Disease Management for High Tunnel Spring Tomatoes in Kentucky

 

Disease Management for High Tunnel Spring Tomatoes

By Dr. Nicole Gauthier and Dr. Rachel Rudolph

 

 Example management schedule assuming:

Week 1 (~April 1) transplant

Week 9 (~June 15) harvest

Week 16 (~Aug 15) crop termination

 

Preplant

If tunnel has a history of timber rot (Sclerotinia spp), apply Contans pre-plant (see label)

Rotate out of tomato on a 3-year schedule, especially for sites with history of soilborne diseases

Space plants for maximum air circulation

 

Weeks 1-8 Vegetative Growth

Maintain RH <70% by opening end or side walls for air circulation! This is the most critical step for disease prevention and control.  If above 50 degrees F outside, it is safe to open the tunnels without damaging tomatoes. Install at least one humidity meter in each tunnel.

Sucker and prune tomato plants early while suckers are small to avoid creating open wounds. Use clean tools.

Practice good sanitation, remove diseased or senescing tissue regularly, remove clippings from tunnel.

Use preventative fungicides for bacterial and fungal diseases:

·         Low input:  Every week or two weeks (choose one or rotate)

o   OxiDate or ZeroTol or

o   OSO + copper or

o   Dexter Max (or mancozeb + copper)

·         Mid/high input:  Every week or two weeks, rotate among

o   Dexter Max (or mancozeb + copper)

o   Fontelis or Quadris Top*

·         Add targeted products, as needed, based on diagnostic results.

·         For timber rot, use Fontelis or Endura during April and May according to label.

·         For Botrytis gray mold, target applications in April and May.

 

Weeks 9-15 Harvest

Maintain RH below 70% all season.

Practice good air circulation. Unless there is extreme wind, the tunnel should be pretty much open all the time during this time period.

Sanitation is critical.

Continue fungicide applications:

·         Low input, every two weeks; mid/high input, every week

o   OxiDate or ZeroTol (0d PHI)

o   Optional, add Fontelis or Quadris Top* into rotation (0d PHI)

·         For leaf mold, target applications June/July through harvest

 

*Maximum 5 applications per season

Always read labels for specific use instructions

See spray guides for efficacy data.

Reminder:  From a pesticide application standpoint, high tunnels are considered greenhouses according to the Kentucky Department of Agriculture; use only greenhouse-approved products. If the label says that it is not permitted for use in a greenhouse, it is not permitted for use in a high tunnel.