Statewide
Dr. Tony Keinath reports, “Basil downy mildew was found in mid-June in Charleston. Symptoms start as faint yellowing of leaves, which eventually show brown spots surrounded by yellow areas. To see the spores, look on the bottom of a symptomatic leaf. Sometimes it helps to hold the leaf up to a light source (but don’t look directly into the sun). Seeing spores is useful to rule out nutrient deficiency or sunburn on leaves. I do not know of any cultivars that truly are resistant or any organic biopesticides that are effective. Once downy mildew spores arrive in South Carolina, the disease will be present until frost kills the basil host.”
Basil downy mildew symptoms on the upper side of the leaves.
Dr. Tony Keinath, ©2021, Clemson Extension
Basil downy mildew spores developing on the underside of a leaf.
Dr. Tony Keinath, ©2021, Clemson Extension
Coastal
Zack Snipes reports, “Crops are still looking good. Typically, July 4th week is our busiest week in the field. One thing I saw this past week in some melon fields was crown decline. Crown decline is characterized by a yellowing of the crown leaves, which makes the plant look weak overall. The disease can be mistaken for a nutrient deficiency. This disease is important to diagnose because yields can be reduced, and fruit quality can be impaired at the middle to end of the season, which can impact your bottom line. I am seeing some gummy stem blight and anthracnose in watermelon right now as well.
Crown decline appears late in the season and can be confused with a nutrient deficiency.
Zack Snipes, ©2021, Clemson Extension
Midlands
Justin Ballew reports, “Things are progressing well in the midlands. Temperatures have been pretty mild, and we saw about half an inch of rain at my house Thursday afternoon. It looks like Tropical Storm Elsa will be coming through Thursday, so plant diseases will continue to be our major issue for at least a little while longer. I’ve seen plenty of downy mildew, powdery mildew, anthracnose, and bacterial spot over the last week. Japanese beetle numbers are pretty high right now also.”
Japanese beetles feeding on developing muscadines.
Justin Ballew, ©2021, Clemson Extension
Pee Dee
Tony Melton reports, “Sweet potato vines are covering the beds. We’re starting to harvest processing tomatoes. We’re planting fall butterbeans and peas and picking processing peppers for the second time.”
