Statewide
Tom Bilbo reports, “When spider mites first invade and establish in fields, they will be distributed in a series of clustered hot spots, usually near field borders, especially near a dusty road. Two-spotted spider mites can develop at temperatures >50F, so the warm weather in the Lowcountry is allowing spider mites to reproduce and lay eggs. The current pre-harvest threshold for spraying an acaricide is when you see at least 5 mites/leaflet. This count is an average determined from collecting at least 10 leaflets (mid-tier on the plant) per acre, collected randomly throughout each acre. Check back next week for guidance on conserving/releasing predatory mites.”
A two-spotted spider mite next to an egg.
Tom Bilbo, ©2023, Clemson Extension
Midlands Region
Sarah Scott reports, “Along the Ridge, some areas received close to 5 inches of rain in the last week. With more rain expected, we are looking at very soggy field conditions. Peach trees are still being planted as workers are able to get into the fields. It seems the planting depth can be tricky with softer soils. We’ve noticed trees being planted a bit too deep, with the graft union covered by soil. Make sure workers are clear on planting depth and keep an eye on this.”
A peach tree planted too deep with graft union covered.
Sarah Scott, ©2023, Clemson Extension
Remove soil to expose the graft union to avoid issues with rot and tree decline.
Sarah Scott, ©2023, Clemson Extension
Upstate Region
Andy Rollins reports, “Peach growers are continuing to prune trees. Some are finding scale problems. The limbs appear grey and dingy looking compared with others. Upon closer inspection, you can notice hundreds of thousands of immobile scales covering the limbs and even in the tightest crevices between the limbs. They are feeding on the plant and slowly killing it. If you scratch the bark of smaller unaffected limbs, you’ll see a nice bright green cambium layer just below the bark. Oil sprays are critical for helping to control this pest but will perform better with insecticide added. Rates on the oil range from 2-4%, and higher water solution rates are preferred. If trees are pruned, 100-gallon coverage per acre is enough. Otherwise, specialists prefer you use closer to 200 gallons per acre.
Strawberry issues are similar to other reports. I have one grower with major deer damage. In his case, he will need to start fertilizing sooner, in mid-February, to try and recover the loss of plant tissue from feeding damage. Excessive rains cause the need for earlier than normal fungicide applications like captan or thiram, which can help as a deer deterrent.”
Thousands of immobile scales are feeding on and slowly killing this branch.
Andy Rollins, ©2023, Clemson Extension
