Fungicide Spray Schedule for Tobacco Transplant Production

Fungicides are an important tool for managing diseases in tobacco float beds, and getting the best results from these inputs hinges on using each product at a time when it will have the most impact in preventing a particular problem.  The following is a suggested schedule for timing the applications of products labeled for diseases in tobacco float beds.  The emphasis is on preventive use, and the timings are based on an 8-week transplant cycle (seeding to useable plant). 

Suggested Spray Schedule

2 to 4 Weeks after Seeding 
When roots of plants emerge from trays and enter float water, apply Terramaster EC at 0.7 to 1 fl oz/100 gal of float water for control of Pythium root rot.  Make a follow-up application of Terramaster at 1 fl oz/100 gal of float water no earlier than 3 weeks later (see below). 

3 to 4 Weeks after Seeding 
When plants have reached the size of a dime, apply Manzate Pro-Stick for suppression of Rhizoctonia damping-off and target spot.  The rate is 0.5 lb/100 gal of water (equivalent to 1 tsp/gal).  Use 3 gal of spray solution per 1000 sq. ft of bed (~400 trays); apply as a fine mist to ensure good foliar coverage. 

5 to 6 Weeks after Seeding 
The first time plants are clipped:

•  If target spot is not present, continue with Manzate Pro-Stick; increase spray volume to 6 (or more if needed) gal/1,000 sq. ft.  Don’t exceed 12 gallons of spray volume per 1,000 sq. feet (even on the largest plants).
•  If target spot is active, substitute Quadris for Manzate at a rate of 0.14 fl oz/1000 sq. ft of bed.  This is the equivalent of 4 cc (~1 tsp), and should be diluted in 4 to 5 gallons of water before dispersing as a fine spray.  One application of Quadris is permitted on tobacco seedlings in float beds. 

• Make follow-up application of Terramaster EC at 0.7 to 1 fl oz/100 gal of float water.
• If Quadris was not applied earlier, make one application of this fungicide at the second clipping.