Grasshoppers are common insects found across various environments, including agricultural landscapes. These insects are known for their ability to consume plant matter, which often brings them into contact with cultivated crops. This article explores the relationship between grasshoppers and corn plants, detailing how these insects interact with the crop.
Grasshoppers and Corn: The Connection
Grasshoppers do consume corn plants, making them a concern for corn growers. They are general feeders on many field-side plants and often move to cultivated crops when conditions are favorable, especially during dry periods when other vegetation becomes scarce.
These insects feed on various parts of the corn plant. Nymphs and adults will eat the leaves, often creating ragged holes and sometimes leaving only the midrib. They also consume silks, which can interfere with pollination, and chew on ear tips and developing kernels. In high grasshopper populations, they may even feed on stalks.
Impact on Corn Plants
The feeding activity of grasshoppers can significantly affect corn plants. Defoliation, characterized by chewed leaves and ragged holes, reduces the plant’s ability to perform photosynthesis. When grasshoppers clip or consume corn silks, it can disrupt the pollination process, leading to blank or partially filled ears.
Damage to the ear tips and developing kernels can directly reduce the marketable yield of the corn crop. In severe cases, extensive feeding can result in pruned ears or barren stalks. Beyond direct consumption, injury to the ears and pods can create entry points for pathogens, potentially reducing grain quality.
Protecting Corn from Grasshoppers
Managing grasshopper populations in corn involves several strategies, beginning with cultural practices. Tillage in the fall and spring can destroy grasshopper egg masses laid in the soil, reducing the number of nymphs that hatch. Controlling weeds in and around corn fields removes alternative food sources and shelter, to deter them from the crop. Some growers also employ trap crops, such as a border of tall grass, to attract grasshoppers away from the main corn crop.
Physical barriers offer protection for smaller corn plots. Row covers or metal screening can physically exclude grasshoppers from young plants. Unlike cloth covers, metal screening is more resilient against chewing mouthparts.
Biological controls utilize natural enemies to regulate grasshopper numbers. Various species of birds, wasps, ground beetles, and parasitic flies prey on grasshoppers. Additionally, natural pathogens, such as specific fungi, can infect and reduce grasshopper populations, particularly during wet years.
When infestations become severe, chemical applications might be considered. Insecticides can be applied, often as spot treatments along field margins where grasshoppers initially congregate. Consider the life stage of the grasshoppers and the severity of the injury when determining the need for intervention. Always adhere to product labels regarding application rates and pre-harvest intervals for safety and effectiveness.