Vegetable Disease Update – 9/18/18

  • Cucurbit downy mildew. All cucurbit growers should scout their fields on a regular basis and inlcude a downy mildew specific fungicide to their weekly maintenance sprays.
  • The 2018 FRAC Table for Cucurbit Downy and Powdery Mildew Control in the mid-Atlantic Region can be found and downloaded for FREE here and is essential for developing control strategies for both diseases.
  • Bacterial stalk rot in sweet corn has been reported.
  • Downy mildew has been reported in bok choy. Cole crops, as well as leafy greens, need to be scouted on a regular basis and preventative sprays applied as long as wet weather continues.
  • Pepper anthracnose has been reported. If found in field, weekly fungicide maintenance sprays are needed. Abandoned fields should be mowed down immediately.
  • Alternaria leaf spot has been reported on broccoli.
  • Anthracnose has been reported in turnip.
  • Late blight has been reported on tomato in Western PA. There have been no reports of late blight in the immediate region.
  • Bacterial leaf spot and Phytophthora blight and fruit rot remain active in pepper and cucurbit crops.
  • Cercospora leaf spot has been reported on swiss chard and beets.
  • A nice article by Dr. Beth Gugino, Penn State, on gray mold and late blight in high tunnel tomatoes can be found here.
  • Remember, copper applications on hot days with high relative humidity can cause phytotoxicity on a number of crops.
  • Basil downy mildew is being reported. Recent weather has been ideal for its development. For more information on Rutgers newly-released DMR sweet basils Obsession, Devotion, and Thunderstruck please click here. Follow the Rutgers Basil Downy Mildew Breeding Program on Instagram at #RutgersBasil