Be sure to protect your fruit from rots: bitter rot on Red Delicious. (Photo credit: K. Peter)
Not only a headache in the field, but the fungi causing fruit rots can be quite stealth since spores will land on the fruit and cause symptoms only after the fruit have been in storage. This is especially significant if your apples are headed for a packinghouse or even fresh market.
We are in the midst of evaluating Serenade Optimum and Oso 5% SC for summer disease control; we hope to evaluate Double Nickel next year. Last year when Serenade Optimum (16 oz/A) was used as the last two cover sprays, we observed good results for controlling rots in the field and during storage. We are repeating the trial again this year. Pome fruits were added to the Oso 5% SC label last year, specifically for control of summer diseases. We are in the process of putting the product (6.5 oz/A plus LI-700 1 pt/100 gal) through its paces under PA conditions this year.
As you're getting your orchards ready for harvest, some general management techniques to keep in mind to reduce postharvest fruit rots:
When controlling for disease, weather and tree growth conditions need to be monitored at a local level within one's own orchard. Before chemical products are applied, be sure to be in compliance by obtaining the current usage regulations and examining the product label. Product information can be easily obtained from CDMS.