OLIVE HARVESTVANT, A NEW HARVEST-AID FORMULATION FOR IMPROVING FRUIT ABSCISSION AND MECHANICAL HARVESTING

High costs and low labor availability at olive harvest time are the main economic constraints in oil and table olive production, reaching 40-60% of the total income. This subject has been a top priority for several decades, leading to the adoption of mechanical harvesting solutions using various types of tree shakers/vibrators. These alone are not efficient enough, and at optimal conditions (variety, tree shape, temperature, ripening, etc) produce up to 85% fruit release, and the necessity to follow up with a completing manual picking. Chemical harvest- aids have been investigated for more 35 years, as pre- harvest treatments for loosening fruit, in order to improve the mechanical harvesting efficiency. Use of Ethephon is currently adopted in a limited number of countries. It has some negative effects at the recommended rate, substantial leaf shedding (aggressiveness), and high cost per treatment. For the last 5 years Agrovant Co. has conducted experiments with HarvestVant. This is a double action product, controlling the abscission process by inducing endogenic production of ethylene at the pedicel zone of the fruit by a special P salt, completed by some exogenic ethylene supplied by a substantially reduced rate of Ethephon. The well balanced and stable formula is controlling the effects via the built-in proprietary long lasting penetratant "FertiVant" adjuvant. The current work was done on Picual, Arbequina, Hojiblanca, Souri var., are part of the intensive efforts during the last few years of research, mainly in Israel and Spain, to reach optimization of the formulation under suitable working conditions. The product is now at its final regulatory stage in these countries, to be used commercially on oil olives. Best results are obtained by spraying 3% HarvestVant when trees approach the ripening stage, as identified by a proper FRF (Fruit Retention/Release Force) measurement. Spraying at a FRF of 500-700 g/fruit, will reduce FRF to 200-300 g/fruit within 7 days. Providing good fruit loosening for mechanical vibrating. This is subjected a proper canopy coverage with the spray solution, using a suitable volume to reach "every fruit". Over 95% of the fruits are harvested by one pass of the shaker, at a shorter time, without the need for complementary manual hand picking. This is also achieved with a limited leaf shedding, no residues of ethephon in the oil, and excellent cost/benefit ratio for the grower.