East Michigan fruit regional report – May 3, 2016

With cooler than normal temperatures over the last week, growth and development of our fruit crops have been at a standstill.


Temperatures well below normal for most of the last week generally brought growth to a standstill for most fruit crops. The two exceptions are apple and strawberry foliage growth; more details on each in the apple and strawberry sections. As of last Wednesday, April 27, most of our fruit crops were close to a week ahead of normal, but as a result of a cooler week, our season has dropped back to just a few days ahead of normal.

Warmer temperatures are predicted for late this week and over the weekend. If these come to be, then I expect to see rapid growth of our fruit crops. These warmers temperatures will bring a fair amount of bloom to apples, and if there is moisture, the thread of fire blight.

Last Wednesday we had just a few early apples in bloom and daytime temperatures were generally in the lower 60s. That day I saw my first day of good activity of honey bees, bumble bees and native bees. Since then it has been too cold for much bee activity, with the exception of some bumble bees.

Most of our region has experienced many rain events in the past week, bringing an average of 1.2 inches of rain over the five to six days of precipitation being recorded. Our soils are generally wet at this time.

East Michigan GDD totals for March 1 to May 2, 2016





Commerce (Oakland County)




Deerfield (Monroe County)




Emmett (St Clair County)




Flint (Genesee County)




Freeland (Saginaw County)




Lapeer (Lapeer County)




Pigeon (Huron County)




Romeo (Macomb County)




Tree fruits

Apples are mostly at very early king bloom in the southern parts of our region to pink in the rest of the region. Farms closer to Lakes Erie and Huron are much further behind. As mentioned earlier, flower bud development has been at a standstill over most of the last week. However, oddly, leaf growth has continued to take place. Many growers have been asking why their leaves have such a “sickly” appearance to them. I believe that once we get warmer temperatures, the apple leaves will look more normal.

Oriental fruit moth and spotted tentiform leafminer adult trap catches continue to climb, while redbanded leafroller trap catches remain steady. I continue to get inquiries from apple growers this week letting me know they have had a good amount of codling moth trap catches, many enough to biofix. These catches are either some leftover adults from last season that lived over the mild winter, or what I call false coding moth or “lookalikes.”

Apple scab spore discharge has continued climbing with each rain event this past week. Several Michigan State University Enviro-weather stations reported five to six wetting events, with most stations recording one apple scab infection period. Most growers have applied two fungicide covers in the past week to control apple scab. During the overnight rain events Sunday and Monday morning, May 1-2, at my apple scab spore trapping location, I caught 235 spores on the spore rods; this is a good number for my site.

With bloom time coming later this week, apple growers will need to be concerned about fire blight infections. Enviro-weather has a great tool in determining fire blight infection events. MSU Extension also advises growers be on the lookout for oozing fire blight cankers where it was a problem last season.

Pears are at early king bloom. Pear psylla adults continue to fly.

Peaches are at late bloom for some varieties and petal fall for others. Oriental fruit moth trap catches continue. Most growers are finishing up pruning peaches.

Sweet cherries are at full bloom. I am finding some cold damage to flower buds in sweet cherries.

Tart cherries are at first bloom. I am finding about a quarter of the flower buds to be damaged from cold.

Plums are at full bloom for European types and Japanese types are in the shuck. I am finding some cold temperature damage to flower buds in Japanese plums.

Small fruits

Grapes are at early bud burst for Concord and European varieties.

Strawberry leaves continued to emerge over the last week despite cooler to cold weather. Most fields look completely different this week as a result of this rapid leaf growth. Flower trusses continue emerging from the crown. Some strawberry growers have needed to frost-protect in the last week due to cold morning temperatures.

Raspberry leaves continue emerging from the bud for summer fruiting types and new canes continue emerging from the ground in fall raspberries. The longest canes are 3-4 inches long.

Blueberries are mostly at early pink bud. Pruning continues in blueberries.

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