Southwest Michigan vegetable regional report – July 16, 2014
The wet, cool weather continues to be an issue in southwest Michigan, increasing the possibility of disease and hampering field activities.
According to the Michigan State University Benton Harbor Enviro-weather station, the area received 0.65 inches of rain for the week. Temperatures were below normal with highs from 65 to 82 degrees Fahrenheit and lows from 53 to 66 F. We are at 1,271 base 50 growing degree days (GDD), putting us 72 units behind 2013 and 117 behind the five-year average.
Field activities continue to be slowed due to rain. Since June 1, we have had 26 days where it rained. Many fields have standing water hampering harvesting and other activities.
Vine crops. Wind has caused damage to large-leafed cucurbits that have just come into flowering and don’t have the weight of developing fruit to hold them down. There are also reports of poor pollination due to poor weather. This will lead to fruit abortion and poorly shaped fruit. Growers should expect earlier development of powdery mildew and downy mildew. Both diseases do best under cloudy, wet, windy conditions. Control products should be applied earlier than in a normal year.
Windy weather with heavy driving rains will contribute the spread of many diseases in tomatoes and peppers, especially the bacterial diseases. Michigan State University Extension advises growers to maintain a tighter than normal spray schedule and to always include a copper product. There have been no reports of tomato harvest at this time, but harvest from tunnel-grown plants is close. Those plants also have shown a fair amount of bacterial disease symptoms.
Rains have led to nitrogen deficiency symptoms on sandy sites. This is especially evident in sweet corn. Rains have also led to premature herbicide failure in some plantings.