Southeast Michigan field crops update – June 3, 2021
The Michigan Wheat Program's 2021 summer field day will be Wednesday, June 9, from 8 to 10 a.m.
Alfalfa and hay
After the first cutting is a good time to apply maintenance fertilizer, including potash and boron. Hay crops remove about 50 pounds of K2O and 12 pounds of P2O5 per ton of dry matter harvested. For established stands, add 2 pounds per acre of actual boron. Stands of hay with at least 40% legume, such as alfalfa, will not need any additional nitrogen. For stands of cool-season grasses, 30-50 pounds of nitrogen per acre will stimulate summer hay growth.
Corn planted into weedy residues are most at risk of black cutworms. Treated corn may have insecticide resistance, depending upon the label. Corn plants will be cut off at the soil level, particularly on cooler and overcast days. Warmer weather, with dry conditions, will soon end damage as the insect pupates. Taller corn also produces its insect chemical defense called DIMBOA.
Soybeans planted in June should be in narrower rows of 7.5 to 15 inches for a quicker canopy by the time the soybeans begin to flower after the summer solstice. The later in the growing season that soybeans are planted, including double-crop, the greater the yield potential due to narrower rows. Higher seeding rates are also recommended as plants will move from the vegetative to reproductive growth stage sooner. The final (harvest) stand should be 130,000 to 150,000 plants per acre.
Overwintering bean leaf beetles will chew holes in soybean leaves, causing concern about spraying. However, plants at this stage can withstand 40-50 percent defoliation of trifoliate leaves without impacting yield. Most farmers tend to overestimate the amount of leaf loss and must remember to examine all leaves and not just one or two at the top of the plant.
Farmers have noticed Canada thistle in fields, which is a consistent threat to crop production and perennial habitats such as cover crops. Fall is typically the best time to manage this weed species, but plants in the bud or early bloom stage can be managed with herbicides. The 2021 Weed Control Guide for Field Crops (Michigan State University Extension bulletin E0434) has a section in the back with suggestions for the management of noxious or problem weeds, including Canada thistle. You can order the guide online through the MSU Store.
MSU Small Grains Field Day
MSU Extension will be holding an in-person small grains field day at the W.K. Kellogg Biological Station, 9702 North 40th Street, Hickory Corners, MI 49060, on Friday, June 25, from 1 to 4 p.m. The field day will showcase research and networking opportunities for those in the small grains industry. This year, 21 winter rye varieties, over 100 spring and winter barley varieties, an oat variety trial, and a small grains fungicide trial will be featured. Participation is free, but registration is requested. The MSU small grains research program has projects for the brewing and distilling industry in Michigan.
MSU Weed Tour
The 2021 MSU Weed Tour is scheduled for Wednesday, June 30, at the MSU Agronomy Farm, 4450 Beaumont Road, Lansing, MI 48910. Pre-registration by June 27 is $30 per person, which includes a tour booklet and lunch. Coffee and check-in are at 8:30 a.m., and the tour of weed control for corn and soybeans will be held from 9:30 to 11:30 a.m.
Adapted from Field Crop IPM Report published by Ned Birkey, Spartan Agricultural Consulting, LLC