Most of Michigan was 4-8 degrees Fahrenheit below normal for the Lower Peninsula with closer to normal temperatures north. Rainfall totals ranged from nothing to 0.75 inches in the western and northern lower regions. Overall, it has been cooler and drier than normal.
Degree day totals are now a few days behind normal in the northern lower and central upper regions, with close to normal totals in the southern lower.
Recent winds high in the sky have been coming from the south, creating conditions conducive to transport of migratory pests from southern climes.
This week’s forecast calls for occasional showers and thunderstorm likely Wednesday in the north, west lower and east upper Michigan, then slowly spreading south and east into central and southeast lower Michigan by this evening and through tomorrow morning. A few strong storms possible in the southeast. Prior to the rainfall, mostly fair, windy and very warm Wednesday in southeast lower Michigan. Showers possible again to the north Friday. Mostly fair and cooler statewide Saturday. Rain possible again statewide late Sunday and Monday.
High temperatures from the upper 60s north to mid-80s south Wednesday, cooling to the 70s Thursday through this weekend. Lows from the upper 40s north to upper 50s south Thursday falling to the upper 40s and low 50s Friday through this weekend.
Medium range outlooks call for a progressive pattern with temperatures gradually warming back to near to above normal levels with normal to above normal precipitation totals through mid-June.
On-farm soil moisture monitoring research opportunity
Michigan State University (MSU) researchers are looking for 10 farms to install soil moisture probes in up to two fields. Cooperators get access to real-time data for both monitoring stations for three growing seasons (fall 2025-fall 2028). Refer to the flyer for more details.
Reach out to Alex Kuhl at kuhlalex@msu.edu if you might be interested or have questions.
Plinazolin
Syngenta is seeking Environmental Protection Agency (EPA) approval for a new insecticide, Plinazolin, which controls pests by contact and ingestion. As an IRAC Group 30 product, it offers a new mode of action for vegetables and supports insecticide resistance management. It’s effective against many vegetable pests. During the EPA registration process, the public can submit comments. These comments help shape final regulations and are most effective when they explain how the rule would impact specific situations. Expressing your opinion through detailed, relevant input is welcome. The comment period ends June 10, 2025. Learn more and submit your comment here.
Field bindweed biology and management
Field bindweed (Convolvulus arvensis) is a perennial weed that is beginning to cause headaches in many vegetable crops. Once established, it can produce persistent root systems to a 15-foot depth or more and can resprout from roots or rhizomes throughout the summer. It can also reproduce by seeds that may last 50 years or more in the soil. Therefore, prevention is a key part to management. Of course that is easier said than done. Once established, management is challenging, but tillage, cover crops and herbicides can help. Effective use of these approaches depends on basic knowledge of bindweed biology, which helps determine the optimal timing and frequency of control practices.
Established stands of field bindweed usually begin sprouting from storage roots in May and deplete their storage reserves for several weeks before developing enough leaves to replenish those reserves. Therefore, killing the plant when it reaches this critical stage (known in plant biology lingo as the compensation point) helps drain root reserves. For field bindweed, this transition point usually occurs when plants have about 4-6 leaves. Tillage to about 4 inches depth at this stage can effectively kill shoots and stimulate dormant buds to sprout, triggering a second flush that further depletes reserves.
Repeating tillage (or applying herbicides) every two to three weeks (whenever plants reach four leaves) will eventually drain the root system, but may not be practical. If fields are removed from cash crop production, two to three cycles of tillage, followed by a thick cover crop (e.g., sorghum sudangrass at 50 pounds per acre) may shade weakened bindweed sprouts sufficiently to deplete reserves without additional tillage. However, roughly 10% of below ground buds typically remain dormant during the summer, so this approach will not completely eliminate the problem.
A more practical approach for many growers involves using systemic herbicides. Systemic herbicides that translocate to roots have the greatest potential to provide long-term suppression. Among these, auxin mimics (e.g., quinclorac, 2,4-D or picloram) are among the most effective (glyphosate less so). Asparagus growers report effective use of quinclorac for bindweed control after harvest. In contrast to tillage, the optimal timing for application of these products is a few weeks after the compensation point is reached (more than the 4-6 leaf stage), when plants will be actively translocating herbicides to their roots as they replenish root carbohydrate reserves.
It is also important to note that the most effective movement of herbicides to roots occurs when plants are healthy and growing actively. When bindweed is stressed (e.g., drought or tillage disturbance) it will not be well controlled by these products.
For more information on field bindweed biology and control, here are a couple good resources:
Crop updates
Asparagus
Purple spot is a yearly problem for Michigan growers and affects all stages of production. At this time of year, rain events trigger a release of the ascospores that overwintered on last year’s fern debris on the soil surface. These ascospores can infect all aboveground plant parts including the spears for harvesting and the fern of young plantings. Blowing soil can cause small, microscopic wounds that provide an easy entry point for the purple spot fungus. Protecting the young asparagus plantings that are not being harvested this year or had a reduced number of pickings are at risk of purple spot infection. This disease will be hard to stop if the pathogen becomes established early in the growing season. Premature browning of the fern severely disadvantages the crown’s reserves and can hurt subsequent spear yield.
Source : msu.edu