Southwest Michigan vegetable update – June 12, 2019
Planting is mostly caught up, now we need some warm weather.
Degree-day units base 50 degrees Fahrenheit are at 501 for 2019 compared to 681 for 2018 and 694 for the five-year average. We had around 1.5 inches of rain during the week, most falling on June 9and 10. Temperatures ranged from 68 F – 83 F for highs and 47 F – 65 F for lows. Cooler weather has continued to keep plant growth at a slow pace and has hindered the uptake of nitrogen.
Growers have pretty much caught up on field activities. Low tunnels are being removed as plants begin to flower or grow through the openings.
Asparagus harvest in the area is complete. Farm market stands still have it as an offering, but it is either from stored, previously harvested product or from product sourced from further north.
Cucumbers, yellow squash and zucchini grown as transplants and placed under low tunnels are now in bloom and the tunnel material is being removed so bees can access flowers. Transplants not grown under tunnels are not too far behind in flowering although growth is not as great. Direct seeding continues. I have not heard of any reports on cucumber beetles being a major problem.
Early planted potatoes are 14inches tall and close to hilling.
Peas have 2-to-3-inch pods on the earliest plantings. Scout plantings for aphids since they were observed over a week ago.
Sweet corn continues to struggle in the cool temperatures. Growth is not as great as it should be and the color is quite yellow due to the slow uptake of nitrogen. Due to heavier than normal rainfall, consider an increase in nitrogen sidedress applications. Much of the nitrogen applied earlier is probably gone and needs replacing.
With the cool, wet, windy conditions this spring, sweet corn growers may also see an increase in corn smut later this season. Many current varieties have a certain level of tolerance to smut but under heavy pressure, symptoms may still develop. Corn smut needs an opening to enter the plant and this happens with wind-blown, wet sand.
Stakes are being placed in tomato and pepper fields and some early fields are at their first tie. Early non-tunneled tomato plantings are in bloom and some pepper fields are showing first bloom. Some wind damage has been observed in sandy fields where the wind picked up the sand and sandblasted the plants.
Due to the weather delaying planting, many transplants were held in transplant trays longer than normal. This caused stress leading to early flower formation, especially in peppers. In my experience, once peppers flower and set fruit, plant size and future yield is greatly reduced. Do what you can to encourage plant growth before fruit set.
Hops are growing nicely and are 10 to 12 feet up the strings. Complete final nitrogen applications for growth by the end of June when the plants will enter the flowering stage and growth will be minimal.
Rose chafers have been observed and potato stalk borer has been found in tomatoes. Rose chafers have turned into a miner background insect and are not the problem they were several years ago. Potato stalk borer is native but generally not a problem in vegetable crops. View more information on stalk borer from Penn State University. It has several plant hosts including grasses. The reason it was found in tomatoes may be due to the late planting of corn which is also a host.