Southeast Michigan fruit regional report – April 8, 2014

A slow start to spring after one of our coldest winters most fruit growers can remember.

Weather

Winter. We have just experienced one of the most brutal and coldest winters of memory for even our most seasoned fruit growers in the region. We all know we had near record snowfalls and cold temperatures. Many farms and Michigan State University Enviro-weather stations recorded low temperatures this winter in the range of -19 to -22 degrees Fahrenheit. These temperatures occurred in four different events or distinct windows this winter, which is highly unusual, so the coldest temperatures occurred at different times across the region instead of all at one time.

What was also unusual about cold temperatures this winter was the number of times we experienced extreme cold that damages our flower buds. For example, the Lapeer Enviro-weather station had 15 events of -13 F between Jan. 1 and March 5. The temperature of -13 F is where peach flower bud damage occurs. Refer to the Michigan State University Extension article “Winter weather update for 2013-2014” for more details on our winter.

We have experienced cold damage to most of our fruit crops. While it is a bit early in the season to make bold, crop loss predictions, needless to say we will have some fruit crops with a significant crop reduction and some with longer lasting effects to the woody tissue in the trunks and scaffold branches. More details to follow in this report.

Many growers are reporting trunk and scaffold damage from mice and rabbit feeding. Bridge grafting is being anticipated by many growers, others are considering tree removal in young blocks. For more information on bridge grafting, refer to “Bridge grafting girdled fruit tree trunks” by Ron Perry.

Spring. Cold temperatures so far this spring have held back development of our fruit crops much later than normal and have resulted in the latest spring in the 21st century. We have accumulated very few growing degree days (GDD) so far this season as well. I believe we will have one of our latest springs on record.

With warmer daytime temperatures the last few days, fruit crops are just beginning to show signs of bud swell and spring growth. Cold nighttime temperatures have kept crop development to a minimum. Soil moisture conditions are generally wet across the region, with no planting or even ground preparation taking place.

Most growers are far behind normal in their winter pruning, brush chopping and removal, and spring chores in the orchard. Most growers are just starting to tune-up and calibrate sprayers for the season.

East Michigan GDD totals from March 1 to April 7, 2014

 

Location

GDD42

GDD45

GDD50

Commerce (Oakland)

22

13

4

Emmett (St. Clair)

18

10

3

Flint (Genesee)

30

18

7

Lapeer (Lapeer)

26

16

6

Petersburg (Monroe)

30

18

6

Pigeon (Huron)

12

7

2

Romeo (Macomb)

22

13

3

Tree fruits

Apples show slight bud swell to no movement should not be greatly impacted by the cold. Bud burst will be the time when a more accurate assessment can be made as to possible flower bud damage.

Pears show no movement and should not be greatly impacted by the cold. A more accurate assessment can be made at budburst when whole orchards rather than individual buds can be assessed.

Peaches are one of the most cold tender tree fruits and flower bud loss is expected when temperatures fall below -10 F. Most injury occurs between -13 and -16 F. Most growers have significant flower bud losses. However, peach trees can lose many peach flowers and still have a good crop. Many growers are taking a “wait and see” approach to crop loss. It was so cold at many farms that I anticipate damage to twigs, scaffold branched and even trunks.

Sweet and tart cherries remain dormant and show damage to the fruit buds even on good cherry sites. Tart cherries mostly show less damage in the colder sites than sweets; generally two to three dead florets are being seen in the flower cluster bud. These levels of damage are greater than damage from a light frost during bloom or a wet, rainy day during pollination at bloom.

Plum damage is expected in Japanese plums with less expected in European plums as they are more cold hardy.

Small fruits

Strawberry leaves are not emerging from the ground even at our most southern farms, so it is a bit early to remove mulch. Refer to a complete strawberry straw removal article for more information.

Raspberry canes of summer fruiting types have a significant amount of cambium browning, indicating potential winter injury. You can see this browning to the snow line at many farms. Fall raspberries should be mowed anytime now.

Blueberries show no movement. Initial bud assessments indicate damage to flower buds. The damage takes two forms: withered shoots tips that dried from cold winds and subfreezing conditions, and dead flowers in the flower cluster bud. Generally, what we are seeing is several dead florets per bud.

Grapes show no movement. There is little damage in Concords and damage to wine grapes vary greatly between varieties and different fruit sites. 

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