Grand Rapids area tree fruit update
We’re off to a slow start with the cooler temperatures this spring.
Tree fruit growth stages
There is very little movement in tree fruits as of this past weekend. The cooler than normal temperatures have kept all buds pretty tight - even sweet cherry and peach buds. As a reference, in 2010, first green for Macs was on March 23, 2010. Normal first green for Macs in the Grand Rapids area is around April 10-15. The forecast is for slightly warmer temperatures, but still below the average norms.
Growers are wrapping up winter pruning of apples and removing brush from blocks. Ground applied fertilizer applications could be started soon, but with the price of fertilizers, growers should carefully time applications so that they are not wasted by being put on too early. Also, keep in mind the light crop in 2010 and balance your nitrogen accordingly. Tree planting could start in another couple of weeks if the soil warms up and dries out a bit more.
Tree fruit pest management
Copper applications to sweet cherries should be started at the first signs of green tissue showing to help with bacterial canker.
Copper use in apples for the earliest apple scab spray is highly recommended this season. Copper is an excellent scab material. It is thought that apple scab spores mature early with heavy snow cover, so we should be ready for any early scab infections and be ready to cover for them. Preventative scab sprays will be crucial this year mostly because we have control materials that work best ahead of an infection rather than as eradicants.
There are recommendations floating around as to the correct way to prune Macs to prevent the risk of infections from the various canker fungi that have recently infected some strains. When these fungi are sporulating, they can enter through wounds and pruning cuts. Most of the known fungi thought to be involved sporulate at the optimal temperatures between 50 to 60 degrees Fahrenheit. The recommendation to prune at bud break and then apply copper is a poor one as there could be spores that will infect at that time. Try to get Mac strains pruned when it is good and cold and dormant and the fungi are not active.
Also, copper or lime sulfur sprays for peaches should soon be applied if they were not applied last fall. Peach leaf curl is a sporadic disease that we only really see much of every 6 or 8 years of so. Peach leaf curl is favored by cool and wet temperatures early at bud break, but management sprays need to go on well before then.
The Ridge area Code-A-Phone is operational. The number is 616-451-8065.
Spring Spray meeting will be held Thursday, April 14 at Bill and Patrick Goodfellow’s farm on 12 Mile, just west of M-37 near Sparta. Start time is 6:30 PM.