East Michigan fruit update – April 24, 2018

Warmer temperatures over the last few days have finally started to push some early growth in fruit crops.

Weather

With the warmer temperatures over the weekend and early this week, we are starting to see some swelling of buds in most fruit crops. Fruit growers in the Deerfield area and south of the I-94 corridor saw the start of green tissue in apples on a few early varieties early to mid last week. This area has seen more heating this season than fruit growers to the north. All of the eight Enviroweather weather stations that I list in the following table now have degree day base 50 totals in double digits.

Our season is still much behind normal, somewhere between two t0 three weeks. That being said, if we get a string of above average temperatures, late springs can catch up to more normal in a relatively short timeframe. Based on the short- and long- term weather forecast predictions, I expect that we will have a very short or quick bloom period this season.

Most of our region continues to have soils that are too wet to do any fieldwork. Growers are anxious to get started with planting, but I am encouraging growers to hold off a while longer for soils to dry out.

While it is still too early to determine the full extent of flower bud damage from winter cold temperatures in peaches and sweet cherries; the closer we get to bud break, it is becoming more evident that there is damage. This damage is being seen mainly in orchards north of I-94. The coldest days of winter for most of our Enviroweather weather stations was recorded on the mornings of January 6 and 7, and for others the coldest morning was December 28. Low temperatures ranged from -8 degrees Fahrenheit to -15 F for the reporting stations on the list in the following table.  I continue to hear reports from fruit growers that their lowest recorded temperature this winter was -20° F. The weather last fall was relatively mild up to the time either just before or after the New Year when we had a sudden drop in temperatures. I feel that most of the damage to these stone fruit crops occurred at that time. It almost appears that the flower buds were freeze-dried. These damaged flower buds have been slowly dropping throughout the winter.

East Michigan Growing Degree Day Totals for March 1 to April 23, 2018

Location

GDD42

GDD45

GDD50

Commerce (Oakland County)

68

48

23

Deerfield (Monroe County)

94

66

34

Emmett (St Clair County)

55

38

19

Flint (Genesee County)

82

58

31

Freeland (Saginaw County)

57

37

19

Lapeer (Lapeer County)

69

49

26

Pigeon (Huron County)

44

30

15

Romeo (Macomb County)

71

49

25

Tree fruits

Apples are green tip to the south and silver tip to the north. Most growers have a nice crop of flower buds this season. Many growers saw a good amount of San Jose scale damage on fruit last fall as it was being harvested and graded and this winter growers observed high populations of overwintering scale as they did their pruning. Dormant oil applications are being planned in the next week by many growers to help start the process of controlling these scale populations. I have continued to catch a few apple scab spores after the several wetting events thus far this spring at the spore trapping site that I maintain. While several Enviroweather weather stations have recorded an apple scab infection period, there wasn’t any green tissue at the time of infection, so growers did not need to cover for apple scab yet this season. This is unusual! However, most growers now have enough green tissue that the first apple scab spray will need to go on when we have the next infection period. Most growers have finished with pruning apples.

Pears are at bud swell to bud scale separation. I continue to see just a few pear psylla adults, despite cold temperatures.

Peaches are at swollen bud, with some green tissue seen to the south. For growers to the north who are seeing growth in peaches, it is still possible to apply a peach leaf curl spray. I am encouraging growers to hold off the beginning of pruning of peaches until flower buds become more visible to determine any possible crop loss from cold this winter. As was discussed in the weather section of this report, there has been some flower bud damage in peaches this winter.

Sweet cherries are at swollen bud, with no green tissue showing yet. As discussed in the weather section of this report, there has been some flower bud damage in sweet cherries this winter.

Tart cherries are just starting to see some swollen bud, with no green tissue showing yet.

Plums are at swollen bud for European types and Japanese varieties are at side white.

Small fruits

Strawberry mulch has been removed in the last few days at most farms. Leaves continue to slowly emerge from the crown.

Raspberries remain dormant. Most fall raspberries have been mowed off.

Blueberry bud scales have cracked open, with no green tissue showing yet. Pruning continues in blueberries.

Grapes are at dormant. Pruning continues in grapes.

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