Boytrytis on tomato

Botrytis on fruit

Updated: May 16, 2024
By Benjamin Beale

Botrytis in High Tunnel Tomatoes

Boytrytis on stem and leaves of tomato plant
Botrytis on Stem and Leaves

Botrytis (Gray Mold) is beginning to show up in high tunnel tomatoes. The same organism can cause losses in greenhouse ornamentals and strawberries. Gray mold is caused by the fungal pathogen Botrytis cinerea. Botrytis thrives in cool temperatures and high humidity environments, which have been plentiful this year. Botrytis can produce a tremendous amount of spores, especially on old or dying plant tissue. Removing all diseased plant parts, old flowers and infected fruit will reduce the amount of inoculum available to spread to other plants. This material should be burned or taken far away from the field. Sunshine and higher temperatures are what we really need to decrease the amount of gray mold. Increasing air circulation and venting the high tunnel as much as possible will also help. Fungicides may be needed to reduce losses form Botrytis. Many of the same fungicides that are effective on Botrytis are also effective on timber rot. Fungicide resistance issues have been reported with Botrytis in both strawberries and ornamental plants. Good coverage with adequate spray solution is essential.

Products recommended for control of Botrytis in tomatoes include:

  • fluopyram + Trifloxystrobin (Luna Sensation)
  • fluopyram + Pyrimethanil (Luna Tranquilty)
  • fluopyram + difenoconazole (Luna Flex)
  • boscalid (Endura) • chlorothalonil (Bravo or various others)
  • cyprodinil + fludioxonil (Switch)
  • pyrimethanil (Scala) • difenoconazole +cyprodinil (Inspire Super)
  • pydiflumetofen + fludioxonil (Miravis Prime)
  • fluxapyroxad + pyraclostrobin (Priaxor Xemium)
  • penthiopyrad (Fontelis) disease suppression only.

This article appears in Volume 15, Issue 3 of the Vegetable and Fruit News.

Vegetable and Fruit News is a statewide publication for the commercial vegetable and fruit industries and is during the growing season from April through October. Subscribers will receive an email with the latest edition.