Southwest Michigan vegetable update – July 10, 2019
Wilting plants are not always a sign that they need to be watered.
The 50 degrees Fahrenheit degree-day units are at 1,067 for 2019 compared to 1,313 for 2018 and 1,269 for the five-year average. We had some areas with no rain for the week while others had 2.5 inches. Temperatures ranged from 82 F to 89 F for highs and 57 F to 71 F for lows. Normal highs for this time of year are near 83 F.
Harvest of early sweet corn is about 10 to 14 days away. Later plantings have much better stands and are greener than those planted early.
Some early potatoes, cabbage and snap beans are being harvested for local farm market and farmers market sales.
Tomato, pepper and eggplant planting is complete. Earlier plantings continue to be staked and tied. Pepper growers need to have 75% of their nitrogen on pepper fields prior to first fruit set. Having increased nitrogen early encourages greater plant growth so that when they do set fruit, the plants have enough leaf area to continue to grow the plant and size fruit. This was especially difficult this year since many plants were held longer than desired prior to planting. This stressed the plants, causing them to flower early and possibly set fruit. Growers with smaller plantings should consider removing that first fruit while larger acreage growers might be able to abort the first fruit by increasing nitrogen levels.
Harvest continues on cucumber, yellow squash and zucchini with no apparent problems. Watermelon, cantaloupe, fall squash and pumpkins continue to runner and flower. If you grow these crops, be aware that downy mildew spores are being caught in southwest Michigan. Therefore, increased control measures are warranted at this time.
Hops are in bloom or close to bloom, depending on the variety. Once hops have bloomed, growers can reduce nitrogen to maintenance levels since plants are no longer in a growth phase.
Garlic harvest will begin soon. For highest quality, plants should be pulled when 50–70% of the leaves have yellowed or browned. Further drying will be needed, but waiting longer will increase yield yet cause the bulb skins to split and not be as attractive. See more information on garlic production in Michigan from Michigan State University Extension.
Recent spotty rains have caused some growers to increase irrigation activities. On sunny, hot days, large-leafed plants such as cucurbits will lose water faster than roots can take it up. Therefore, they often show signs of wilt in the afternoon. This is to be expected and is not a concern; however, if plants show wilt the next morning, there are other concerns that should be investigated. Wilted plants in the morning generally means the roots or vascular system is compromised through disease or insect damage.
The extended planting period for corn and soybeans also extends the period in which herbicides will be applied to these crops, which, in turn, extends the chances of herbicide drift. Vegetable crops are especially sensitive so vegetable growers should be proactive in informing producers on neighboring row crop fields to be cautious when applying their herbicides.