STORAGE ABILITY OF RENETTA SIMIRENKO APPLES TREATED WITH ETHYLENE INHIBITOR AFTER PICKING, DEPENDING ON HARVEST DATE AND TYPE OF ORCHARD
The effect of post-harvest treatment with 1- methylcyclopropene on the change of marketable product output and natural losses during refrigeration storage of Reinette Simirenko apples of mass and delayed harvesting from the orchards on dwarf (M.9) and middle-vigorous (MM.106) rootstocks was investigated. The harvest time is one of the most important factors that determine the storage efficiency and the conformity of the fruit quality to the requirements of customers. To improve the taste and color of apples it is possible to delay in collecting, but the duration of cold storage reduces respectively. Fruits, harvested too late, are susceptible to physiological disorders and over-ripening. Postharvest treatment with 1-methylcyclopropene (1-MCP) of fruits, harvested in different terms, reduces superficial browning of apple skin, low-temperature disorders and fungal diseases and ensures high taste evaluation. Skin and flesh browning of Reinette Simirenko apples, which are susceptible to these functional disorders, appear after 2-4 months of storage and significantly intensify during selling. Therefore the rational duration of refrigeration storage of this variety usually does not exceed three months, while post-harvest handling with 1-MCP increases it by almost twice. The use of moderate-vigorous rootstocks allows the intensification of growing technology. Rootstock effects the growth, yield, fruit quality and resistance to physiological disorders and fungal diseases during storage. Product quality and storage results of fruits from the orchards of various types are improved by post-harvest treatment with ethylene inhibitor 1-MCP. Purpose of the article is the improvement of the storage technology of Reinette Simirenko apples from the orchards on dwarf and middle-vigorous rootstocks by post-harvest treatment with inhibitor of ethylene 1-MCP, the improvement of the fruit taste, the determination of the impact of orchard type and harvest date on the marketable product output, natural losses, the level of functional disorders and microbiological diseases. Reinette Simirenko fruits were selected in Vinnytsia region from an intensive irrigated orchard on dwarf (M.9) rootstock and a traditional orchard on middle-vigorous (MM.106) rootstock. Fruits were collected in two terms - at the beginning of harvest maturity (mass picking) and a week later (full harvest maturity, late harvesting). Fruits were cooled at temperature of 5 ± 1 ° C and relative humidity of 85-90%, and the next day half of the products were treated with 1-MCP on the recommendation of the producer of the Smart Fresh drug. After 24-hour exposure, control and treated fruits were placed in a storage chamber at temperature of 2 ± 1 ° C and relative humidity of 85-90%. It was found out that reasonable storage time of Reinette Simirenko apples at the temperature 2 ± 1 ° C with 90% output of marketable products does not exceed six months regardless of the type of orchard and harvest date. Postharvest treatment with 1-MCP provides high marketable product output (94.9-97.0 %) within seven months of storage with a positive effect on the fruits from an intensive apple orchard on M.9 rootstock. During the storage, a slightly higher level of natural losses was recorded for the fruits from a traditional orchard on MM.106 rootstock. Postharvest treatment with 1-MCP reduces natural losses by 1.3-1.5 times during the seven-month storage. Regardless of the orchard type, non-treated apples from late harvesting were attacked with flesh browning by 1.6-1.7 times more. Postharvest treatment with 1-MCP results in the lack of flesh and skin browning and slows fruit rot development.