Southeast Michigan fruit regional report – April 28, 2015

Persistent cool temperatures have slowed fruit crop development and freezing temperatures last Friday morning were close to doing damage to fruit flower buds.

Weather

With cooler temperatures, our tree and small fruit crops have not moved forward in their growth and development in the last week. We have only accumulated a few growing degree days (GDD) in the last week. Our season is running close to a week behind normal in terms of GDD totals. Tree and small fruit growers continue to see green tissue in most of their crops with the exception of grapes.

Our region experienced some unusually cold temperatures last Friday morning, April 24, 2015. A table follows with minimum temperatures for several of our Michigan State University Enviro-weather stations across our region.

Minimum temperatures for southeast Michigan Enviro-weather stations

Location

Minimum temperature

Commerce (Oakland)

24.0 F

Emmett (St Clair)

23.8 F

Flint (Genesee)

24.3 F

Freeland (Saginaw)

26.4 F

Lapeer (Lapeer)

19.7 F

Petersburg (Monroe)

23.3 F

Pigeon (Huron)

27.6 F

Romeo (Macomb)

28.5 F

My initial assessment is that we have had some damage to apples and sweet cherries in a few of the areas that had the coldest temperatures during this event. Some king bloom loss is being found in apples and the most advanced buds in sweet cherries were affected. However, we still have the potential to have a nice crop of fruit in East Michigan. Our fruit buds are pretty tough at this stage of growth and it is too early to accurately make bold predications as to crop damage.

East Michigan GDD totals for March 1 to April 27, 2015

Location

GDD42

GDD45

GDD50

Commerce (Oakland)

185

131

66

Emmett (St Clair)

164

114

56

Flint (Genesee)

228

164

89

Lapeer (Lapeer)

201

147

80

Petersburg (Monroe)

220

159

87

Pigeon (Huron)

122

82

40

Romeo (Macomb)

174

126

67

Tree fruits

Apples are still at half-inch green with a few early varieties at early tight cluster. All areas had an apple scab infection period that started April 19 and lasted until April 21 for most farms, and until April 22 for a few growers. I caught a high number – 90 per rod – of apple scab spores at my trapping location from this event, which surprised me a bit to see such a high number of spores for this early in the season.

Insect activity has started, but very low numbers are being found. A few spotted tentiform leafminer adults are being caught in traps, but their number are still low. Redbanded leafrollers are starting to be caught in traps as well, again with low numbers. 

Pears remain at bud burst with green cluster coming with the first few warm days. Pear psylla adult flight has been slow to develop.

Peaches are at swollen bud to early half-inch green in the south, but it is hard to determine in most blocks because most buds were killed this winter to extreme cold temperatures. I am encouraged to see there is some bloom that survived the winter cold events, mainly to the south and in the Romeo, Michigan area. The surviving buds are mostly on younger trees.  

Sweet cherries are still at bud burst with no early white bud being seen. 

Tart cherries are approaching early white bud. 

Plum damage from winter cold temperatures is extensive in Japanese plums with a few buds being seen that are now at bud swell to green cluster. Younger limbs have more fruit buds on them. There is less winter damage in European plums as they are more cold-hardy than Japanese types. Most European plums are at swollen bud.

Small fruits

Grapes show some bud swelling for Concord types and no movement or growth for European types. There is extensive winter cold damage to wine grapes, however damage varies greatly between varieties and sites.

Strawberry leaves are continuing to emerge from the ground with no flower buds emerging in the crown of the plant. Straw was removed at most farms this week. Michigan State University Extension suggests strawberry growers monitor soil moisture conditions closely as our soils are dry at most farms. If we do not get rainfall by late this week, growers need to irrigate, especially newly planted fields.

Raspberry canes of summer fruiting types are starting to show leaf growth, except for the tips of canes that were killed during cold temperatures this winter. Summer fruiting types also have a significant amount of cambium browning, indicating potential winter injury. Fall raspberry canes continue to emerge from the soil, but are not putting on any extension growth due to cold temperatures. Most canes are only 1 inch in length.

Blueberry growth is the same at bud burst to 0.25 inch green. Initial bud assessments indicated damage in flower buds, but I am encouraged to see as many buds that continue to swell. 

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