Southeast Michigan vegetable update – Aug. 19, 2020

Dry conditions persist.

Scabs on a pie pumpkin
These scabs on a pie pumpkin have formed post-vertebrate feeding. Some scabs are raised while others hold the shape of the feeding indentations. Photo by Marissa Schuh, MSU Extension.

Weather

The last week brought above-average heat followed by fall-like weather. Parts of our area did receive some rain, and while the U.S. Drought Monitor did remove the abnormally dry classification for most of the area, there are still portions categorized as being in moderate drought.

Looking ahead, temperatures will gradually warm back into 80s as we head into weekend. What happens beyond this is uncertain, as the weather pattern is unsettled. The upside of this is that there will be more potential for rainfall. Next chance of precipitation is Sunday, Aug. 23, into Monday, and then again in the middle of next week. Medium range guidance suggests a cool and unsettled weather pattern for late August and early September.

The table below shows rainfall totals for the Michigan State University Enviroweather stations in southeast Michigan, as well as degree-days calculated using the Baskerville-Emin Method. Degree-day average for Commerce and Hudson is over five years, while Deerfield is over four years. Rainfall is in inches. For a refresher on degree-days and how to get this information in your area, see “Accessing growing degree days with Enviro-weather” from MSU Extension.

Rainfall and degree day totals as of Aug. 19, 2020

Station

Degree days (base 42)

Degree days (base 50)

5-year degree day average (base 50)

Rainfall since April 1

Commerce

2950

1992

1971.3

11.82 (+0.7)

Deerfield

3169

2168

2224.9

10.36 (+0.27)

Hudson

2939

1977

2048

18.07 (+4.64)

Crop reports

Clubroot is being found in cole crops. Make records of areas where you are seeing root galls, and make sure to wash soil off equipment that runs through impacted areas.

Processing and fresh market pepper harvest is ongoing.

Large scale potato harvest is ongoing.

Pumpkins and winter squash continue to take on color. Plants are reaching the end of their lives and foliage is dying back in some fields. Powdery mildew is hastening this process in some spots. Harvest and storage will keep the fruit from getting sunburned and decaying.

Fields bordered by woodlots are seeing some significant deer and rodent feeding. Some feeding will scab over, while other areas are infected by opportunistic pathogens, and both situations can make the original cause harder to diagnose. Context clues are helpful in sorting out scabbed over feeding from something purely pathological. Look at the overall health of the plant as well as overall appearance of the fruit. Are scabs on the fruit on the soil side or upper surface? If on the top of the fruit, how does the foliage overhead look? What is the pattern in the field? Is the damage clustered along the field borders or concentrated along drives and sprayer lanes? Are the other fruit with fresh, deep or generally more obvious (fruit that have been hollowed out, for example) feeding? Asking these kinds of questions can help pick out animal feeding.

In sweet corn, pest pressure has increased but is still manageable. On the corn earworm front, I caught an average of 1.5 moths a night in Monroe County and 1.4 a night in Lenawee County over the last week. We did get some southerly winds with last week’s line of storms, and the small uptick in moths reflects that. A four- to five-day spray interval should get the job done. Western bean cutworm is feeding on foliage, tassels and ears. Corn earworm sprays that are already occurring can provide control before of western bean cutworm before they get to the ear.

COVID-19 corner

The Michigan Agricultural Safety Grant Program from the Michigan Economic Development Corporation is still open to farms with less than 10 employees. Visit their website for full information.

Business management survey

The MSU Extension Business Management Team is looking to expand their programming to vegetable growers. To share your ideas and topics that are most important to you, please complete this brief, three question survey.

Reach out

Please contact me at schuhmar@msu.edu or 517-264-5309 with questions, concerns or to schedule a field visit. I have the ability to visit fields on a limited basis.

Great Lakes Vegetable Producer’s Network

The Great Lakes Vegetable Producer's Network is a live weekly roundtable discussion during the growing-season for commercial vegetable producers in the Great Lakes and Midwest region. It is broadcast live via Zoom at 12:30 ET/11:30 CT every Wednesday from the first week of May to the first week of September. Listen live or later. If you have a pressing vegetable production issue that you would like discussed, simply email it, along with your phone number, to greatlakesvegwg@gmail.com

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