Tree sprays and root pruning fail to control rain induced cracking of sweet cherries
W. KoffmannA, N.L. WadeB and H. NicolC
A NSW Agriculture, Agricultural Research Station, Bathurst, New South Wales 2795, Australia.
B NSW Agriculture, Horticultural Research and Advisory Station, Gosford, New South Wales 2250, Australia.
C NSW Agriculture, Agricultural Research and Veterinary Centre, Orange, New South Wales 2800, Australia.
Several sprays and one cultural treatment were evaluated for effects on cracking of sweet cherry fruit (Prunus avium L.) in either the Orange or Young districts of New South Wales.
Screening of chemical treatments was carried out on trees of cvs. Early Lyons, Merton Heart and Ron's Seedling. Mobileaf®, ethyl oleate, calcium nitrate and wetting agents (Citowett® and BS 100®) proved phytotoxic to cherry leaves and fruit and failed to reduce cracking. Gibberellic and naphthalene acetic acids delayed or advanced maturity respectively but failed to reduce cracking.
Experimental work carried out on cherries cv. Supreme and Ron's Seedling included the use of several calcium compounds, (-chloride, -hydroxide), proprietary calcium formulations (Calcium Poly®, Seniphos® plus Stopit®), an antitranspirant (VaporGard®) and root pruning of Ron's Seedling trees on Mazzard and Mahaleb stock. All treatments failed to reduce fruit cracking or to increase soluble solids, fruit weight or calcium content of fruit flesh.
Supreme fruit were smaller and more susceptible to cracking than Ron's Seedling fruit. Ron's Seedling fruit grown on Mazzard stock were firmer and had higher soluble solids than when grown on Mahaleb stock.
Plant Protection Quarterly (1996) 11 (3) 126-130.