Effect of growth regulators on productivity and quality of tomato crop under Volga delta conditions

Relevance. Tomato considered a significant vegetable crop that plays a prominent role in the field of human health. At present, there are large numbers of tomato cultivars with a wide range of morphological and sensorial characteristics which determine their use. Farmers often use some chemical substances which have similar structure and activity with endogenous plant hormone called (exogenous) as a low-cost alternative to regulate plant growth and increase yield. Thus, the use of Plant Growth Regulators (PGRs) has become an important component of the agro-technical procedures for most cultivated species.Methods. This study aims to evaluate the effect of four growth regulators (Krezacin, Chitosan, Zircon and Energene) on growth, productivity and quality of two Russian tomato varieties (Moriana and Superjol) under delta Volga conditions. Each type applied three times on both cultivars (Soaking tomato seeds before sowing, spraying on plants at vegetative phase, spraying on plants at flowering phase with three replications.Results. The results showed that; combination between Energene and cultivar Moriana enhanced the most of studied characters (Germination – 83.1%, fresh weight of Arial parts – 241.9 g, dry weight – 74.4 g, Number of № flowers/plant – 51.0, № fruits /plant – 35.6, fruit set – 69.8%, plant yield – 2.44 kg, TSS – 5.1°Brix, Content of Ascorbic Acid – 25.6 mg/100 g); Interaction between “Energene x Superjol” gave the maximum value for Plant height (85.6 cm), Fruit weight (72.6 g); while “Krezacin x Moriana” registered the highest fruit dry matter (6.77%) and Acidity (0.53%); Applying Zircon on Cultivar Moriana increased number of leaves/plant (56.8) and nitrate contents (27.6 mg/kg); the maximum LAI (150.1 cm2 ) obtained from interaction between Chitosan and cultivar Superjol whereas, “Chitosan x Moriana” treatment gave the highest level of Carotenoids (4.12%).