Agronomic Crops
Corn and soybeans are both being impacted by slug feeding. In most cases, corn will be able to outgrow the pressure from the slug feeding. Soybeans, however, are much more susceptible to being severely damaged by slug feeding, even to the point of significant crop loss. Slugs are best managed by avoidance and habitat reduction. Slugs thrive in heavy residue fields with minimal tillage disturbance. Later planting dates, when soils start to dry out, along with some tillage or residue management can help to prevent major impacts from slug feeding.
Black cutworm, Matthew Nussbaum photo.
Some corn fields are also being impacted by black cutworms. These caterpillars can do significant damage in young corn stands. We are reaching the end of their feeding activity in our area, but we will continue to monitor for other larva pests. Weed management is also important this time of year in agronomic crops. Being able to knock the weeds back until we start to get some canopy closure can help prevent the weeds from competing with corn or soybean plants for water, nutrients, and sunlight.
Alfalfa fields are showing good regrowth with minimal pressure from diseases or insect pests. There are some concerns with increasing aphid populations, along with the arrival of the potato leaf hoppers.
Vegetable Crops
The insect pressure on the area vegetable crops has continued without much fluctuation. In summary, the Colorado potato beetle larvae, along with flea beetles, continue to feed on potatoes, tomatoes and eggplant, we began to find tortoise-shell beetle feeding on the leaves of sweet potatoes, thrips are starting to feed in onions, aphids are continuing to feed in many crops, including peppers and tomatoes, slugs are feeding on sweetcorn, as are cutworms, cucumber beetles are all over cucurbit crops, and potato
Golden Tortoise Beetle on Sweet Potato.
leaf hoppers and bean leaf beetles have started to build population in green beans.
The warm and wet weather has led to some disease concerns, especially in lettuce. We have started to find heads of lettuce being affected by white mold. It is best to remove these heads of lettuce from the field to prevent further infection and soil infestation.
Small Fruit and Orchards
Our trap counts for CM and OFM were either 0, or low this week, with none of our trapping locations being near threshold. Most of the small fruit in our area is in fruit development, or fruit maturity. Strawberry harvest is fully underway at this time. We are seeing some slug feeding on strawberries, but very few other concerns at this time. Grapes are beginning to bloom, and depending on the variety, may already be in full bloom. Don’t forget to spray for black rot during this period.