Southeast Michigan fruit update - April 8, 2025

Apples are at green tip and blueberries are at bud swell.

A raspberry bud with green tissue emerging.
Green tissue emerging from raspberry buds at Kapnick Orchards in Britton, MI on April 4, 2025. Photo by Derek Plotkowski.

Welcome to the first in-season fruit article update for southeast Michigan for the 2025 season. Throughout the season these updates will include information about the weather in the past week and the upcoming week, a fruit-by-fruit guide to current conditions with appropriate pest and disease updates, and other relevant observations. 

General observations

We are still early in the season. We are starting to accumulate some growing degree days, but with cool temperatures expected in the next week bud progression will remain slow. The first traps of the season have gone out for a project on ambrosia beetles and the trapline at Trevor Nichols Research Center in Fennville, Michigan, has also started up. Additional monitoring will start towards the end of the month. 

Many of you will have already done spring weed control, but if not, this 2020 Michigan State University Extension article on spring herbicide applications lists some available options. 

This year, our weekly integrated pest management (IPM) updates will be separated into two meetings: a small fruit meeting for southern Michigan held on Tuesday evenings and a statewide tree fruit IPM update on Wednesdays at noon. It is a good opportunity to hear form experts, ask questions and receive restricted use pesticide (RUP) credits. See the latest weekly fruit meetings for southern Michigan on MSU’s Kaltura Media Space (these may take a few days to upload after the meetings are held). 

Fruit-by-fruit conditions

Note: Many of these observations took place last week, but with the cool temperatures there has been little movement in bud development. 

Apples

Green tip in McIntosh was set for March 31 in Romeo. This is used as the biofix for monitoring apple scab. At silver tip, the critical temperatures are 15 degrees Fahrenheit for 10% kill and 2 F for 90% kill. At green tip, the critical temperatures are 18 F for 10% kill and 10 F for 90% kill. At half-inch green, the critical temperatures are 23 F for 10% kill and 15 F for 90% kill. 

Apple_McIntosh_MacombTWP_April3_2025.JPEG
‘McIntosh’ apple at green tip in Macomb, MI on April 3, 2025. Photo by Derek Plotkowski, MSU Extension. 

Blueberries

We are at bud swell in blueberry plantings in Fenton. This is the primary risk period for mummy berry and it is time to start paying attention to phomopsis. FRAC 3 fungicides are reported to be efficacious for both mummy berry and phomopsis. At bud swell we see damage when temperatures drop to the 10-15 F range. 

Blueberry1_Spicers_March31_2025.JPEG
Blueberry buds in ‘Bluecrop’ blueberries in Fenton, MI on March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Brambles

We are seeing some bud swell in raspberries and blackeberries. 

Blackberry3_Kapnick_April4_2025.jpg
Blackberry buds in Britton, MI on April 4, 2025. Photo by Derek Plotkowski, MSU Extension. 

Cherries

We are seeing swollen bud stage in sweet and tart cherries. At swollen bud the critical temperatures for tart cherries are 15 F for 10% kill and 0 F for 90% kill. At swollen bud the critical temperatures for sweet cherries are 17 F for 10% kill and 5 F for 90% kill. 

TartCherry_Spicers_March31_2025.JPEG
Tart cherry bud swell in Fenton, MI on March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Grapes

Some growers are still pruning grapes. I haven't seen first swell in the region, but it has been seen in southwest Michigan. At first swell the critical temperatures are 13 F for 10% kill and -3 F for 90% kill. 

Grape_Spicers_March31_2025.JPEG
Grape trimmings in Fenton, MI on March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Strawberries

We are seeing some greening in field strawberries in Fenton, but no signs of crown formation yet. Early season fungicides should focus on controlling leaf spot. 

Strawberry2_Spicers_March31_2025.JPEG
Leaves greening in field strawberries in Fenton, MI on March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Peaches and nectarines

Peaches in Fenton are at the swollen bud stage. At swollen bud the critical temperatures are 18 F for 10% kill and 1 F for 90% kill. 

Peach2_Spicers_March31_2025.JPEG
Peach buds in Fenton, MI on March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Pears 

Pears observed in Fenton were at bud scale separation. At bud scale separation the critical temperatures are 15 F for 10% kill and 0 F for 90% kill. When blossom buds are exposed the critical temperatures are 20 F for 10% kill and 6 F for 90% kill. 

Pear2_Spicers_March31_2025.JPEG
Pears at bud scale separation in Fenton, MI March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Plums

European plums in Fenton were observed at first swell. At first swell the critical temperatures are 14 F for 10% kill and 0 F for 90% kill. Prune out black knot and dispose of the knots by burning or removing from the orchard. Sanitation is an important step in managing this disease.  

Plum2_Spicers_March31_2025.JPEG
Plum buds in Fenton, MI March 31, 2025. Photo by Derek Plotkowski, MSU Extension. 

Insect conditions

More in-depth information can be found by watching the latest weekly fruit meetings on MSU’s Kaltura Media Space (these may take a few days to upload after the meetings). 

