West central Michigan tree fruit update – August 9, 2022

The weekend brought heavy rains across the region. Cherry harvest has wrapped up. Peach harvest is underway for early varieties.

Apple, peach, cherry and pear branches.
Figure 1. Stage of tree phenology for apple, peach, cherry and pear in Oceana County on Aug. 8, 2022. Photo by Emily Lavely, MSU Extension.

Weather update

August has started off hot and humid across the region with highs in the upper 70s and 80s across the region. Percent humidity has also been in the 70s and 80s over the past 10 days according to the Enviroweather station in Hart, Michigan. Temperatures will be slightly cooler over the next week with highs in the 70s and lows dipping down into the 50s.

Fruit of apple, peach, and pear continue to grow steadily while sweet and tart cherry harvest is finished up for many growers across the region (Figure 1). Based on the Hart Enviroweather station for Aug. 8, current degree day (DD) accumulation is 2492 DD42 and 1630 DD50.

Storms systems brought rain across the region on Aug. 1, 3, and 7-8. Soils moisture has been low generally this season, but August has proved to be a wet month so far. This latest storm systems brought anywhere from 0.5 – 1.6 inches of rain, and some areas are now above the five-year average for rainfall (Table 2). Scattered showers are possible this weekend, potentially on Saturday evening.

Watch the current and longer-term weather report presented by Jeff Andresen, MSU Department of Geography, Environment, and Spatial Sciences.

Table 1. Rainfall totals from recent rain events on Aug. 1-8, total rainfall from March 1 – Aug. 8, and the five-year average rainfall for Enviroweather stations in west central Michigan.


Rainfall (in)

Total rainfall (in)

5-year Average (in)

Benona / Shelby




Elbridge / Hart
























New Era




Shelby - East




Soil temperatures are warm, and maximum soil temperatures have been in the upper 70s and low 80s. A general consideration is that soil temperatures above 77 degrees Fahrenheit cause stress in roots which may limit water and nutrient update. There is evidence that high soil temperatures, above 86 F, damage roots. Soils with higher percent sand tend to warm up faster than soils with more clay content. Soil moisture also affects soil temperature. Dry soils warm faster than soils with higher moisture content.

Soil and ground management systems that include various types of mulch coverage may moderate soil temperatures and soil moisture levels to keep soils cooler and moister. More information about root stress, ground management systems, and mulch application can be found at the links below.

Weather data was gathered from MSU Enviroweather

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

Crop update

For many growers, cherry harvest is finished for the season. Peach harvest has started for early fresh varieties. Growers are also preparing for harvest of processing peaches and pears toward the end of August. Apple harvest for early varieties such as Zestar and Ginger Gold will likely occur in the next two weeks.

Apple varieties in Oceana County are sizing well. Some varieties such as Zestar, Honeycrisp, and Minneiska are also putting on color. Average fruit diameter for Zestar was measured at 68.9 mm. Average fruit diameter for Honeycrisp was 74.0 mm, and for Jonagold, average fruit diameter was 66.5 mm. Predicted harvest dates for apple are now available from MSU Extension.

Peaches continue to size, and early fresh varieties are being harvested. Average Venture peach diameter was measured at 55.7 mm in Oceana County. For later peach varieties, the pit hardening stage (stage II) should be finishing, and peaches should be in stage III growth. Stage III is a period of rapid growth of the skin and flesh of the fruit. This period is typically four to six weeks before harvest depending on the variety. The recent rains should help size fruit over the next few weeks. Research has shown that, at this stage, additional water through irrigation results in larger fruit size at harvest.

Pear fruit diameter was measured at an average of 51.0 mm for Bartlett pear in Oceana County. A full pear crop is anticipated this year, and pears continue to size well. Other varieties such as Gem and Cold Snap are also sizing well. In some locations, Cold Snap pears had a second bloom in mid-June. This second bloom resulted in fruit set, and pears from the second bloom continue to grow. The pear breeder, David Hunter, who bred the Cold Snap pear (initial selection name ‘Harovin Sundown’) has reported that these fruit mature later than fruit from the first bloom, but they may still be harvestable.

Pest and disease update

Current pests

In the west central region, growers should continue scouting blocks to target hot spots for active pests in the orchard according to growth stage. Hot spots of woolly apple aphids, Japanese beetle, and San Jose scale have been reported across the region.

  • San Jose scale damage has been reported on fruit of apple and pear causing bright red spots. Scout to identify scale hot spots in the orchard. Second generation crawlers are predicted to be present in mid-August.
  • Some European red mites and two-spotted spider mites were observed in low numbers.
  • Pear psylla adults and nymphs were also observed this week at the West Michigan Research and Extension Center.
  • Oriental fruit moth was trapped in Oceana County with an average of eight moths per trap. Codling moth was also trapped this week with an average of only 3.5 moth per trap.
  • Dogwood borer was observed at an average of 46.5 per trap.
  • Lesser peach tree borer, American plum borer, and peach tree borer were trapped in a tart cherry block in Oceana County. Peach tree borer were observed at four borers per trap. Lesser peach tree borer was trapped at 23 borers per trap, and American plum borer was trapped at six borers per trap.
  • Adult obliquebanded leafrollers were also trapped this week with an average of 0.5 adults per trap. Some obliquebanded leafroller feeding was observed on apple.
  • For spotted wing Drosophila (SWD), only two adult females per trap were observed at the West Michigan Research and Extension Center.
  • Apple maggot was trapped this week with an average of 2.5 apple maggot adults per trap at two locations in Oceana County.

Current diseases

With recent rains, growers are encouraged to manage common summer diseases in apples such as sooty blotch and fly speck. Consider managing apples in areas where the MSU Enviroweather model indicates adequate wetting hours for disease. The wetting hour totals vary greatly from station to station this year. For more information, check the summer disease model on Enviroweather for your local weather station.

Development of cherry leaf spot has advanced rapidly in untreated trees at the West Michigan Research and Extension Center. For treatment trees where cherry leaf spot has been managed and the research center, cherry leaf spot lesion development continues to be low. Some growers have put on post-harvest sprays for cherry leaf spot.

For peach, consider managing brown rot and bacterial spot. With recent rains, fruit may be more susceptible to disease development, particularly three weeks before harvest and during harvest.

For pest and disease management recommendations, please refer to the E-154 for product guidelines.

For more information about regional reports, please visit the Michigan State University Extension webpage.

Did you find this article useful?