Northeast Michigan field crop regional report – July 30, 2015
Dry weather is setting up a timely wheat harvest, but other crops face moisture stress.
Weather and rainfall
It has been over two weeks since any significant rain in northeast Michigan, leaving our fields excessively dry. Over the last month, rainfall totals have been 1-2 inches below 30-year averages. Irrigation systems continue to run as growers attempt to keep adequate moisture on fields. Looking ahead, the next chances for rain in our area will arrive this weekend into early next week, but showers are expected to be widely scattered. NOAA 6-10 and 8-14-Day Outlooks are calling for near normal precipitation totals in coming weeks. If our region does not receive significant rainfall in the next week or so, a D0-D4 level drought situation will likely be initiated.
Growing degree days (GDD)
High temperatures the last seven days have ranged from the low 80s to mid-90s. Overnight lows have been warmer as well, ranging from the low 50s to low 60s. GDD accumulations since March 1 total 2,960 base 32 degrees Fahrenheit, 1,957 base 41 and 1,150 base 50. Most of northern Michigan continues to follow normal trends for GDD accumulations this year, except for a few northwestern counties that are still lagging behind by an average of one calendar week. The current heat wave is expected to break over the next several days, with high temperatures retuning to the mid-70s. NOAA 6-10 and 8-14-Day Outlooks are calling for below normal temperatures in coming weeks.
Winter wheat has reached physiological maturity in most northeast Michigan fields and harvest has begun. Head scab has not been an issue across our region, and with the very dry weather we have been experiencing, sprout should not be much of a problem this year either. Growers of high quality white wheat can expect to receive a premium price at market due to the moderate to high DON levels detected in other parts of the state.
Corn growth has continued in the hot weather, but lack of rain is a concern as fields planted the earliest are entering pollination (R1). Pollination is a critical time for grain yield determination because drought stress can throw off timing between the development of pollen and silk elongation, or desiccate silks already present, resulting in poor fertilization. Later planted fields still have a week or two of vegetative growth yet before they tassel, as they are in the eight to 10 leaf stage (V8-V10).
Soybean development is still widely variable across the region. Growth ranges from the five trifoliate stage (V5) to podding (R3). While the dry weather we have been experiencing has decreased chances for white mold, it is also decreasing yield potential, as soybeans will abort flowers and pods in times of drought stress.
Dry bean growth has really taken off in the last week, as most acres are in the mid-flower to mid-pod set stages (R2 to R4). We have seen a slight increase in western bean cutworm flight this past week, but we are still well below the economic threshold for insecticide applications. The greatest number of moths has been collected at our northernmost traps in Moltke Township where additional GDD accumulation and coarser soils seem to favor higher western bean cutworm numbers and an earlier flight. Presque Isle County Michigan State University Extension will continue monitoring moth numbers through August.
Second cutting alfalfa is in mid-bloom and harvest has resumed for some producers in our area. Others that focus on grass hay are still continuing to finish up their first cuttings. Presque Isle County MSU Extension is participating in a statewide research project looking into possible sulfur deficiency in alfalfa. We submitted samples from several fields in the region and expect that at least some will come back deficient. Atmospheric deposition of sulfur has been greatly reduced in recent decades as we improve air quality and sandy soils with limited organic matter content are often the first to develop deficiency.
Potato tubers are set and have begun bulking in our region. Most tubers are 1-2.5 inches in diameter. Late blight was confirmed in Michigan last week in Montcalm County. MSU has identified the strain of late blight as US23, which is Ridomil sensitive. While late blight has not been observed in our area, growers are encouraged to scout fields weekly and maintain a tight fungicide application schedule.