Black stem borer: Females start to search for new sites to deposit eggs around 100 GDD50. The main control is to target emerging females at that point. Our warmest regions are forecast to get to 100 GDD50 next week. 

European red mite: Control for European red mite usually begins at tight cluster in apples and should be completed before the pink stage. 

Green fruit worm: First catches have been reported in Fennville. These can be controlled with insecticides post-bloom. 

Oriental fruit moth: Most of the region is in the egg-deposition control point where you can use of ovicidal products from 100-150 GDD45. 

Pear psylla: Egg hatch will be climbing quickly in about a week 

Rosy apple aphid: Egg hatch is usually complete around the half-inch green stage and control is best applied around tight cluster. 

San Jose scale: A delayed dormant oil spray between green tip and pink can be used to control scale. After this period the next time to control is when crawlers emerge in early summer. 

Spotted tentiform leafminer: Control for spotted tentiform leafminer is usually not necessary, but may be useful in problem areas beginning at tight cluster in apples 

Disease conditions

Apple scab: While a biofix has been set, we are not expecting scab risk for the next week. Early control of scab is important for reducing secondary scab infections that can affect fruit. 

Black knot: There is still time to prune out and burn black knot in plums and sour cherries. Fungicides may be used for limited control to supplement pruning and sanitation efforts. 

Brown rot: This disease affects stone fruit and can proliferate during bloom, but we have not reached bloom yet. Fungicides may be necessary to control if bloom is during a warm period, especially in orchards that have had brown rot presence in previous seasons. 

Cherry leaf spot: We are not expecting cherry leaf spot risk in the next week. See this 2013 article on cherry leaf spot management. 

Grape black rot: Control for grape black rot usually begins at 1” shoot length, but we have yet to see grapes past first swell in the region. See this 2014 article for grape black rot management options and consult E-154. 

Mummy berry: We are in the primary season for mummy berry infections. See the linked document E2846 for control methods. 

Phomopsis: In blueberries the Phomopsis fungus is active from bud swell until after harvest. 

Powdery mildew of apple and pear: You can start to include products labeled for powdery mildew in sprays starting at tight cluster. 

Seasonal weather update

In the last week, southeast Michigan has seen on average of over 20 hours of rain accumulating to nearly 2 inches of precipitation. We are ahead of the five-year average in both time and amount of rainfall. 

Liquid Precipitation Accumulation Mar. 1- Apr. 6, 2025, issued Apr. 7, 2025
Station (County) Rainfall Total (in.) Current Hours with Rainfall Current Rainfall Total Average (5 Yr.) Hours with Rainfall  Average (5 Yr.)
Commerce (Oakland) 4.1 90 3.3 71
Deerfield (Monroe) 4.4 85 3.2 69
East Lansing MSU Hort (Ingham) 4.8 88 3.8 74
Emmett (St. Clair) 4.2 76 3.3 68
Flint (Genesee) 4.8 86 3.8 74
Freeland (Saginaw) 3.8 81 . .
Hudson (Lenawee) 5.4 93 3.8 74
Ithaca (Gratiot) 4.5 85 3.8 78
Lapeer (Lapeer) 4.3 85 3.0 68
Linwood (Bay) 3.4 81 3.5 72
Pigeon (Huron) 3.1 100 2.9 68
Richville/Frankenmuth (Tuscola) 5.6 86 3.6 71
Romeo (Macomb) 4.0 84 3.2 67
Sandusky (Sanilac) 4.2 70 3.1 63
Average of stations in this region: 4.3 85.0 3.4 70.5
Difference in Liquid Precipitation Accumulation from Mar. 1 observed Mar. 31 and Apr. 6, 2025; issued April. 7, 2025
  Rainfall Total (in.)  Rainfall Total (in.)    Hours with Rainfall  Hours with Rainfall   
Station (County) 31-Mar 6-Apr Difference 31-Mar 6-Apr Difference
Commerce (Oakland) 2.5 4.1 1.6 72 90 18.0
Deerfield (Monroe) 2.5 4.4 1.9 66 85 19.0
East Lansing MSU Hort (Ingham) 3.1 4.8 1.7 65 88 23.0
Emmett (St. Clair) 2.2 4.2 2.0 53 76 23.0
Flint (Genesee) 2.5 4.8 2.3 62 86 24.0
Freeland (Saginaw) 2.4 3.8 1.4 61 81 20.0
Hudson (Lenawee) 3.3 5.4 2.0 72 93 21.0
Ithaca (Gratiot) 2.6 4.5 1.9 60 85 25.0
Lapeer (Lapeer) 2.4 4.3 1.9 66 85 19.0
Linwood (Bay) 2.3 3.4 1.2 65 81 16.0
Pigeon (Huron) 2.2 3.1 0.9 70 100 30.0
Richville/Frankenmuth (Tuscola) 2.7 5.6 2.9 63 86 23.0
Romeo (Macomb) 2.0 4.0 2.0 64 84 20.0
Sandusky (Sanilac) 1.9 4.2 2.3 48 70 22.0
Average of stations in this region: 2.5 4.3 1.9 63.4 85.0 21.6

In the short term, we are expecting cloudy and cool conditions through Thursday, April 10, with conditions warming over the weekend. There is potential for rain early next week. Overnight lows  for the next couple days will be in the 20s warming to the 30s over the weekend while highs will climb from the 30s during the week to the 50s and 60s over the weekend.  

