Field Update – 6/3/19

Statewide

Dr. Tony Keinath reports,”Powdery mildew was found on watermelon at the Coastal REC on May 30. Typical symptoms of powdery mildew on watermelon are distinct yellow spots, although the spots may be indistinct yellow blotches rather than round spots. The symptoms seen this week included more browning than is typical for the size of the spots, perhaps due to unusually hot weather.  To manage powdery mildew on watermelon and other cucurbits, click here. Powdery mildew-resistant cultivars of cucumber and cantaloupe are holding up well, but squashes with partial resistance to powdery mildew should be sprayed.”

Yellow spots include more browning than usual for powdery mildew. The hot weather probably contributed to this. Photo from Dr. Tony Keinath.

Coastal Region

Zack Snipes reports, “Another week without rain for most of the Lowcountry.  The irrigated crops that have gotten enough water and look great including tomato, watermelon, cantaloupe, cucumbers, and squash. We are at the beginning of tomato, melon, rabbiteye blueberry, and blackberry harvest.  Blueberry growers will want to look out for anthracnose fruit rot in harvested berries.  There is nothing that can be done this year but we can work on spray programs for next year.  The tomato crop looks great except for the usual bacterial wilt and southern blight.  I heard of a few hot spots of spider mites last week so scout regularly especially during this hot and dry period.”

Cantaloupe looking good in the Coastal region. Photo from Zack Snipes.

Anthracnose in blueberries. The photo on the right shows berries that were just picked. The berries on the left were picked 3 days prior to the photo being taken and stored at room temperature. You can see the orange spore masses on some of the berries. Photos from Zack Snipes.

Midlands

Justin Ballew reports,”Last week was another hot, dry week. It’s been 23 days now since we’ve had rain that amounted to anything more than a brief sprinkle. Irrigation systems are not getting much rest. Squash and zucchini yields have suffered some, most likely because bee activity decreases when it is extremely hot and dry. We have some blueberries that are suffering because the drip system is not able to keep up with the water demand. Other irrigated crops like sweet corn, tomatoes, peppers, and eggplant are looking fine. We need rain pretty badly, though.

Collards just outside of the reach of the end gun are wilting and the bottom leaves are drying out. Photo from Justin Ballew
Blueberries are showing signs of drought stress in the Midlands. Photo from Justin Ballew

Sarah Scott reports, “Things are busy and man has it been HOT! I’ve been speaking with Brett Blauuw, entomologist from UGA,  about what to expect when the temps dip back down to “normal” as far as the pest outlook is concerned and here are some notes from our conversation:

  • Scale insects tend to become inactive at temperatures greater than 90, but they will continue to develop at night when the temperatures dip back down. The activity should decrease compared to a ’normal’ spring where it’s in the 80s. We still have a couple of weeks before we see another peak abundance of scale crawlers.
  • Stink bugs don’t mind the heat much. The adults that emerged from overwintering are dying right now, so the numbers are declining but, they have laid eggs and the nymphs will be developing. In a couple of weeks we should expect another large number of BMSB adults. 
  • Plum curculio is also more abundant and active this year. Still catching adults down in Fort Valley, so that is another concern.
  • Thrips, unfortunately love hot, dry climates, so right now is the perfect weather for them. For organic producers, Entrust is an affective product.”
Squash bugs showing up on cucurbits in the Midlands. Photo from Sarah Scott.

Field Update – 5/28/19

Statewide

Dr. Tony Keinath reports, “Downy mildew has moved into south Georgia on cucumber and watermelon. Growers should have downy mildew fungicides on hand and be ready to spray cucumber, cantaloupe, and watermelon when rain starts in the lower half of the state. A preventative spray of mancozeb or chlorothalonil would be a good idea in the meantime. You can keep track of the spread of downy mildew here.

Despite the dry weather, anthracnose was found on watermelon in the Bamberg/Barnwell County area last week. All watermelons in the state should be sprayed with mancozeb as a preventative.”

Anthracnose lesions on watermelon leaf. Photo from Dr. Tony Keinath

Coastal Region

Zack Snipes reports, “It has been unusually hot for the month of May.  The current heat wave coupled with the lack of rain is really starting to have an impact on crops, even irrigated crops.  The tomato and melon crops look good but are starting to feel the intense heat and lack of rain.  I have seen very little disease and insect pressure on all crops.

Irrigated watermelons are looking great on the Coast. Photo from Zack Snipes.
Irrigated peppers wilting in the heat of the day. Photo from Zack Snipes

Midlands

Justin Ballew reports, “This past week was hot and dry. It felt more like July than May. It’s been over two weeks now since we’ve had any rain and irrigation systems are running a lot. In larger fields with overhead irrigation, we are seeing some wilting where the pivots aren’t getting around fast enough. Drip irrigated crops are looking good. Silks are starting to brown on the earliest planted sweet corn. Blackberry picking will begin soon and muscadines have begun blooming.

Collards wilting in between watering. Photo from Justin Ballew
Silks are turning brown on earliest planted sweet corn. Photo from Justin Ballew