East Michigan vegetable regional report – August 3, 2016
Everything is being harvested except fall market crops.
August 3, 2016 - Author: Ben Phillips, Michigan State University Extension
A summary outlook overall will mean more irrigation over the next week.
Sweet corn has started to attract vertebrates like raccoons, turkeys and black birds. Western bean cutworm adults have just started showing up. Growers should begin scouting for the white-gray egg masses and tan caterpillars. The University of Wisconsin recommends a treatment threshold of 4 percent of 100 plants, and has a bulletin with nice pictures at “Western bean cutworm: A pest of field and sweet corn.” While field corn is in tassel, the threshold for corn earworm in sweet corn changes to 10 moths per night per trap.
Blossom end rot in tomatoes is starting to even out. Michigan State University Extension suggests greenhouse growers irrigate more to keep this in check.
Sweet peppers are setting fruit again. Over the last week of over 90-degree temperatures, they were aborting flowers. Some growers spray Epsom salts when flowers don’t set fruit, but there is no scientific evidence that works in peppers. Epsom salts are often claimed to be some sort of a cure-all for all sorts of conflicting issues, but in fact there is no evidence for such except that it provides a shot of magnesium if and when plants need it. Of course, some say Epsom salts can bring cooler weather.
Most fresh market potatoes are ready for harvest any time. Some fields have been adversely affected by drought conditions, and are small, stunted and have small leaves. Potato leafhoppers have caused severe hopper burn damage in some fields. Hopper burn symptoms look like a water or nutrient deficiency because the feeding from the leafhopper blocks the vascular tissue of the plant and causes all leaves to curl up and die back from the tips and edges.
Pyrethroids and neonicotinoids work well against potato leafhoppers. Pyganic is one organic pyrethroid option, but there are no effective organic alternatives to systemic neonicotinoids. The Midwest Vegetable Guide potato chapter has a list of treatment options.
Reserve your hotel early for the Great Lakes EXPO in Grand Rapids, Michigan, Dec. 6-8! Registration is not open yet, but hotels often fill up before then. Anyone can access educational session summaries from the Great Lakes EXPO at the website. View the session summaries.