West central Michigan tree fruit update – July 9, 2024
Print
EmailTart cherry harvest is in full swing. Harvest of early summer peaches may start at the end of the week.
Weather update
Over the past week, high temperatures have ranged from the upper 60s to low 80s. Low temperatures have ranged from the mid-50s to mid-60s, according to the Hart Enviroweather station. Temperatures will be a little warmer toward the end of the week with highs in the mid-80s and lows in the 60s. There has been intermittent rain over the past week, and there is potential for more rain tonight (July 9) and tomorrow as remnants of Hurricane Beryl move through the U.S. Relative humidity ranged from 70 – 87% this week, and evapotranspiration has been high due to high winds. Humidity will remain high through the end of the week and is predicted to peak at 90.2% on July 10 in Hart.
Fruit are growing steadily, and some varieties are developing red color. Based on the Hart Enviroweather station for July 8, current degree-day (DD) accumulation is 1,814 DD42 and 1,075 DD50.
Over the past week, soil moisture ranged from 9–11% at 4 inches deep in the soil profile and 7–8% at 20 inches soil depth for the Hart Enviroweather station. As a reminder, with the consistent and heavy rains this season and continued chances of rain in the forecast, more frequent applications of fertilizer are recommended in smaller rates compared to one or two applications in larger rates during the growing season. This is particularly important for nitrogen fertilizer as nitrogen moves readily in soil solution and can be easily leached as water moves through the soil profile.
Soil temperatures at a depth of 2 inches have ranged from the 70s into the low 80s. High soil temperatures can inhibit root activity and cause stress. Soil temperatures at 4 inches deep have been in the 70s over the past week. Deeper in the soil profile, temperatures fluctuate less and have been in the low 70s and upper 60s at 8 and 20 inches deep. Ground cover and higher soil moisture content from rain or irrigation help keep soils cooler, which could enhance root and soil microbial activity in the soil.
Weather data was gathered from Enviroweather.
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.
Crop update
For early apple varieties, most advanced fruit ranged in size from 58 – 63 millimeters (mm) for Zestar and 55 – 60 for Idared. Honeycrisp fruit ranged from 56 – 60 mm. Gala fruit were 44 – 49 mm and Minneiska fruit were 58 – 62 mm in Hart.
Tart and sweet cherry are continuing to grow and ripen. Fruit size for the sweet cherry variety Regina ranged from 26 – 29 mm. Early sweet cherry varieties have been harvested and later varieties are ready to pick. Tart cherry fruitlets are about 20 – 22 mm in size and red. Tart cherry harvest is continuing across the region.
Cherry leaf spot pressure has been high with warm and wet weather conditions. Lesions on leaves, stems and fruit have been observed across the region. Fruit lesions are not as prominent as fruit ripen and turn red. As the season continues, applications of captan mixed with copper may be the most effective management options for cherry leaf spot. As a reminder, application of copper with high temperatures can lead to phytotoxicity. Do not spray copper products with temperatures above 80 degrees Fahrenheit for several days. Continue protecting leaves from rapid cherry leaf spot infection even after harvest.
Powdery mildew was observed this week in apple and cherry orchards in the region on young leaves at shoot terminals. Powdery mildew is caused by the fungus Podosphaera leucotricha. As a reminder, sterol inhibitors, strobilurins and succinate dehydrogenase inhibitors control powdery mildew. Captan, Scala, Vangard and EBDC fungicides will not control powdery mildew.
American brown rot was observed this week in a mature sweet cherry block and in tart cherries. Cracking from rain or wounding due to high winds, hail, bird damage or bacterial canker infection in sweet cherries leads to higher likelihood of brown rot infection. As fruit get closer to harvest, susceptibility to brown rot increases. Consider if brown rot management is needed.
Peach fruit are growing steadily across varieties, and early peach varieties may be ready for harvest by the end of this week. Venture peach are almost at the pit hardening stage and were 43 – 47 mm in size at the West Central Michigan Research and Extension Center.
Apricots are being harvested. Harvest may be finished by next week. Fruit size ranged from 54 – 58 mm.
Pear fruit were 36 – 40 mm in diameter for Bartlett pear trees at the West Central Michigan Research and Extension Center.
Plums are close to maturity for early varieties. Golden plums may be ready to harvest this weekend or early next week. Early golden plum size ranged from 18 – 22 mm. Average fruitlet diameter for Stanley plum was 27 – 30 mm.
Pest update
Consider scouting reports and block history to target hot spots for orchard pests according to fruitlet stage. Spotted wing drosophila (SWD) was trapped this week in Oceana County at four locations. Japanese beetle was also observed this week emerging from the ground and feeding on leaves of peach and apple.
On July 8, the Trevor Nichols Research Center in Fennville, Michigan, trapped pests such as codling moth, adult obliquebanded leafroller, oriental fruit moth and lesser peachtree borer. These pests were also observed in Oceana County as well as dogwood borer this week. At the Trevor Nichols Research Center, apple maggot was also trapped for the first time this week.
Codling moth counts were one moth per trap on July 8 for three locations across Oceana County. The start of the second generation of codling moth will likely occur soon for some locations. For example, according to the Enviroweather model for Hart, if the first generation biofix date was set at May 20, first adult emergence of the second generation of codling moth was predicted to be July 8. Therefore, the typical treatment timing at the start of egg laying is expected on July 13. Use site specific trap counts to set biofix dates, and consider this article on codling moth management for treatment recommendations and timings.
Dogwood borer was observed this week in Oceana County at an average of 27 dogwood borer per site.
Greater peachtree borer (peachtree borer) has not yet been trapped in the region, but it is expected soon as surrounding regions are trapping these borers.
Lesser apple worm was not observed in traps this week.
Lesser peachtree borer was trapped this week with an average of four borers per trap at the West Central Michigan Research and Extension Center.
Rosy apple aphid and woolly apple aphid are common pests in our region. More woolly apple aphids have been observed over the past few weeks. These pests are becoming more prevalent throughout the county.
Obliquebanded leafroller adults were trapped this week in Oceana County in tart cherry. An average of 3.5 adults per trap were found in tart cherry. No obliquebanded leafroller were trapped in apple this week.
Oriental fruit moth was trapped at two of three locations in Oceana County with an average of six oriental fruit moths per trap. This is the start of the second generation for some locations. Treatment timings for second generation oriental fruit moth will be coming shortly where trap numbers are above the economic threshold (10 or if fruit injury is found). For example, in peaches, if the biofix two date is July 1, typical treatment timing for peak adult emergence is predicted to be July 8 through 12. Peak egg laying is predicted to be on July 15 according to the Enviroweather model for peaches in Hart.
Spotted wing drosophila is still being trapped in Oceana County although trap numbers are lower this week with an average of 24 female and three male adults found per trap. With SWD now present in orchards, check for larvae in fruit to monitor fruit quality. More information and management recommendations can be found in this updated article with trapping information and updated management recommendations.
For pest and disease management recommendations, please refer to the Michigan Fruit Management Guide (E-154) for product guidelines.
For more information about regional reports, please visit the Michigan State University Extension website.
