Actigard has not been evaluated on tomatoes in Oklahoma. I plan to do this during the spring at Bixby where bacterial spot is a chronic problem. The label for Actigard on tomato does warn that its use may lead to reductions in yield and recommends that growers try it on a trial basis. Trial reports on tomato from other states in 1999 generally showed enhanced bacterial disease control without yield reductions. Many growers produce vegetable transplants for their own field production or for sale.
Transplant health is critical for avoiding the introduction of diseases into the field.
Bacterial spot of pepper and tomato, bacterial speck of tomato, bacterial canker of tomato, black rot of crucifers, and watermelon fruit blotch are destructive diseases that are carried on seed. While only a small percentage of seed may be contaminated, greenhouse conditions are conducive to the development and spread of diseases because plants are often crowded together. Furthermore, bacteria may survive and spread on leaf surfaces without causing symptoms until after transplants are set. Practice sanitation in the greenhouse, especially when it is vacant. Kill all weedy vegetation growing in the greenhouse.