Regional reports on Michigan vegetables – July 6, 2011
MSU Extension educators’ pest and vegetable updates for Michigan.
This week’s regional reports:
- Southwest Michigan – Ron Goldy
- East Michigan (Lapeer, Macomb, St. Clair) – Hannah Stevens
- Grand Rapids Area – Bill Steenwyk
- West Central Michigan – Norm Myers
Temperatures were slightly above normal with highs from 78 to 89oF and lows from 53 to 71oF. The area received no rain to over 1.25 inches. Most of the rain came on July 1 and was concentrated on the western edge of the district.
Direct-seeding of most crops is ending and growers are concentrating on production and harvest.
Pea harvest is essentially done.
Cucumber, summer squash and zucchini harvest volume has increased as direct-seeded fields come into production. Phytophthora symptoms are showing up in some fields and the first squash vine borer was caught this week.
Earliest potatoes are in bloom and have over 1-inch tubers. All stages of Colorado potato beetles can be found.
Tomatoes, peppers and eggplants continue to put on growth and set and size fruit. No harvest has been reported from tunnel-grown plants. Staking and tying continues.
Sweet corn from tunnel-grown plants is at harvest. Early, non-tunneled plants are approaching tassel. One European corn borer was caught this week.
Tunnel-grown cantaloupe harvest will start soon. Non-tunneled cantaloupes and watermelons are runnering off the plastic and are in bloom and sizing fruit. Growth on both of these crops has improved as temperatures and sunshine have increased.
Pumpkins and fall squash are runnering and close to bloom so growers should make final cultivations, sidedress with fertilizer and bring in bees.
No variegated cutworms were caught this week.
Very warm temperatures over the weekend pushed crop growth and development tremendously. Temperatures exceeded 95°F on Saturday (July 2) and brought evening rain to the area of 0.1 to over 1 inch. Transplanting of fall crops continues as well as mechanical weed control and other field activities. Drip irrigation is active as many fields are dry. Some hail damage is apparent, but not severe. Strong, drying winds are causing some stress to larger plants. I have received several reports and inquiries of herbicide injury to crops. Drift or excessive rainfall seems to be the culprit so far.
European corn borer numbers being monitored in one sweet corn field are low in Macomb County and down to less than one per trap in Monroe County. However, a week ago, corn with tassels in the whorl were very vulnerable to injury and ears may already be infested if protective sprays were not applied. Corn needs to be scouted carefully with an eye to the leaves, tassels, stalks and ears. No corn earworms were trapped this week.
On cucurbit crops, growers need to be watching for cucumber beetles as they will be carrying bacterial wilt as well as doing direct injury to small seedlings, even those still in transplant trays, attributable to the late season. Thrips injury may also be noted on these seedlings. Transplants showing feeding injury should not be planted in the field.
Squash vine borers are in flight and will be laying eggs at the base of squash and pumpkins for a month or more. Squash bugs are also active and laying eggs. On the positive side, honeybee activity increased in the past week.
Cucumbers and summer squash are being harvested and melons are setting fruits. The first new specialty potatoes are on the retail market and hoophouse tomatoes will be following soon.
Temperatures have been seasonably warm this past week, but 2011 growing degree day accumulations remain very similar to the very cool, 2009 season. Rainfall during the past week varied from almost nothing to just under 1 inch.
Onions are developing well with variable stand densities. Weed control is the most significant pest problem. Wet conditions earlier this year made timely post-emergent herbicide applications difficult.
Cabbage transplanting continues. Crop growth is good and harvest of early established fields is underway. The last of the winter squash has been planted and zucchini harvest has begun. Tomatoes and peppers are flowering and fruiting with few apparent problems.
Sweet corn is growing well with the recent, warmer temperatures. The more mature fields are in full silk. European corn borer moth counts were only 0-2-0 in my southern Kent County pheromone traps.
The celery crop looks good overall, but growth lags a week or more behind normal. Some have begun to harvest celery hearts. Transplanting is about 80 percent complete. Several fields have a few plants displaying symptoms of celery anthracnose (see photos).
Temperatures have been near normal over the last week. Oceana County had substantial rain on Thursday and Friday of last week (June 30-July 1). Amounts ranged from 0.75 of an inch up to 1.25 inches, depending on the location. That rain has kept the irrigation systems idle for the last week, but if high temperatures and high humidity return as predicted later in the week, irrigation will resume in some crops.
Asparagus harvest is still not entirely complete. One processor continued to receive asparagus through the holiday weekend. The vast majority of the growers finished some time during the previous two weeks. Common asparagus beetles continue to flourish in newly emerging fern. Rust and purple spot are also active. Post-harvest weed sprays appear to have worked well in most places.
Vine crops continue to flourish, but appear to be a week or so behind normal for this time of year. There is some cucumber beetle activity, but very little disease to be found. No reports of P. capsici or any virus.
In carrots, a follow-up aster yellows index done after the previous week’s rains resulted in much higher aster yellows infectivity (6.2 percent) and a new threshold of seven to nine aster leafhoppers per 100 sweeps. I have another sample on the way from the Fremont area and will try to get another sample from Oceana County this week that reflects any migratory leafhoppers that resulted from the last series of rains.
My Tom-Cast net is now active, but we have had to move the numbers from our old web site to the Oceana County MSU Extension portal. Any grower who wants to look at them needs to choose the “Vegetable” section in order to view them.
I didn’t catch any European corn borers in my traps, but caught another two corn earworms. My cooperator now has silks in one field, so I will move my corn earworm trap into the field and trap catches may jump as a result. No western bean cutworms adults yet in my sweet corn trap, but I did get eight in another trap I have in field corn.