Disease Management for High
Tunnel Spring Tomatoes
By Dr. Nicole Gauthier and Dr. Rachel Rudolph
Week 1 (~April 1) transplant
Week 9 (~June 15) harvest
Week 16 (~Aug 15) crop termination
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
input: Every week or two weeks (choose one or rotate)
o OxiDate or ZeroTol or
o OSO + copper or
o Dexter Max (or mancozeb +
input: Every week or two weeks, rotate among
o Dexter Max (or mancozeb + copper)
o Fontelis or Quadris Top*
targeted products, as needed, based on diagnostic results.
timber rot, use Fontelis or Endura during April and May according to label.
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:
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)
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.