PERFORMANCE OF DAMINOZIDE AND ETHEPHON WHEN APPLIED IN LOW-VOLUME SPRAYS TO SOUR AND SWEET CHERRY

The performance of daminozide and ethephon was evaluated on sour (Prunus cerasus L.) and sweet (Prunus avium L.) cherry, respectively, using promotion of fruit abscission as an index of response. No significant change in daminozide performance on sour cherry was observed when a fixed dose was applied at various carrier volume rates (94 to 2350 liter/ha). In contrast, there was a marked increase in response to a given dose of ethephon as carrier volume was reduced. Acceptable abscission responses were obtained from lower doses when ethephon was applied in low volume (40 or 80 liter/ha). The distribution of spray deposit over the tree was less uniform as spray volume per hectare was decreased.