My tomato plants are growing under cover and yesterday I stripped off some leaves that were damaged with brown dead spots, there were also some unhealthy looking flowers. Also I have noticed a white coloured film of mold (?) growing on the canes, which is not surprising considering the warm humid environment of the greenhouse. So I have bought a box of dithane sachets, although I only want to use it if I really have to. I have read the pack and it sounds quite toxic, how dangerous is it? I don't want to be eating 'dithene tomatoes' although should I spray them as a preventative measure under the circumstances that I have mentioned?
What chemicals do supermarket suppliers use?