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Reports of Goss's wilt have been coming in hard and fast this past week. The disease appears to be widespread north of I-80. Despite the hot, dry weather, the disease has progressed rapidly in the field.
By William Edwards, Department of Economics
Some Iowa corn and soybean producers are facing substantial if not complete crop losses due to flooding. In particular, many acres of crops in the Missouri River Valley have been under water for a month or more this year. Fortunately, nearly 90 percent of Iowa's corn and soybean acres are protected by multiple peril crop insurance.
The Iowa Drainage School on Aug. 23-25 near Nashua will address issues related to properly designed and operating drainage systems.
Producers have research findings from soybean trials and a simplified economic analysis to consider when deciding whether to make insecticide or insecticide-fungicide tank mix applications to soybeans.
Keep scouting corn fields. The weather the last two weeks has been favorable to several diseases.
By Roger Elmore, Department of Agronomy
Very hot days and warm night temperatures the last couple of weeks concern agronomists and corn growers. Unfortunately, this period of hot weather occurred during tasseling and silking. However, the USDA-NASS July 25th Iowa Crops & Weather report indicates that 80 percent of the crop was still in good to excellent condition. Ninety percent of the crop had tasseled and 75 percent silked — both slightly behind last year but ahead of the five-year average.
Although some parts of Iowa have had adequate moisture, other areas could use some rain. Drought stress combined with high temperatures is good news for field crop pests like grasshoppers and spider mites. If your area is hot and dry, consider scouting fields now and throughout August.
Growers and crop consultants are encouraged to scout corn and soybean fields for Japanese beetles this year.
The first symptoms of the disease are usually found on more compacted and low areas of the field and seen on the leaves of infected plants as scattered, yellow spots between leaf veins.
A week-by-week index showing relative crop risk according to the interaction of temperature and precipitation has proven to give a realistic picture of localities with poor and areas with better than usual crop yield.
