Late fall and early winter months bring certain climate and pest challenges. Learn more about two key threats to producing premium produce and the best strategies for heading them off.
Be on the Lookout for Leafminers
Serpentine leafminers can be a formidable cool‑season foe in tomatoes, peppers, snap beans and cucurbits at this point in the season, causing damage that can significantly reduce yields. With a life cycle as short as 20 days during warmer periods, you may face multiple generations in a season.
Most damage is caused by leaf‑feeding larvae. Their telltale mines, or runs, which are first visible on lower leaves, limit photosynthesis, cause early leaf drop and create wounds that let in bacterial and fungal diseases.
For tomatoes and other crops, DuPont™ Coragen® insect control powered by Rynaxypyr® (Group 28) provides exceptional control of leafminer (larvae), as well as major worm pests and suppression of whitefly nymphs. (Coragen® is labeled for control of Liriomyza species except suppression only for L. huidabrensis and L. langei.)
The best resistance management strategy for leafminer includes applying the highest rate of Coragen® (5 fluid ounces per acre) split into two drip applications at 3 to 5 weeks and 5 to 7 weeks after planting. If two drip applications of Coragen® are used, do not apply another Group 28 product at any time before or after them.
To control leafminer and a broader spectrum of costly sucking and chewing pests, foliage‑feeding thrips and whitefly in cucurbits and vegetables, apply DuPont™ Verimark® insect control as an at plant or early to mid‑season drip chemigation control option or Exirel® insect control in a foliar application. Both are powered by Cyazypyr® and classified as Group 28 insecticides.
Prevention is Best Strategy Against Powdery Mildew in Strawberry Crops
As late‑fall humidity increases, powdery mildew (Sphaerotheca macularis) poses a big threat to your strawberry crop. Powdery mildew loves warm, humid weather, but can infect plants even in relatively dry conditions. Once you spot small white patches on lower leaves, the disease has already gained a foothold and will progress rapidly.
A preventive fungicide application is always best. DuPont™ Fontelis® fungicide (Group 7) has outperformed competitive products in providing effective control of powdery mildew on strawberries. With a single mode of action, Fontelis® is a good rotation partner as part of a resistance management plan to control key diseases, including botrytis.
Two applications of Fontelis® at 16 ounces per acre, 7 to 14 days apart, deliver fast‑acting, lasting protection that’s both preventive and curative. A higher rate of 24 fluid ounces per acre is recommended under heavy disease pressure; don’t exceed 72 fluid ounces per acre per year. Fontelis® rapidly penetrates plant tissue, is rainfast within one hour and has no preharvest interval for strawberries.
Always read and follow all label directions and precautions for use.
DuPont™ Fontelis® fungicide; and DuPont™ Coragen®, Exirel® and Verimark® insect controls are not available in all states. See your local DuPont sales representative or retailer for details on availability.
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