The effect of growth regulators and mineral fertilizers on corn productivity in the chernozem of Rostov region

The research objective was the assessment of the efficiency of separate and combined use of traditional means of chemicalixation and growth regulators on the crops of the corn for grain in the conditions of Rostov Region. Field experiments were made on mid-early hybrid of the corn zoned in the region of Krasnodar 291 AMB in Azov area of Rostov Region. The soil of experimental site was ordinary chernozem carbonate hard loamy loessoid loam. Agrochemical characteristic of the soil was: humus content in arable layer - 3.11 %; pH of salt extract - 7.2; the gross content of nitrogen - 0.235 %; the content of mobile phosphorus - from 20.3 to 21.8 mg/kg; exchange potassium - from 285.3 to 305.6 mg/kg. Field experiment was two-factorial with allotments splitting. A factor included three options with mineral fertilizers: 1 - control (without fertilizers); 2 - sulphoammophos N50P50S20; 3 - azophoska N50P50K50. B factor included 7 options with growth regulators by means of processing of seeds (*) and single not root top dressing (**): 1 - control (without agrochemical); 2 - monokalyphosphate (1.0 kg/t* + 1.0 kg/hectare**); 3 - "Aquamix ST" (0,1 kg/t* + 0,5 kg/hectare**); 4 - "Extrasol" (1,0 l/t* + 1,0 l/hectare**); 5 - "Mizorin" (0,5 l/t* + 0,5 l/hectare**); 6 - "Rostock" (0,5 l/t* + 0,5 l/hectare**); 7 - "Boro-N" + chelate Zn + chelate Mn + magnysulphate (0,5 l/hectare** + 0,25 kg/hectare** + 0,25 kg/hectare** +1 kg/hectare**). As a result of the experiments positive influence of combined using of mineral fertilizers and growth regulators on the efficiency of the corn was found out. For 2 years the increase of the productivity of the corn for grain in comparison with control option averaged from 0.24 to 0.80 t/hectare. Using growth regulators "Aquamix ST", "Mizorin", "Extrasol" and "Rostock" was more effective in the influence on the productivity of the corn of traditional mineral fertilizers by 6-11 %. Maximum efficiency was shown by the combination pre-sowing application of azophoska N50P50K50 to seeds processing and not root top dressing of crops by the growth regulator "Mizorin": the increase of the productivity to the control made 27.0 %.