Predicted 2010 apple harvest dates
Editor’s note: This article is from the archives of the MSU Crop Advisory Team Alerts. Check the label of any pesticide referenced to ensure your use is included.
This season started out early across the whole state. This year, the state is experiencing a compressed crop development. Green tip was between two and three weeks ahead of normal from far south to far north. Tree development slowed during the cold weather shortly before bloom that moved into the state, but bloom developed ahead of normal for the whole state. What was unique this year is that the whole state was compressed between south and north. Usually, there is a two to three week difference between southwest and northwest Michigan, but this year there was only a seven day difference in bloom dates between southwest and northwest. Bloom dates were one week early in the south and three weeks early in the north.
Apple maturity for 2010 is expected to be seven days early in the south and 21 days early in the north. During and after bloom the daily temperatures can be characterized as cold with numerous frost events occurring throughout the state. The state has a very mixed cropload from block to block, but overall the state has a light crop. The post-bloom cold temperatures will delay maturity and light croploads will advance maturity. Because crops are mixed, heavy to light, there will be a mix of maturity. There also was extended bloom in some parts of the state, which will make harvest dates less accurate.
The early bloom and cold weather following bloom, give us predicted harvest dates (Table 1) about seven to 21 days ahead of normal. These predicted harvest dates are for the center or peak harvest of these varieties for CA storage. This year the 2010 predicted harvest dates are seven to 21 days ahead of normal ahead of last year's predicted harvest dates (Table 2).
Hot temperatures during July and August will hasten the maturity of some varieties. Gala is notorious for ripening early when late summer temperatures are above normal. Other varieties are less prone to hot temperatures advancing fall maturity. Still other varieties ripen when cold temperatures occur near harvest time.
The normal harvest dates for other varieties are listed in Table 3 for the Grand Rapids area. This year's 2010 predicted dates are a rough estimate based on the McIntosh, Jonathan and Red Delicious predicted dates. Other areas of the state should adjust non-predicted varieties based on their own history.