Southeast Michigan fruit regional report – May 6, 2014

More rapid fruit growth is expected later in the week when warmer temperatures finally arrive.


Continued cooler than normal temperatures over the last week has kept the development of our fruit crops at a minimum. It seems as if spring will just not come along this season. Our Michigan State University Enviro-weather stations have only accumulated a few growing degree days (GDD) over the last week. Our season continues to run close to two weeks behind normal.

With rainfall last week and over the weekend, May 3-4, and some green tissue showing on most of our tree fruits, spraying for disease control has been in full swing. On Monday, May 5, and this morning, May 6, light frost was reported at scattered farms across the region with little impact to fruit crops.

Soil moisture was just right at many farms early last week before the rains hit, allowing fruit growers to do a fair amount of planting. Since the rain, most farms have adequate amounts of soil moisture with some having too much. Orchard fertilizer applications are being made as soil conditions allow. Pruning of apples is wrapping up at most farms and brush chopping continues.

East Michigan GDD totals from March 1 to May 5, 2014





Commerce (Oakland)




Emmett (St Clair)




Flint (Genesee)




Lapeer (Lapeer)




Petersburg (Monroe)




Pigeon (Huron)




Romeo (Macomb)




Tree fruits

Apples are mostly at tight cluster and have shown very little movement of bud growth and development over the past two weeks. With the exception of some Honeycrisp and Fuji blocks, most apple blocks generally have a good number of flower buds this season.

Insect pest pressure continues to be very light this week, mainly due to cooler temperatures. Just today I have one report of a few European red mite eggs just starting to hatch. I am continuing to catch a few redbanded leafroller adults in traps and just a few hundred spotted tentiform leafminers in traps. No oriental fruit moths have been caught in traps. I am continuing to see a few predators.

No farms have applied dormant oil, but many are hoping to apply it yet this spring. Remember, if you are considering applying dormant oil, you have to be very mindful of the weather both before and after an application to avoid phytotoxicity issues. Michigan State University Extension recommends you avoid oil applications 48 hours before an expected frost or freeze event and or 48 hours after these same events.

Most of our MSU Enviro-weather stations recorded one apple scab infection period in the last week with most having three to five wetting events. We continue to have apple scab spore release in each rain event with 198 spores trapped in the last one. This is a good number of spores for this early in the growing season, indicating a higher than normal apple scab spore pressure this season. If you had blocks with scab on leaves in 2013, you should not skip covering for rain events with green tissue present. This past week has been a frustrating one for apple growers dealing with so many apple scab wetting events.

Pears are mostly at tight cluster. Pear psylla adults continue to be active in very low numbers with these cooler temperatures, but I started to see light amounts of egglaying over the weekend.

Peaches are in a sad state of affairs at most farms with many varieties not leafing out and flower buds continuing to dry and drop from the tree. The extent of damage from the cold winter temperatures has started to become much more evident in peaches. Trees that were under stress in 2013 or are past their prime appear to be dead or dying. Cambium tissue in twigs, scaffold branches and even trunks that was damaged from cold temperatures this winter is turning from light tan to darker brown. This is another bad sign for the potential of longer-term injury in peaches. It appears that there is extensive winter damage in peaches this season comparable to cold damage that occurred in the winter of 1994.

Sweet cherries are at early tight cluster. I estimate that nearly half of the fruit buds are damaged from cold temperatures this winter.

Tart cherries are at open cluster with no white bud showing just yet. I do not see as much damage in tart cherries as I do in sweet cherries this season.

Plums are mostly at bud break for European types and at late tip green for Japanese types.

Small fruits

Grapes show some slight bud swell in Concord and Niagara. Wine grapes are showing extensive cane death in most varieties. There is between 60-80 percent winter damage in wine grapes at most farms this season.

Strawberry leaves continue to slowly emerge from the crown with poor leaf stem elongation due to cooler than normal temperatures. I have not seen any flower buds emerging from the crown. Frost protection has not begun yet at most farms.

Raspberries are continuing to show signs of winter injury. Some varieties that were starting to show green tips on the buds have stopped new growth and are beginning to shrivel. Canes of summer fruiting types have a significant amount of cambium browning, indicating potential winter injury. Fall raspberries continue to emerge from the ground.

Blueberries are mostly at tight cluster with no bud burst or no green tissue being seen. Some twigs continue to die in many blueberry varieties. 

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