Northeast Michigan field crop regional report – July 14, 2016
Several crops are entering the reproductive stages of development, which are critical for yield.
Weather and rainfall
The last week brought continued warm weather and needed precipitation to areas of northeast Michigan. Only 0.27 inches of rain fell at the Michigan State University Hawks Enviro-weather station over the last seven days in two events on Friday, July 8, and Tuesday, July 12. However, isolated storms delivered as much as 1.80 inches in this same period, some of which was accompanied by hail that damaged crops in central Montmorency and Alpena counties.
Precipitation since April 1 is still approximately 4-5 inches below normal, and our region is listed as “abnormally dry” by the U.S. Drought Monitor. Rain will likely return next Sunday, July 17, with chances for thunderstorms through Monday bringing 0.10-0.25 inches of precipitation. The 6-10 and 8-14 day outlooks from NOAA predict near to slightly below normal precipitation in coming weeks.
Growing degree-days (GDD)
Eleven consecutive days of high temperatures above 80 degrees Fahrenheit have pushed along crop development in our region, especially where soil moisture conditions have improved. GDD accumulations since March 1 total 2,604.2 base 32 F, 1,714.7 base 41 and 1,031.6 base 50. This puts northeast Michigan three to 14 calendar days ahead of the 30-year average for GDD accumulation at this point in the season.
Daytime temperatures will dive into the mid-60s tomorrow, July 15, on the tail of a cool front bringing wind and cloudy skies. Highs are expected to be in the upper 70s early next week, climbing steadily to reach the lower 90s by Friday, July 22. The 6-10 and 8-14 day outlooks from NOAA indicate a high probability of above normal temperatures statewide in coming weeks.
Maturation of winter wheat in northeast Michigan has been accelerated by recent warm weather. Stands are quickly lightening in color and grain is in the late dough stage of ripening. Fusarium head blight (scab) pressure has been low, setting the stage for high grain quality. Some have questioned if dry conditions might compromise test weight, but this does not appear to be the case in other areas of the state where harvest has begun. Lady beetles can be found in many stands feeding on stray English grain aphids, but aphid numbers are commonly well below the treatment threshold of 10 per stem. Harvest will likely begin within the next ten days.
Second cutting alfalfa is only 6-14 inches tall, yet stands are beginning to bloom. Producers are encouraged to cut according to maturity, regardless of height, to maintain forage quality and stand condition. However, dry weather during regrowth is expected to reduce second cutting yields by approximately half compared to normal. Leafhopper pressure has increased over the last few weeks, and MSU Extension encourages growers to scout fields for this pest using a sweep net. The treatment threshold for leafhoppers in alfalfa 8 to 12 inches tall is 100 adults or nymphs per 100 sweeps.
Corn in our region ranges in development from the seven-leaf to tassel stage (V7-VT). Once the tassel is fully exposed, silk emergence usually begins in two to three days. Herbicide and sidedress nitrogen applications are largely complete. Some growers are considering foliar fungicide applications to protect corn from diseases like grey leaf spot and northern corn leaf blight. Several factors, including hybrid susceptibility, field disease history, crop rotation, plant date and irrigation frequency should be considered when making the decision to apply fungicides. Susceptible hybrids that were planted late in irrigated fields with a history of fungal disease may benefit from a fungicide application.
Soybeans in the northeast have four to eight fully emerged trifoliate leaves and are beginning to flower. Weed escapes, particularly lambsquarter and ragweed, are becoming a concern. Growers are reminded that beginning flower (R1) is the ideal time for foliar fungicide applications, and full flower (R2) is the cutoff point for glyphosate applications in soybean. However, pre-harvest weed control options are available. Some soybeans are showing signs of potassium and other nutrient deficiencies, which may be related to dry conditions limiting uptake more than low soil concentrations. Tissue analysis at R1 can diagnose these deficiencies and foliar fertilizer applications may be warranted. Nodulation has also been poor in many fields, leading growers to consider applying 50-60 pounds per acre of nitrogen to carry the crop through reproductive growth.
Potato hilling is largely complete. The crop in our region appears to be developing nicely through the flowering period. However, potato late blight has been confirmed in Branch County on volunteer potatoes. According to MSU specialist Noah Rosenzweig, the pathogen favors wet weather with moderate temperatures (60 to 80 F), high humidity and frequent rainfall. While no cases of late blight have been reported in our region, most of the state remains at moderate risk for development of this disease. Northeast Michigan’s MSU and Michigan Potato Industry Commission Potato Field Day is scheduled for Aug. 30.
Dry beans in our region have three to five trifoliate leaves and have benefitted from recent rain. Post-emergent herbicide applications are on-going. A few growers are also applying foliar fertilizers to correct symptoms of zinc and iron deficiency. No western bean cutworm moths have been tapped at our monitoring stations in the northeast. Our Dry Bean Field Day conducted in partnership with ADM Edible Bean is scheduled for Aug. 16.