MARKETABILITY AND PHYSICAL PARAMETERS OF REINETTE SIMIRENKO APPLES DEPENDING ON THE COOLING MODE, TREATMENT OF TREES WITH ETHEPHON AND FRUITS WITH ETHYLENE INHIBITOR

Abstract

The article presents the research results of cooling delay, pre-harvest tree spraying with ethylene producer (Ethephon) and postharvest fruit treatment with ethylene inhibitor 1-methylcyclopropene (1-MCP) on changes in marketability and physical parameters of Reinette Simirenko apples during long-term cold storage. The research was carried out at Uman National University of Horticulture. Two weeks before the expected harvest, trees were sprayed with a physiologically active substance Еthephon (еthrel, 180 g/ha) with the addition of NAA (potassium salt of α-naphthylacetic acid, 20 g/ha); control plots were sprayed with water. The apples were collected in the stage of early harvest maturity. On the day of harvest, one part of the fruits was cooled at a temperature of 5 ± 1 ℃ and a relative humidity of 90–95% and the next day treated with 1-MCP (SmartFresh, 0,068 g/m3). The other part of the apples was exposed for three days at a temperature of 16 ± 1 ℃ with subsequent cooling to 5 ± 1 ℃ and treatment with 1-MCP. The fruits were stored for six months in a KHR-12M refrigerating chamber at a temperature of 2 ± 1 ℃ and a relative humidity of 90–95%. Regardless of the cooling regime, it has been established that the rational storage duration of apples collected from trees without Ethephon treatment is up to six months (with 90% standard fruit output), while when sprayed with Ethephon, only immediately cooled fruits are stored for the same period. Treatment with the ethylene inhibitor 1-MCP provides a high standard fruit output 97%, regardless of Ethephon tree spraying and the fruit cooling delay. At the end of storage, when trees are treated with Ethephon and a three-day post-harvest cooling delay occurs, the skin’s light reflection increases rapidly and the flesh firmness decreases. Regardless of Ethephon treatment and cooling, the change in ground skin color and firmness is slower with post-harvest apple treatment with 1-MCP. During storage, the dependence of apple firmness on the level of light reflection by the skin at 675 nm is inversely linear, and the dependence of standard fruit output on density is linear. The standard fruit output, light reflectance, and the firmness are determined primarily by the postharvest apple treatment with 1-MCP. Pre-harvest tree treatment with Ethephon and the cooling regime of fruits have a weak effect on the firmness and standard fruit output (2–4%), and the influence of these factors on the skin light reflection was found to be within 12–14%.