Using Fungicides On Tomatoes
9 Dec
Tomatoes can be seriously affected by disease, particularly in warm wet climates. It is important to monitor established plants regularly and act quickly if you see any disease symptoms. Disease may be caused by fungi, bacteria and viruses.Every country has its own list of government registered fungicides for different crops. Suppliers of these chemicals have to prove that they work, and usually that they will not cause undue damage to the grower and the environment.The list of registered fungicides for home gardeners is quite small and in the case of tomatoes revolves around the use of two in particular. The “active” ingredient of one is mancozeb and the other is copper. Although every country and reseller usually has a different commercial or selling name for it’s fungicides, in most cases the “active” chemical is the same.Mancozeb is the active of products often used for leaf spotting diseases. Copper-based chemicals can also be used for leaf spotting diseases, but are best for bacterial diseases which mancozeb will not control. These chemicals should be applied prior to the plant getting the diseases as they will not control diseases that have already started on the plant.Fungicides are best applied prior to rain, and then following rain before the appearance of disease. Fungicides will not control bacterial wilt-type diseases as well as some fungal wilts. However there are fungicides available for Phytophthora Root Rots.Viral diseases are usually controlled by controlling the pest and practising good hygiene.
Chapter 10 of our book How to Grow Juicy Tasty Tomatoes contains 11 fully illustrated pages of pest and disease information, including symptoms and control recommendations.