Weekly Field Update
Clemson Extension agents provide updates in The South Carolina Grower this week about the status of various crops being produced throughout the state.
Statewide
Tom Bilbo reports, “If you grow strawberries then hopefully the question of the week last week was easy, and that it encourages you to scout your fields! The translucent spheres were two-spotted spider mite eggs on the underside of a strawberry leaf, and the white stippling on top of the leaf was the first obvious sign of a spider mite “hot spot.” When spider mites first invade and establish in fields, they will be distributed in a series of clustered hot spots, usually near field borders. Twospotted spider mites can develop at temperatures greater than 50 degrees Fahrenheit. 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 per leaflet. This count is an average determined from collecting at least 10 leaflets (mid-tier on the plant) per acre randomly throughout each acre. The best acaricides to use early in the season are those with activity against both eggs and nymphs/adults such as bifenazate (Acramite), cyflumetofen (Nealta), and acequinocyl (Kanemite). Avoid pyrethroids (Group 3). Check back next week for guidance on conserving/releasing predatory mites.”
Midlands
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 with softer soils, planting depth can be tricky. 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.”
Upstate
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 to them. Rates on the oil range from 2% to 4%, and higher water solution rates are preferred. If trees are pruned, 100-gallon coverage per acre is enough. Otherwise, specialists prefer growers to 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.”