MSU Extension Vegetables

Weather

The temperatures dipped below 40 degrees Fahrenheit Sunday night, June 2 into Monday morning, June 3. Soil temperatures across much of the region are still swinging between 50 and 60 F. Some areas are seeing 70 F soil temperatures during the day.

After today we should have a nice run of drying days until the next predicted shower next Monday!

You can find more detailed weather information for your area by visiting the Enviroweather station closest to you:

• Emmet
• Fairgrove
• Flint
• Frankenmuth
• Freeland
• Lapeer
• Linwood
• Munger
• Romeo
• Sandusky

Seed and root maggots in cole crops and onions are in their peak egg-laying stages, and European corn borer moths should be emerging this week from overwintered pupae. It could be a good time to target a spray on crops that are in the ground. Here is a table that summarizes the insects of concern and the degree days that signify when they will be laying eggs in the areas around seedlings. I used Lapeer as an example. The Onion Maggot model is from NEWA.

Crop progress in general is truly all over the board. No two farms are alike in this regard. Some farms have crops sitting in transplant trays two weeks or longer beyond their intended plant date. Others appear to be lucky with how the weather has broken on their property and have good drainage. Some are prioritizing their oldest transplants, and others are more concerned with their first cultivation passes and postemergent herbicides. Growers are wondering what kind of prices and supply will be available this year. Will there be a produce glut and price depression as in other years when everyone is on time during peak harvest?

Today, June 5, is the first day that field corn growers can take advantage of Prevented Plant Insurance. Soybean growers can qualify for Prevented Planting starting June 15. Here is a Michigan State University Extension webinar from May 30 with good information on that: Considerations for taking prevented planting option vs delayed planting.

Cucumber beetles and Colorado potato beetles are up and eating potatoes and tomatoes. These beetles overwinter as adults, ready to eat. Spotted cucumber beetles usually migrate up from the south on weather fronts, but I saw my first one yesterday. All of these beetles will feed on other crops until their preferred crop is up. We have seen spotted cucumber beetles and Colorado potato beetles in tomatoes this year already. Imidacloprid drenches and seed treatments at planting are very effective on these pests.

This wet weather has been favorable to slugs and snails on crops. Effective controls include metaldehyde (Deadline, Lock Out), iron phosphate (Sluggo, Ferroxx), and capsaicin (BrowseBan, Miller’s Hot Sauce Animal Repellent).

Melons and watermelons are mostly all at the same stage across the region with 4-6 leaves, but many are still in transplant trays.

Pumpkin seeding was underway in many places. Seedcorn maggot can be a pest of seeded squash and pumpkins.

Transplanted brassicas are parked and not growing much. Some Asian leafy greens have not left the 4-leaf stage after a full month in the ground. Flea beetle pressure has been strong. They sounded like rain hitting the plastic mulch at one organic field I visited last week. While treating for flea beetles, one grower in the region shared that they experienced damage from permethrin on horseradish (Armoracia rusticana), arugula (Eruca sativa) and Chinese cabbage (Brassica rapa). The broccoli (Brassica oleracea) was unaffected.

Permethrin is labeled for all of those crops. This is a curious symptom, and could be a result of the insecticide not drying properly in our cloudy, cool, wet spring, or not drying at the same rate across these different Brassicaceae species with different leaf waxiness. Additionally, EC formulations can sometimes cause burns when mixed with other pesticides or fertilizers.

Radishes, onions, and carrots are also growing slowly. Zack Hayden is currently working on nitrogen rates for onions on muck soils. A common recommendation is 125-140 lbs of N per acre for the full season. Research from 2017 and 2018 in Michigan and New York suggests no yield advantages above between 60-90 lb of full season N. In fact, past studies from 2010-2011 in New York have shown that high N rates increased storage bulb rots, and plants experienced increased thrips pressure and leaf lodging, and delayed maturity. Hayden’s research suggests that muck onion growers can utilize a pre-sidedress nitrate test (PSNT) at the 3-4 leaf stage to see if additional N is necessary. Muck soil density varies widely, which effect the results, but a ballpark threshold at this point is 60 ppm soil nitrate. If your soil already has 60 ppm or more soil nitrate, adding more nitrogen will have little effect on yield, and possibly detrimental effects on quality.

Sweet corn, bean and pickling cucumber planting delays continue for some growers.

Transplanted field tomatoes are purpling from phosphorous deficiency. Depending on the farm, they could have gone in the ground this way from being held in pots and trays for too long without good planting conditions. On other farms, they are purpling because the soils they went into are still not reliably getting over 60 F, and have experienced saturated soil conditions.

Transplanted field peppers look just like they did a couple weeks ago. Last year, southwest Michigan experienced some record spring-time stress conditions both in rain accumulation and heat. The early transplanted peppers never recovered from these stressors, even when the weather turned around and with some added fertilizer to compensate for leaching. We may see something similar this year with peppers that have been in the ground for a few weeks experiencing these cool nights and saturated soil conditions. Sunday night (June 2) into Monday morning dipped below 40 F in some places. Peppers really hate that about as much as freak spring heat waves.

Get togethers

Young Growers Exchange Bus Tour. This upcoming tour is designed to allow the “next generation” of vegetable growers to network with each other while visiting West Michigan farms and is open to all growers in the Midwest. The tour will take place over 2 half days on 17-18 July. Day 1 will focus on soil health, showcasing Morgan’s Compost and a major potato grower who is part of a soil health initiative. Day 2 will include another major potato grower plus muck vegetable production. There has been a lot of grower interest, so early registrations in the grower category are filling up fast. We are also offering a single-day option to allow for additional participants to caravan and leave on their own. Please consider registering:  Connecting the Next Generation of Vegetable Growers.

Michigan Enchilada Sauce Taste Trial. Last year I grew peppers at the research farm for a trial to determine how well we can ripen and dry some large-fruited Mexican peppers here. There are some capacities to sell them as a winter or early spring farmer’s market product or added value sauce-making. Now, a collaborating sauce maker has taken all nine of the poblano varieties that we grew and dried and made enchilada sauces with them to compare against a sauce made from imported Mexican poblanos. Do Michigan poblanos take on a regional flavor that differentiates them like wine grapes? To find out, she is hosting a public tasting trial at the Saginaw Farmer’s Market Demonstration Kitchen on June 15, from 11 a.m. to 1 p.m. Come by!

It is never too early to make accommodations to attend the Great Lakes Fruit, Vegetable and Greenhouse Growers EXPO, December 10-12 in Grand Rapids, Michigan. Hotel blocks are open and tend to go fast. The combination of grower-focused, research-backed presentations and an exhibit hall featuring a diverse set of vendors make it a can’t-miss event.

Please contact me at phill406@msu.edu or 616-901-7513 with questions, concerns, or to schedule a farm visit. You can also send plant materials to MSU Diagnostic Services.