The effects of CaCl2 and aqueous seaweed extract foliar sprays on spider mite predator/prey status and on several aspects of fruit quality of 'McIntosh' apple trees.

Sprays of CaCl^ and an aqeuous seaweed extract (Cytex) were applied in 1977 and 1978 on 'McIntosh' apple trees (Malus domestica Borkh) on MM106 rootstock that received no insecticides or miticides with the exception of a dormant oil spray in 1977. Mite populations were not affected by the spray treatments in 1977. Cytex sprays at 2x concentration reduced 2-spotted mite and apple rust mite numbers in 1978 and the European red mite population was lowered by appli¬ cations of CaCl2Limb circumference increase was suppressed both years by CaCl2 sprays because of foliar burn and high mite numbers. In 1978, CaCl2 sprays reduced foliar chlorophyll, fruit size, and fruit flesh firmness after storage at 32° F in air but increased red color, internal ethylene concentrations, preharvest drop, and brown core of fruits. Cytex sprays increased fruit set in 1978 and fruit flesh firmness both years.