West central Michigan tree fruit update – April 2, 2024
Cooler weather has kept buds in a holding pattern in the west central Michigan region.
Weather update
After a mild winter with above normal temperatures, an early March warmup caused some bud changes. Cooler temperatures over the past few weeks have kept buds in a holding pattern, and there has been little change in phenology. Cool temperatures are predicted over the next few days with nights in the low 30s. A warmup next week is expected to lead to some changes in tree phenology and bud development in west central Michigan. As of April 1, 126 growing degree days (GDD) base 42 and 39.8 GDD base 50 have been accumulated since Jan. 1 for the Hart Enviroweather station.
Over the next week, daily high temperatures for the Hart Enviroweather station are predicted to be in the 40s and mid-50s. Lows will be in the low to upper 30s. Some areas in the region may experience low temperatures in the mid- to upper 20s.
About 1.5 inches of rain is forecasted over the next few days in the west central region with possible rain and snow mix. Continue to monitor weather and soil conditions over the next few weeks while completing orchard tasks such as applying dormant sprays, pulling out old orchard blocks, finishing dormant pruning and preparing for planting new trees. When the temperatures do warm up, phenology will likely move quickly.
Weather data was gathered from Michigan State University Enviroweather.
Watch a full weather update from Jeff Andresen, Michigan State University Extension climatologist.
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 varieties, some changes in bud development are occurring, but the movement is slow (Figure 1).
Apple varieties in Oceana County range from dormant to silver tip. Early varieties such as Empire, Zestar and Idared are at silver tip with some green showing. Most buds remain at silver tip in the region for varieties like Gala, Jonagold and Honeycrisp. As a reminder, green tip in apple is 127 GDD base 42 for McIntosh based on over 30 years of observation from Sparta, Michigan. Other apple varieties will be ahead or behind McIntosh. Hart is at 126 GDD base 42.
Tart and sweet cherry buds range from bud swell to almost side green. If growers have not been able to get out in the field yet, there is still time to apply dormant or delayed dormant applications of oil or copper sprays to manage bacterial canker and early pests such as mites or scale.
Peaches are swelling with some calyx green. Venture peach buds are swollen at the West Central Michigan Research and Extension Center in Hart. If growers have not already applied a spray for peach leaf curl, an application for spring dormant sprays using copper products for management of peach leaf curl and bacterial canker is warranted this week.
Some plums and apricots are side white and calyx red.
Pear varieties have bud scales separating and some blossom buds exposed. Dormant applications of oil can still be applied to help suppress psylla and San Jose scale populations.
Pest and disease update
With warmer conditions, pest and disease activity rise shortly in west central area orchards.
Pear psylla adults and eggs were observed at the West Central Michigan Research and Extension Center on April 3. I will be regularly monitoring common orchard pests and primary apple scab infection periods over the coming weeks.
Application of dormant sprays such as oil or copper should occur shortly to manage pear psylla, San Jose scale and hot spots of woolly apple aphids. No pest or disease concerns have been reported for our region at this time. With warmer temperatures coming over the next few weeks, apply dormant or delayed dormant sprays when possible so timing windows are not missed. A reminder to avoid spraying oil if temperatures are around freezing before or after application.
Managing peach leaf curl is important this time of year. Ideal conditions for infection are between 50 and 70 degrees Fahrenheit. Extended cool and wet periods during bud burst can lead to severe infections as fungal spores move through rain and dew. Effective materials include Ziram or copper.
Early season pests to start thinking about include:
- Black stem borer
- Green fruitworm
- Pear psylla
- Redbanded leafroller
- Spotted tentiform leafminor
- Obliquebanded leafroller
- Climbing cutworms
- San Jose scale
- European red mite
For more information about regional reports, please visit the Michigan State University Extension website.