Tomato Fungal Diseases

So far two fungal diseases have hit my tomatoes. Powdery mildew and tomato leaf spot. Powdery mildew is a common visitor to my farm. But this is the first year I've seen leaf spot. Wow, it's always something new when gardening in the tropics. I find it strange that it isn't the same diseases and pests year after year. Instead, the problems seem to cycle through, then reappear again years later. Well......except for the common things like aphids and stink bugs and powdery mildew. These last three also are cyclic, but not a year goes by that I don't see them on the farm one place or other, one time or another.

Powdery mildew has always been a headache. So I try growing veggie varieties that claim to have some resistance. That helps. I've tried a number of sprays that people suggest. I never had much luck until I learned that prevention was the key. Once powdery mildew is there, you can't cure it. But prevention works fairly well. 

Both powdery mildew and leaf spot. 

I've tried a number of different "natural" sprays. This year I've been using sulfur spray and it's worked best of all the sprays I've tried. But to be fair, this is also the first year I've been spraying as a preventative, not a cure. So I'll need to experiment with the other sprays to see if they work as well as sulfur for prevention. Once a week I've been looking over the plants, removing any infected leaves. Then I spray. The tomatoes are growing in a greenhouse, so rain is not an interfering factor. This factor may be the main reason the sulfur is working. It simply isn't getting washed away. 

Tomato leaf spot is a new one for me. It too is a fungal disease. I noticed that some tomato varieties are more resistant to it than others. Indigo Cherry Drops is super susceptible. Since I haven't been overly wow'd by this variety, I opted to simply remove the plants. Less plants for me to deal with. Of the remaining plants, I removed any leaves that had leaf spot and then sprayed sulfur. 

A bad case of tomato leaf spot. 

Whenever I see diseases stressing the plants, I'll add more fertilizer to boost the plant growth. In this case I've been using extra urine or compost tea in the irrigation water and applying fresh grass clippings as mulch. I can't say for certain that this helps, but I have a feeling that it does.