MSU Extension Vegetables

Weather

A stretch of dry weather allowed a fair amount of field activity to occur last week.

More weather fronts are headed our way, meaning lots of potential for rain. Tropical air is moving in after this morning’s rain, meaning warm, humid air will settle in the area. Tonight and tomorrow, May 23, a cool front moves in, bringing a chance of rain and winds. On Friday, another front moves in, meaning yet another potential period of rain. Next week also looks active, with frequent chances of precipitation. A weak El Nino summer could contribute to a wetter than normal summer season.

The table below shows rainfall totals for the Michigan State University Enviroweather stations in southeast Michigan, as well as degree-days calculated using the Baskerville-Emin Method. Degree-day average for Commerce and Hudson is over five years, while Deerfield is over two years. Soil temperature range in Fahrenheit at 2-inch soil depth over the last week, and rainfall is in inches, with number in parenthesis indicating rainfall since the last report. For a refresher on degree-days and how to get this information in your area, see “Accessing growing degree days with Enviro-weather” from MSU Extension.

General information

The cool wet weather means limited windows for herbicide applications, and less activity from applied herbicides. The constant precipitation likely has led to nutrient loss, so more nitrogen might be needed at sidedress, especially when the plants are dully colored and yellow.

On plastic beds formed with wet soil, you may be able to hold back on starting irrigation for up to three weeks. This will encourage the plants to set deeper roots, meaning higher yields later in the season.

MSU Extension field crops entomologist Christina DiFonzo is reporting black cutworm activity in fields with winter annual weeds in Monroe County. No sprays are necessarily needed, just keep an eye out along field edges and in weedy spots for cutworm activity. More information on what DiFonzo is seeing can be found in her article, “Black cutworms are here.” We have black cutworm of multiple ages present in our area, with some old enough to cut, while others are younger and only capable of feeding along the leaf margins.

Crop reports

Cole crop planting continues. The first wave of flea beetles is active at low levels, and I’ve seen some stunting caused by root feeding wireworms and white grubs. Adult cabbage maggot flight and egglaying is ongoing. Adult imported cabbageworms are flying and laying eggs on warm, sunny days.

Some broccoli curds are beginning to form in early plantings.

Peppers and eggplants are going in on black plastic.

With pumpkin planting on the horizon, I have been fielding questions about timing planting and weed control. Pumpkins typically go in in late May and early June, but soils are still in the 50s in much of our region. Pumpkins germinate best when soil temperatures are consistently above 60 F, so wait until the soil temperatures at a 4-inch depth is at least 60 F. Beyond this, planting date will be determined by your variety and your market.

Depending on when planting is scheduled, it is a good time to do a pre-plant burndown herbicide application for winter annual and summer annual weeds in the field. Try to time it for two weeks out from planting. Shortly after seeding is the next window for weed control—there are a couple of preemergent herbicides available that can be used shortly after seeding. If you are growing jack-o-lantern type pumpkins, Strategy is a good cornerstone of a weed control program. Depending on what other weeds you struggle with, you can mix in some additional products. A summary of some products that can be applied after seeding (adapted from E-433, “Weed Control Guide for Vegetable Crops”) is below.

If growing winter squash or other types of pumpkins, check the product labels or take a look at the weed guide, as there is a lot of nuance in what can be used on what type of squash. For example, pumpkins are on the Dual Magnum label, but winter squash are on an indemnified label.

Rhubarb is being picked. If your rhubarb is starting produce seed stalks, remove them so the plant focuses its energy on the root and stems.

Sweet corn planting continues. If plants look dull, boost the rate of nitrogen at sidedress (it is likely some preplant nitrogen was lost with all this wet weather). Growth and emergence have been slow, so you may need to stretch out timing between future plantings to avoid too much sweet corn being ready at one time.

Processing and staked tomato planting continue as the weather allows.

Meetings

The final Produce Safety Alliance (PSA) Grower Training until fall will be held in South Haven, Michigan, on June 4. This training is required for FSMA compliance (at least one person per farm must take it), and a prerequisite for scheduling an On Farm Readiness Review. Register at Produce Safety Alliance (PSA) Grower Training.

East Michigan fruit educator Bob Tritten is working to organize a meeting on strawberries before harvest starts, so keep your eyes on this space for updates.

Mark your calendar! The 2019 Great Lakes Fruit, Vegetable, and Farm Market EXPO is scheduled for Dec. 10-12 in Grand Rapids, Michigan.