West central Michigan vegetable regional report – May 22, 2013
Vegetable crops are progressing in the west central region with potential disease and insect problems coming.
Asparagus resumed very rapid growth with the warm weather that occurred over the weekend. As a result, many growers resumed picking Saturday (May 18). Because temperatures remained relatively high overnight, some growers had trouble and had to mow asparagus.
Recent wet weather may favor disease development. The chances of purple spot developing will increase in the coming days given our recent rainfall and cooler weather predicted for the remainder of the week. If asparagus is going for processing, purple spot is not a problem unless lesions become sunken and pitted as the blanching process removes the purple color. However, purple spot reduces quality for asparagus picked for the fresh market. Michigan State University’s plant pathologist Mary Hausbeck also noted that Phytophthora spear rot has been detected in Minnesota; recent wet weather could also facilitate development of this disease in fields that have a history of it.
Poor development of carrot seedling side-roots has been observed in one location in Oceana County. Hausbeck mentioned that diseases such as Pythium and Phtyophthora can cause these symptoms. Obtaining samples now and sending them to the MSU Diagnostic Services lab can allow for detection of these diseases. Please contact your Michigan State University Extension county educator if one of your carrot plantings has these symptoms.
Frost covers had been removed from many early celery plantings this week in Hudsonville, Mich., and celery planting is continuing every day.
Planting of summer squash and zucchini will likely begin soon. If your field has a history of Phytophthora capsici, in-furrow treatment with Ridomil can prevent damage to seedlings. The recent wet weather and warm conditions are favorable for early development of this disease. Symptoms in young stands would include damping off and poor stand establishment.
Striped cucumber beetles have also been observed in some parts of the state. At-plant treatments of Admire Pro and Platinum can provide early control of this pest in cucurbits and are labeled for many crops. Far-More FI-400 treated seed contains the same active as Platinum (thiomethoxam); this seed treatment will provide early beetle control, making drenches with Admire or Platinum unnecessary.
As of yesterday (May 21), one of the earliest planted onion fields was in the two- to three-leaf stage in Hudsonville, Mich. Growers had also begun to kill barley windbreaks. Hausbeck mentioned that she has observed onion smut in some onion stands. MSU entomologist Zsofia Szendrei mentioned that she has not observed any seed corn maggot damage this year; temperatures early in the season were likely too cold, while recent temperatures have been too warm, for seed corn maggot problems to develop.
The first radish harvests are now starting in Ottawa County.