Palevsky, E., Oppenheim, D., Reuveny, H., Gerson, U., 1996.
Impact of European red mite on Golden Delicious, Oregon Spur apples in Israel. Experimental and Applied Acarology, 20: 343-354.
Abstract
To develop a damage threshold for Panonychus ulmi, the effect of injury on fruit weight, return crop in the apple cultivars Golden Delicious and Oregon Spur were studied in Upper Galilee, Israel, during 1992-93. Damage significantly affected the leaf colour, chlorophyll content, fruit weight and return harvest for both cultivars. High population levels of 450 adult female cumulative mite days (ACMDs) reduced the fruit weight on Golden Delicious but not on Oregon Spur. Population levels above approximately 600 and 900 ACMDs in Golden Delicious and Oregon Spur, resp., caused a substantial reduction in the return harvest. Because no damage was observed at low population levels, an action threshold of 150 ACMDs is recommended.
