Wayne County IPM Notes
(From the Week of July 12 – July 18)
Frank Becker, OSU Extension Wayne County
Squash Bugs are starting to lay large numbers of egg masses on summer squash, gourds, and pumpkins. Large numbers of squash bugs feeding can cause leaves to yellow and eventually die which can significantly reduce yield.
Cucumber Beetles are feeding again, primarily on young, recently transplanted squash. This is a important time to work on control of cucumber beetle as with young plants, the cucumber beetles can cause severe damage, stunt the growth of the plant and may lead to plants going down later with bacterial wilt.
Potato Leaf Hoppers (PLH) still have very high populations in several crops this year. PLH cause “hopper burn” on the leaves on which they are feeding. I have seen this damage to potatoes and green beans.
Japanese beetles are feeding in basically every crop that I scout. Sweet corn growers should be especially wary of the Japanese Beetles feeding since one of their target areas on sweet corn is the silk. The beetles can clip the silks and affect the success of the pollination. More on Japanese beetles and other sweet corn pests.
Downy Mildew has been confirmed, again, in Medina County. Cucumber growers should have started a spray program for the cucurbit downy mildew.
Powdery mildew is starting to show up on cucurbit crops around the area. If older plantings of summer squash are heavily infested and you are no longer harvesting from those areas, it would be of your best interest to terminate that crop so that you are not allowing the powdery mildew to have a place to thrive. This is especially important if you have younger, successive plantings of summer squash nearby.
Some field tomatoes are showing symptoms of early blight. Early blight is a common tomato disease and happens when soil is splashed up onto the older, lower leaves. If not treated, early blight can cause significant defoliation of a plant.
In melon patches, specifically in cantaloupe, there is some Alternaria leaf blight showing up. This disease primarily affects the foliage but if the infection is severe enough, it may also infect the fruit.
Although not technically a disease, blossom end rot is still affecting a lot of crops. This is technically a deficiency of calcium in the plant but not necessarily in the soil. The best way to attempt to prevent further issues is to have consistent moisture to the plant and provide an environment conducive to adequate nutrient uptake.
I have started to see grape berry moth larvae feeding in grape clusters. Scouting grapes and carefully assessing the grape clusters can help you determine management needs. Infestations of grape berry moths are typically higher along the borders, and near woods or hedge lines as compared to the interior of the vineyard.
Spotted Wing Drosophila numbers are still increasing. The trap counts were up again this week, with all the traps being in blueberry patches.
Codling Moth and Oriental Fruit Moth trap counts were low again this week and showed very little activity.
I am still seeing red mites in apple orchards throughout the county. Feeding by large populations of red mites can cause leaves to “bronze” and when left uncontrolled, this heavy feeding could result in leaf drop and a reduced size and quality of the crop. This hot and dry weather has been ideal for the red mite populations to get established in orchards.
Japanese beetles are feeding across the spectrum of fruit crops that I am scouting. I have noticed heavy damage primarily occurring on ripe blueberries and on grape leaves. Left uncontrolled, the Japanese beetles can cause severe defoliation in grapes.
Alternaria leaf blotch can be found on some apple trees right now. This can be made worse by red mite infestations. With high populations of mites and the leaf blotch, severe defoliation can occur.
Apple and peach growers should continue their spray programs to manage fruit rots and diseases such as flyspeck and sooty blotch.
Grapes should be starting to get some color to them as the clusters are starting to increase in size. At this point, most varieties of grapes should be resistant to black rot. Growers with varieties of grapes that are not resistant to downy mildew should consider a spray program. Find more here on grape diseases.