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A few places in southern and northwestern Iowa have already reported twospotted spider mite populations with prolonged feeding in soybean this year. I recommend scouting corn and soybean fields for mite infestations because they thrive in hot and dry conditions. The U.S. Drought Monitor estimates about 80 percent of Iowa is abnormally dry or in a severe drought as of July 18, 2017.
Water is extremely important for crop production. When water becomes limiting to the plant it is important to understand how plants use water. We often hear the term evapotranspiration (ET) in relation to plant water demand. ET is a combination of soil water evaporation (E) and water used by the plant during transpiration (T). Soil evaporation is the major loss of water surface and typically is higher after rain and under high temperature conditions.
Dry conditions in some areas of Iowa this summer are resulting in quite variable corn growth and production potential. Some livestock producers are considering harvest of corn damaged by drought conditions for silage. Corn silage harvest results in more phosphorus (P) and potassium (K) removal than grain alone because almost the entire plant is harvested. The increased amount removed with silage differs for P and K because the relative amount of P and K is different in corn vegetative parts than in grain.
Bacterial leaf streak was confirmed for the first time in Iowa and other states in 2016. There is not a lot known about the disease but researchers at Colorado State University, Iowa State University, Kansas State University and University of Nebraska are collaborating to understand the disease and its impact on corn with partial funding through the Farm Bill.
