Northeast Michigan field crop regional report – July 15, 2015
There hasn’t been any late blight confirmed in Michigan potatoes this year. Monitor fields when weather conditions are favorable for disease development.
Weather and rainfall
A few soaking rain showers moved through our area at the beginning of this week, good news for sandier fields that were starting to dry out. A total of 0.42 inches fell at the Michigan State University Hawks Enviroweather station between this Monday and Tuesday, July 14. Our next chances for rain will arrive Friday, July 17 and extend through the weekend with a quarter to half inch expected. For the remainder of next week, skies are expected to clear out. The NOAA 6-10 day outlook calls for slightly above normal precipitation across Michigan, while the 8-14 day outlook is calling for normal precipitation amounts in coming weeks.
Growing Degree Days (GDD)
Temperatures cooled off with the rain showers that moved through Monday and Tuesday, with highs only reaching the mid-70s through the middle of the week. However, by this weekend, temperatures will be on the rise again with highs Saturday and Sunday expected to reach the mid to upper-80s. GDD accumulations since March 1 total 2447 base 32, 1570 base 41, and 886 base 50. Northeast Michigan remains on track with 30 year GDD accumulation averages, but Antrim and Charlevoix counties are still lagging a couple of weeks behind. NOAA 6-10 and 8-14 day outlooks are calling for near normal temperatures in coming weeks.
Winter wheat continues to ripen in northeast Michigan and grain development ranges from the milk to dough stages. There are still hardly any signs of Fusarium Head Blight (FHB or scab) throughout Presque Isle, Montmorency and Alpena counties, which is very good news for growers. This is in stark contrast to the heavy scab pressure seen in northwest Michigan and other parts of the state.
Corn development has really taken off in the last week due to warmer temperatures and timely rain. Fields range from the four to ten leaf growth stage (V4 to V10) in our area. Insects to watch for in these growth stages include Japanese beetles, European corn borer, and corn rootworm larvae. Signs of plant disease may be appearing as corn moves into later growth stages. Michigan State University Extension encourages growers to scout for symptoms of Stewart’s leaf blight, Goss’s wilt, Grey leaf spot, and Northern corn leaf blight just before tasseling. If you suspect any disease in corn, please contact MSU Extension.
Soybean development ranges from the latest planted fields in the V2 (two fully emerged trifoliates) stage, to the earliest planted fields entering the R1 stage (first flower). As beans approach the R1 stage, keep in mind that this growth stage is the optimum time for fungicide applications to prevent white mold. While conditions are not as favorable this year for white mold as they were last year in our area, some fields are prone to white mold every year. This is often due to a history of white mold infestation, field locations near water, fields where fog is more persistent throughout the day or heavier soils that stay wet most of the year. Symptoms of white mold will not appear until R3 to R6 (pod set to pod fill), and once disease is present, it is too late for control measures. Therefore, prevention is key to reducing losses to white mold. Some effective fungicides for preventing white mold by order of efficacy are Endura, Aproach, and Proline.
Dry bean growth ranges from the second trifoliate (V2) to the seventh trifoliate (V7) stage. Early planted fields are beginning bloom, and by the end of this week should have at least one open flower per plant (R1 stage). Dry beans are also affected by white mold, so the same preventative measures should be taken in high risk fields. We have not found any western bean cutworm moths in our traps this week, but we will continue to monitor their flight throughout this month in our region.
Potato fields are continuing to flower. Growers should continue to scout for insects, as potato leafhoppers move from alfalfa to potatoes. However, we have not counted many potato leafhoppers in potato fields this past week. There also hasn’t been any late blight confirmed in Michigan this year, but fields should be monitored when weather conditions are favorable for disease development. Late blight favors wet, moderate temperatures, high humidity, and frequent rainfall. The first symptoms of late blight in the field are small, light to dark green, circular to irregularly shaped water-soaked lesions.
Alfalfa harvest continues here in northeast Michigan. Some producers are continuing first cutting, while others are waiting to start second cutting in fields where first harvest was finished early. Some of the largest second cutting regrowth is over 24 in. tall and beginning to bloom. Leafhopper counts in second cutting regrowth are well below levels that would require management.