West Central Michigan vegetable regional report for May 28, 2014
Warmer, drier weather has crops and pests moving in West Central Michigan.
As of last Thursday, May 22, asparagus growers were still on early pickings in areas not damaged by frost. Consultants reported seeing very few common asparagus beetles as of last Thursday, but this could change with warmer weather. Crown planting dates have been variable this year with some crowns planted in early May and others areas still being planted as of last week. Planting crowns before the end of May is important to allow enough time for fern to develop and begin to save up energy to use in building new roots and shoots for next year.
As of last Thursday, May 22, consultants reported that carrot planting had finished in Oceana and Mason counties. Aster leafhoppers were present at very low levels in one Crystal Township, Michigan, wheat field I swept last Thursday.
Aster leafhoppers were collected in celery fields in low numbers from an Ottawa County and Kent County location this week.
In cucurbits, winter squash planting was commencing in Mason and Oceana counties as of late last week, and was ongoing at one farm in Ottawa County. One question growers have asked, “Do I need to apply Capture (active ingredient bifenthrin) at planting if I also am using Far-More-treated seed?” A single-year trial in New York state treatment of cucumber seeds with the active ingredient found in Far-More FI-400 (thiomethoxam) was as effective on its own in protecting against seed corn maggot as an at-plant treatment with Capture.
In addition, past research has shown that after maximum soil temperatures at a 4-inch depth regularly reached 70 degrees Fahrenheit or higher for five-day stretches, the risk of seed corn maggot damage is greatly reduced. Currently, soil temperatures at 4 inches have been slightly below 70 F, but have been increasing. If they warm further over the next week, it will reduce the risk of seed corn maggot damage. Factors that will maintain a higher risk level include a recently killed (less than three weeks) cover crop, recent manure application, or soil with higher organic matter as seed corn maggot pressure is higher in cool soils with high organic matter.
Maximum soil temperatures at 4-inch depth for the Hart, Hudsonville, Ludington and Sparta MSU Enviro-weather stations have been on the rise
Onions were in roughly the two to three leaf stage in Hudsonville, Michigan, yesterday, May 27, with some replanted fields in earlier stages. Barley windbreaks were dead or dying. Thrips were present at very low levels in one area field in Ottawa County yesterday. As the thrips season approaches, remember that while Movento (active ingredient spirotetramat) has proven to be an excellent first spray in rotations for onion thrips, do not apply it before thrips are present; a threshold of one thrip per leaf can be used to decide if an application of Movento is necessary. If you apply it before thrips are present, you will be wasting part of the life of this product – it can provide two to three weeks control – which could mean you will have to spray more later if its activity wears out and thrips populations increase.
Research has shown that scouting your fields will help you hit the sweet spot, saving you money in the long run and allowing you to apply product before thrips populations skyrocket while not wasting it when they are not abundant. Michigan State University Extension has additional information on how to scout for onion thrips and onion thrips spray rotations.
Potatoes were roughly 4 inches tall this week in Southwest Michigan, and just emerging to our east in Montcalm County.
There was an uptick in captures of black cutworm adults in sweet corn to our east in Isabella County, while one moth was captured in an Ottawa County trap (over five days). This suggests that flights have occurred, but are spotty, with some areas experiencing higher populations of female moths that could lay eggs. After a significant trap catch, it takes roughly 300 growing degree days base 50 F for larvae to be large enough to cut plants.