Efficiency of foliar application with Agrochelate organic fertilizer on seed plots of summer sowing watermelon

Relevance. In the central zone of the Krasnodar Territory, the mobility and availability of the main elements of mineral nutrition can be limited in certain phases of the growing season of melons and gourds, especially with a decrease in soil moisture and high temperatures. An important additional and corrective element of nutritional technology is foliar feeding, which increase the absorption of fertilizers during critical periods of plant growth and development. Material and methods. The purpose of the research is to determine the effectiveness of foliar application with organic fertilizer AGROCHELATE to maximize the biological potential of watermelon varieties on seed plots during summer sowing. The research was carried out at the seed-growing area of the vegetable growing department in the "Federal Scientific Rice Centre" in 2020-2021. The object of research was selected varieties of watermelon selection “Federal Scientific Rice Centre” Tersky early and Yubilyar with a growing season of 65-75 days. Organic fertilizer AGROCHELATE was used to treat the leaf surface of plants with a consumption rate of 100 ml/ha. A single spraying was used during the flowering phase of the plants. For the isolation of seeds, fruits were selected that were characteristic of the varietal phenotype in the phase of biological ripeness: in shape, size, color and pattern of the bark, color of the pulp, size and color of seeds. Results. In the Terskiy early variety, during spring sowing, fruits weighing 3.5-4.0 kg are formed. With summer sowing, the weight of fruits was significantly inferior and did not exceed 2.36 kg. The size of the Yubilyar watermelon fruit corresponded to the declared varietal parameters. The use of foliar application with organic fertilizer AGROCHELATE during the flowering phase did not affect the fruit weight. Analysis of the results of the content of dry soluble substances (DRS) in the pulp of the fruits showed a positive varietal response to the use of feeding. The share of influence on the improvement of the pulp quality indicator was 64.1%. On seed plots, after application of fertilizing with organic fertilizer AGROCHELATE, 0.81-3.09 t more than from control plots, selected fruits corresponding to varietal characteristics. The seed yield is largely influenced by the number of fruits selected for seed isolation. A one-time application of sheet processing made it possible to select a larger number of fruits on the Tersky Early variety - by 289 pieces./ha, on the Yubilyar variety - by 495 pcs./ha. Treatment of plants with organic fertilizer AGROCHELATE in the flowering phase contributed to an increase in the number of seeds in each fruit in the Tersky early watermelon by 19-127 pieces, in the Yubilyar variety by 9-111 pieces, respectively. Unripe seeds in fruits by varieties were 0.9-5.0% less than in untreated plants. In general, watermelon seeds obtained during summer sowing, regardless of the use of agricultural practices, corresponded to the elite category that can be used to grow marketable products.