Field crop weekly IPM report for Southeast Michigan
EAST LANSING, MI. – Weather - Despite four days of 70ºF air temperatures over the past nine days, soil temperatures suitable for planting corn or soybeans remains below the benchmark germination threshold of 50ºF. The soil temperature taken at the MSU Enviroweather station located at Applewood Orchards in Deerfield reached a high of 49 degrees once in March, but has since been hovering in the low to mid 40’s. A year ago, soil temperatures were still in the mid 30’s. The recently updated 30-year average spring freeze date (28ºF) is April 13 and the updated spring frost date (32ºF) is April 25.
Spring Seeded Hay - Spring is not the ideal time to seed new stands of hay due to weed competition. Even starting with a clean field, legumes such as alfalfa take more time to emerge so a companion crop such as oats is usually recommended. A first cutting of new hay should wait till the early bloom stage, about 60 days for a legume or 70 days for grass hay. Even though many weeds can be nutritious, they will compete for light, moisture and nutrients in an expensive alfalfa seeding. Established fields should be scouted now for the control of winter annual or biennial weeds. Herbicides applied now to small or rosette stage weeds offer the best chance for control.
Corn - The March 31 USDA Prospective Planting report forecast increased through lower corn acres in Michigan and the US than traders were expecting. Despite high fertilizer prices, there is tremendous market pressure to plant more acres to corn. With a favorable April forecast and a NOAA summer forecast of warmer and drier weather, many farmers will likely start running the planters after Easter. One key will be clean fields to give the crop a good start. MSU, OSU and other land-grant university agronomists consistently recommend controlling weeds while small, two to four inches, depending upon the species. Taller weeds will compete with the crop and can easily get out of control if there is a rainy spell in April.
Soybeans - The same March 31 USDA report also forecast increased acres to soybeans this year, though the acreage was lower than trader estimates. There is a real danger of the soybean “pipeline” running dry late this summer if exports and use remain high prior to fall harvest. Many farmers still overplant soybeans and can easily save $5 per acre by simply cutting back on the seeding rate from 160,000 to 130,000 seeds per acre. Consistent research has shown that more seeds will not translate to higher yields as more soybean plants generally have fewer pods while fewer plants have more pods.
Winter wheat - Overwintering wheat in Monroe and southeast Michigan generally looks in very good condition and is rapidly approaching the Feekes growth stage 4. There should not be any freeze damage due to the low air temperatures of March 31 and April 1 as the growing point in still in the soil. There may be more profit potential to farmers in their wheat than if they tear up good stands to plant either corn or soybeans. All farmers should apply no more than half of their spring nitrogen now and wait until the plants elongate at Feekes stage 6 to apply the rest. Farmers not interested in wheat straw may wish to consider adding additional nitrogen with a plant growth regulator at Feekes stage 5 or 7.
Sprayer Calibration - All farmers who apply their own pesticides are required to calibrate their sprayers at least once a year and then document it in their spray record book. There are only three variables to consider in calibration; ground speed, nozzle spacing and nozzle flow rate. Since most farmers do not change their nozzle spacing, that simplifies the process to an hour or less. The new dicamba labels have much stricter label requirements (and limitations) of wind and ground speed, nozzle selection and spray pressure, buffer zones, additives and adjuvants, tank mixing order, tank cleanout procedures, Endangered species and recordkeeping. The advantage of using the dicamba resistant crops is when glyphosate resistant weeds are present, so farmers must weigh the tradeoffs carefully.