Notes from New York

The most recent editions of Tree Fruit News from New York prepared by Dena Fiacchino has some interesting articles on a variety of topics. I thought I would highlight some of the take home messages from selected articles.

Sprayer Specialist Andrew Landers says….

Sprayers can retain tremendous amounts of pesticide solution when the season is done. Up to 6 US gals of spray can remain in the plumbing system of an average type of air-blast sprayer. Research on boom sprayers puts that figure up to double the amount and more. This retained solution is found in the chemical induction bowl, the booms, the tank, the pump, and its related plumbing. Andrew goes on to discuss sprayer cleaning and rinsing for winter storage. One can appreciate the complications arising from spraying over 40 liters of pesticide "x" on a crop where it is not registered the following spring. Andrew Landers is a Pesticide Application Technology Specialist, working out of the Dept of Entomology NYSAES Cornell University, Geneva, NY.

Grade Standards for Fuji….

Have recently been modified in the U.S. and Canada, and "watercore" or "honeycore" as some call it, is now not considered to be a defect. This trait is considered to be a desirable a feature of this cultivar due to the sweetness it imparts to the fruit. According to Chris Watkins, Postharvest Physiologist working with the Cornell group, mild or moderate watercore should not be a problem in storage of ‘Fuji’ if fruit are cooled prior to reduction of O₂ in CA storage. Severely watercored fruit will breakdown over time and should not be placed in CA storage. Watercore is characterized by an accumulation of the sugar alcohol "Sorbitol" which is 10x sweeter than fructose. Fuji was originally bred and selected in 1930 in Japan for its ability to produce a high incidence of honeycore for markets in Asia.

Rootstocks put to the test in New York….

Researchers and extension workers in New York reported that the winter of 03/04 was the "perfect freeze". Last winter took out 25,000 juvenile trees of different cultivars in the Champlain Valley. Trees were assessed in a 5 acre 3,200 tree test plot holding 16 different rootstocks overseen by Terrence Robinson of Cornell and Kevin Lungerman of Cornell’s Cooperative Extension program in the northeast. They reported good survival rates of selected New York and Canadian rootstocks. The current losses in the Champlain Valley of New York represent 1.23 million dollars U.S. What was outstanding was the hardiness performance of Geneva 16 and Geneva 30 rootstocks along with Ottawa 3, Vineland 1, and Vineland 3. Vineland 1 produces the same vigour as an M26, while Vineland 3 is roughly equivalent to M9 for vigour control.

Prediction of Postharvest Rots Not Easy to Do….

According to Dr. David Rosenberger, spores of postharvest decay fungi are often present on fruit before harvest because P. expansum and Botrytis cinerea are present in orchard soils and in organic debris on the orchard floor. These spores can be blown onto fruit prior to harvest or they can be carried to fruit via soil on bin runners when bins are stacked on trucks or in storage. Spore concentrations on fruit at harvest vary from year to year, but there is currently no way of predicting "bad decay years". As a result Dr. Rosenberger goes on to say that predicting the usefulness of postharvest treatments is very tough to do. It’s difficult to say when they will be beneficial and when they will not be needed.