"Fumigation Tips for
|
The use of methyl bromide has been shown to be very effective in reducing disease in tobacco greenhouses. The recommendation to fumigate trays with methyl bromide is based upon research which has shown that the two most important diseases in the greenhouse, Rhizoctonia (Target Spot) and Sclerotinia (Colar Rot), are not effectively controlled by dipping in chlorox or other sanitation solutions. The source (inoculum) of Target Spot is embedded in the styrofoam of the trays and the inoculum for Collar Rot develops later in the season and comes from outside of the greenhouse. The recommended steps for this practice are listed below.
1) Trays should be stacked at a height no greater than five feet with each layer being crisscrossed. This is recommended to enhance the infiltration of the methyl bromide gas. Trays should be covered with perforated plastic.
2) Apply 3 pounds of methyl bromide per 1000 cubic feet of trays. Cubic feet is calculated by the following formula: length (ft.) times width (ft.) times depth (ft.) Trays should remain covered for 48 hours and then aerated for at least 24 to 48 hours. The temperature at the point where the gas meets the fumigated area should be at least 50 degrees.
3) To avoid damage due to methyl bromide, trays should not be allowed to contact the liquid directly. Some means to deflect this stream should be provided. A gaseous streat would not be expected to cause this problem.
In other experiments, styofoams trays which were steamed at a temperature of 140 degrees F for at least thirty minutes was also found to be effective in reducing these two tobacco greenhouse diseases.
Distributed in furtherance of the Acts of Congress of May 8 and June 30, 1914. Employment and program opportunities are offered to all people regardless of race, color, national origin, sex, age, or disability. North Carolina State University at Raleigh, North Carolina A&T State University, U.S. Department of Agriculture, and local governments cooperating.