opportunities, has increased due to the agronomic and agro-ecological benefits of growing it. The purpose of the research was to study the influence of doses of mineral fertilizers on different seed rates on the productivity of Sarepta and white mustard. The experiment was carried out in 2015-2017 in the experimental field of the Institute of Oilseed Crops. Four seeding rate were studied: 1,5; 2,0; 2,5; 3,0 million germinating seeds per hectare. Mineral fertilisers have been applied in the following doses: N50; P60; N50P60; N75P90; N100P120 with presowing cultivation. The study included two varieties of mustard: leaf mustard Prima and white mustard Zaporizhanka. Based on the results of three years of research, the effect of additional mineral nutrition on the indicators of the elements of productivity and yield of varieties of mustard yarrow for different seed rates has been established. The application of different doses of mineral fertilizers has led to an increase in relation to the control of the performance indicators of the mustard element of the spring Sarept variety Prima: the number of pods from 27,0-37,6 to 24,0-42,8 pc. and seeds from 224.3-379.5 to 226.9-442.5 pcs. on one plant, the weight of seeds from one plant from 0,527-0,976 to 0,553-1,302 g and a mass of 1000 seeds from 2,39-2,62 to 2,47-3,03 g. A similar trend was observed in relation to the characteristics of the mustard of the white-seeded white Zaporizhanka: number of pods from 24,0-38,1 to 24,2-45,4 pcs. and seeds from 105,0-172,5 to 108,1-214,8 pc. on one plant, the weight of seeds from one plant from 0,458-0,818 to 0,491-1,152 g and a weight of 1000 seeds with 4,41-4,76 to 4,55-5,40 g. In turn, an increase in the seed rate from 1.5 to 3.0 million pounds per hectare led to a decrease in these indicators. Greater indices of the number of pods and seeds per plant, both in the Prima variety and in the Zaporizhanka variety, are marked by the combined introduction of nitrogen and phosphorus. The largest weight of seeds per plant and the weight of 1000 seeds for the mustard Sarepts Prima variety – respectively 1,302 and 3,03 grams and for white mustard Zaporizhanka – 1,152 and 5,40 grams were obtained in the version with fertilization in a dose N100P120 with a seed rate of 1, 5 million pcs/ha. Analysis of the data on the growth and development of plants of the studied mustard varieties showed that, compared to the control in the fertilizer variant in the dose N100P120, the data increased in accordance with: in the prima variety 0,208-0,326 and 0,36-0,41 g; Zaporizhanka variety is 0,186-0,334 and 0,49-0,65 g. The level of yield, depending on the dose of fertilizers and seed rates, varied: in the prima variety from 1.15-1.76 t/ha; in the Zaporizhanka variety 1.04-1.64 t/ha. The highest yield, as in the Prima variety (1.63-1.76 t/ha), and in the Zaporizhanka variety (1.48-1.64 t/ha) was formed for the introduction of mineral fertilizers in a dose of N100P120. The yield increase in relation to control, depending on the seed rate, was 0.44-0.48 t/ha and 0.44-0.46 t/ha, respectively. The optimum seed rate for the Prima variety, which yielded the highest yield – 1.76 t/ha, was 2.0 million similar seed per hectare, and for Zaporizhanka with a yield of 1.64 t/ha – 2.5 million similar seed per hectare. On average, over three years of research, the content of fat in the mustard seed of the Sarept variety of Prima was within the range: 41.8- 42.2 % in control; in variants with the introduction of mineral fertilizers 41.9-42.4 %, and white mustard Zaporizhanka respectively: 30.0-30.3 % and 29.9-30.7 %. That indicates a rather insignificant influence of the factors studied on this indicator. Taking into account the yield, the maximum yield of oil per hectare for the Prima variety is 655 kg and for the Zaporizhanka variety 429 kg, obtained under the same conditions as yields. Among the agro methods that were studied for the crop formation, the use of mineral fertilizers (r = 0.85) and the poorly cultivar and the seeding rate r = -0.29 and r = -0.06 influenced the use of mineral fertilizers. The content of fats in the seed depended only on the variety r = -0.99. The yield of oil strongly correlated with the grade r = -0,84 and moderate with mineral fertilizers r = -0,47. It should be noted the average yield of the crop with the number of pods r = 0,34 and seed per plant r = 0,45 and the weight of the seeds from one plant r = 0,57.