In the medium term, we are expecting both temperatures and precipitation totals to be near or slightly above normal. The long lead outlooks are calling for both temperature and precipitation to be near normal. 

Our regional average growing degree day accumulation for the season are ahead of the five-year average by 34 GDD at 42 F, 39 GDD at 45 F, and 19 GDD at 50 F (see table below). This puts us at one to two weeks ahead of normal in most of the region, but at this early stage this may change. Read this Michigan State University Extension article to learn more about degree days: Understanding growing degree-days. 

Degree Day Accumulation Mar. 1-Apr. 6, 2025 Forecast from April 7-12, 2025; issued Apr. 7, 2025
Station (County) Degree Days Base 42°F Current Degree Days Base 42°F  Average (5 Yr.) Degree Days Base 42°F Forecast Degree Days Base 45°F Current Degree Days Base 45°F Average (5 Yr.) Degree Days Base 45°F Forecast Degree Days Base 50°F Current Degree Days Base 50°F Average (5 Yr.) Degree Days Base 50°F Forecast
Commerce (Oakland) 165 122 179 126 87 133 73 47 77
Deerfield (Monroe) 207 165 225 158 122 168 96 69 100
East Lansing MSU Hort (Ingham) 187 137 201 142 99 151 83 55 87
Emmett (St. Clair) 135 104 144 98 73 103 53 37 55
Flint (Genesee) 188 136 200 144 99 152 87 55 91
Freeland (Saginaw) 114 100 126 80 70 88 42 38 45
Hudson (Lenawee) 186 143 201 142 105 151 85 60 89
Ithaca (Gratiot) 146 116 159 106 82 115 58 44 62
Lapeer (Lapeer) 174 129 183 132 93 138 79 51 81
Linwood (Bay) 94 83 106 67 58 75 36 32 39
Pigeon (Huron) 101 86 107 71 61 75 37 33 38
Richville/Frankenmuth (Tuscola) 144 116 155 105 83 113 58 43 61
Romeo (Macomb) 154 116 167 115 82 122 65 43 68
Sandusky (Sanilac) 134 97 141 98 68 102 52 36 53
Average of stations in this region: 152 118 164 113 84 120 65 46 68
Difference in Degree Day Accumulation from Mar. 1, 2025 observed Mar. 31 and Apr. 6, 2025; issued April 7, 2025
Station (County) Degree Days Base 42°F   Degree Days Base 42°F   Degree Days Base 42°F  Degree Days Base 45°F Degree Days Base 45°F Degree Days Base 45°F  Degree Days Base 50°F  Degree Days Base 50°F Degree Days Base 50°F 
  Mar. 31 Apr. 6 Difference Mar. 31 Apr. 6 Difference Mar. 31 Apr. 6 Difference
Commerce (Oakland) 144 165 21.0 112 126 14.0 68 73 5.0
Deerfield (Monroe) 173 207 34.0 136 158 22.0 86 96 10.0
East Lansing MSU Hort (Ingham) 160 187 27.0 124 142 18.0 76 83 7.0
Emmett (St. Clair) 117 135 18.0 87 98 11.0 48 53 5.0
Flint (Genesee) 161 188 27.0 126 144 18.0 80 87 7.0
Freeland (Saginaw) 94 114 20.0 68 80 12.0 39 42 3.0
Hudson (Lenawee) 155 186 31.0 121 142 21.0 75 85 10.0
Ithaca (Gratiot) 122 146 24.0 91 106 15.0 53 58 5.0
Lapeer (Lapeer) 149 174 25.0 117 132 15.0 73 79 6.0
Linwood (Bay) 82 94 12.0 60 67 7.0 34 36 2.0
Pigeon (Huron) 84 101 17.0 61 71 10.0 33 37 4.0
Richville/Frankenmuth (Tuscola) 120 144 24.0 90 105 15.0 53 58 5.0
Romeo (Macomb) 132 154 22.0 100 115 15.0 59 65 6.0
Sandusky (Sanilac) 114 134 20.0 85 98 13.0 47 52 5.0
Average of stations in this region: 129 152 23 98 113 15 59 65 6

HeatAccumulationSEMI_vsnormal_Days_April8_2025.JPG

Watch Jeff Andresen's weekly agricultural weather forecast reports. 

More information and reports on normal weather conditions and departures from normal can be found on the NOAA Climate Prediction Center website, NOAA U.S. Climate Normals website, NOAA Climate Normals Quick Access Page (which may be searched by region), and Midwest Regional Climate Center website. 

 

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