INFLUENCE OF SOIL TREATMENT AND MEASUREMENTS OF WEED CONTROL FOR FORMING GRAIN PRODUCTIVITY OF SUGAR SORGHUM IN A LEFT-BANK FOREST-STEPPE

Abstract

Changes in climatic conditions prompted the study of the possibility of expanding the range of cultivating sugar sorghum. Therefore, the purpose of our research was to identify the peculiarities of the growth, development and formation of grain productivity of Sudanese sorghum and sugar sorghum depending on the basic cultivation of the soil and protection of plants from weeds in the conditions of the Left-Bank Forest-steppe.

In the process of research systems of basic soil cultivation were studied: generally accepted system – including soil scuffling, plowing and field leveling, and minimal system – where the plowing operation was missed. We also studied methods of weeds controlling: chemical – seed treatment with antidote Concept III 960 EC, application of soil herbicide before sowing Prymextra Gold 720 SC - 3-3,5 l/ha, mechanized – row spacing and combined – application of chemical protection and inter-row cultivation .

Field research was carried out at SFG "Rozdobudko MI" in the Pereyaslav-Khmelnitsky rayon of the Kyiv region, located in the Left-Bank Forest Steppe. The soil of this farm – typical chernozem, medium loamy with humus content – 3.32% (according to Tyurin methodic); nitrogen – 15.1 mg-eq /100 g soil (for Cornfield methodic), mobile phosphorus – 12.8 mg-eq/100 g soil (according to Chirikov methodic) and exchangeable potassium 10.4 mg- eq/100 g soil per 100 g the soil (according to Chirikov methodic). It is characterized by pH of salt water extract of soil – 5.6; hydrolytic acidity – 1.28 mg-eq/100 g of soil (according to Kappen methodic); the amount of absorbed alkalis is – 15.8 mg-eq/100 g of soil.

Phenological observations were carried out according to the methodology of the State Variety Trials of Agricultural Crops. Harvesting was done by continuous mowing and weighing of green mass. The dry matter content of the grass was determined by drying the green mass at a temperature of 105 ˚С. The yield of feed units and digestible protein was determined according to the chemical composition and according to the norms of the calculation of feed nutrition in feed units and the exchange energy. The processing of the obtained data was carried out using mathematical methods of analysis.

It was found that on chernozem typical Left-bank Forest-steppe plowing for basic soil cultivation creates better conditions for the development of the root system, plant resistance to adverse abiotic factors, and intensive growth of the plant top. The differences on linear growth of plants were 3-6 cm, for the density of agrocenoses – 2-13%, for the leafiness – 9-22% on average over the years of research.

A weed causes competition for sorghum in the early stages of development for important life factors. With aim of reducing the weed competition various methods of protecting of sorghum plants were carried out. Agrocenoses with weed control by the height of plants overcome control variants on 10-24 cm. The use of herbicides led to a raised in the density of the cenosis by 26-39%, mechanized propagation of row spacing – by 33-64%. The combination of chemical protection with mechanized increased densities of cenosis by 46-71%.

Between the studied species of sorghum were observed differences in the development of plants too. Sudanese sorghum was characterized by the highest shoot-forming capacity. The difference in the number of stems was – 15-30%. The sugar sorghum was more tall than Sudanese and was characterized by greater leafiness.

Formation of grain productivity of species of sorghum occurred in accordance with the regularities that were noted in the process of growth and development of plants.

Application of chemical protection of plants provides an increase in grain yield of 8-24%, inter-row cultivation – 24-33%. Combined employment of these elements of technology were increased the yield on 29-41%. The generally accepted soil cultivation system is overcome a minimal cultivation system on yield of grain on 2-9%.

Conventional soil cultivation system and combined plant protection from weeds the most effective combination. Holding a plowing provides the cultivation of a deeper layer of soil, promotes better penetration of moisture, air and more intensive development of the root system. Processing by herbicides contributes to the destruction of weeds in the initial stages of development and mechanized cultivation of row spacing serves both for the destruction of weeds and loosening of soil. For the period of ripeness the agrocoenosis of the sorghum were characterized by a plant height of 272-276 cm, a density of 185-159 pcs/m², and a leafiness of 24-28%. The yield of grain of Sudan sorghum is 5.09 t/ha, fodder units – 5.9 t/ha, digestible protein – 0.49 t/ha, output of exchange energy – 56.7 GJ/ha. The same parameters of sugar sorghum were 5, 42, 6.29, 0.53 t/ha and 60.3 GJ/ha accordingly.