The dissertation is devoted to the development of elements of sweet potato cultivation technology for the conditions of the Left Bank Forest-Steppe of Ukraine, which contributes to the popularization and spread of a promising niche vegetable crop (in the modern consumer market, niche crops have a high margin).
Sweet potato is a fairly common crop in the world (tubers contain a large amount of potassium, antioxidants, vitamins A and C, group B, iron, phosphorus, calcium, magnesium), but there are no ready-made technological solutions for growing this crop in Ukraine's soil and climate conditions.
For the first time, the patterns of yield formation of sweet potato under different fertilization systems (mineral, organic, with a complex of microbial preparations) were revealed for the conditions of the Left Bank Forest-Steppe of Ukraine; the influence of macro- and microelements deficiency on the growth processes of sweet potato plants was investigated to form a database of visual signs of deficiency of various nutrients; the removal and consumption of basic nutrients by sweet potato plants, the coefficients of nutrient use from mineral fertilizers and soil were determined for the soil and climatic conditions of Ukraine; the allopathic effect of the main weeds of vegetable agrocenoses on the growth processes of sweet potato plants (acts as a fundamental basis for the formation of a system of crop protection against weeds); the allopathic effect of various crops (vegetable, fodder grasses) on the growth and development of sweet potato plants (it is the basis for the formation of polyculture agrocenoses with sweet potato and the basis for determining the optimal precursors for the crop) was determined;
The negative effect on the growth processes of sweet potato plants under the deficiency of nitrogen, phosphorus, potassium, iron and zinc was determined, which is confirmed by a significant decrease in plant biometric parameters (total plant length, number of leaves and internodes, length and width of the leaf plate, petiole length, presence of lateral shoots, total mass and mass of plant parts). There was no negative effect on the growth of sweet potato plants from boron deficiency (only plant length and number of leaves were significantly reduced).
It is noted that the use of mineral fertilizers N370P370K450 both separately and in a complex with foliar fertilizers Nutrivant Plus Universal" leads to the formation of a high supply of sweet potato plants with basic nutrients throughout the growing season.
When using the system of optimization of plant nutrition with the introduction of humus and ash, a similar pattern is observed in terms of the provision of the tilth layer of soil with mobile phosphorus and potassium compounds, but with the formation of an average level of supply of nitrogen compounds in the second decade of July and a high level of supply of this nutrient at the end of the vegetation of sweet potato plants.
The largest total plant weight is formed when using a mineral fertilizer system. Under the organic fertilizer system, the accumulation of average plant weight is slow in the initial periods of growth and accelerates at the end of the growing season, which, in our opinion, is due to the slow mineralization of organic matter of humus and the formation of an optimal soil nutrient regime in later periods of sweet potato plant development.
It has been proved that the use of mineral fertilizers leads to an active growth of vegetative and root mass, leaf area of sweet potato plants throughout the growing season, a significant increase in net photosynthetic productivity in the first half of the growing season (24.3 g/m2 per day). When using organic fertilizers, intensive development of plant roots in the second half of the growing season and inhibition of leaf-stem mass formation processes are observed; net photosynthetic productivity increases (57.7 g/m2 per day).
For the conditions of the Left Bank Forest Steppe of Ukraine, it is better to use N370P370K450 with foliar fertilization "Nutrivant Plus Universal" for intensive cultivation technologies according to yield parameters and quality composition of tubers for the Slobozhanskyi Rubin and Admiral varieties, for organic cultivation technologies – application of humus 20 t/ha, ash 1 t/ha and a complex of microbial preparations (Groundfix, Azotophyt, Organic balance, Help-rost for vegetables). In addition, there is an increase in yield by 4.7-5.9 t/ha or 32.0-40.1% for the Slobozhanskyi Rubin variety, and by 1.7-1.8 t/ha or 22.7-24.0% for the Admiral variety.
Improvement of a number of quality indicators of tubers of the Slobozhanskyi Rubin variety was noted with the use of humus 20 t/ha, ash 1 t/ha and a complex of microbial preparations (increased dry matter content to 17.25%, starch to 9.47%, reduced nitrate content to 28.5 mg/kg).
