Tomato Leaves - Every year, but this year seems worse, the bottom leaves on...
Tomato Leaves - Every year, but this year seems worse, the bottom leaves on my tomato plants turn yellow with brown splotches, then all yellow and ultimately all brown and withered. I cut them off and discard, and the plants on the tops seem healthy and I still get a lot of tomatoes. I've attached a picture of a leaf group in transition to its ultimate demise. I thought it might be early blight but it doesn't seem to have a concentric pattern, it's more blotchy. Also, I have my tomatoes staked to a sturdy fence, growing in well amended soil that is covered with landscape fabric, so the soil doesn't splash up on the leaves. What is causing this leaf damage, and can I correct it?
This may be a combination of early blight and septoria leaf spot. The life cycles are similar. Unfortunately, plants can still get early blight even with all the good measures you have taken.
Please read over the info on early blight in our "IPM Series: Tomatoes" to be sure you do each possible task, such as removing all infected debris at the end of the season: http://extension.umd.edu/sites/default/files/_images/programs/hgic/Publications/HG56%20IPM%20Tomatoe...
Fungicides cannot cure a fungal disease, but are preventative. Spray when you plant, or as soon as you see the first trace of the disease remove the infected part and spray. Keep in mind that fungicides have been discovered to be toxic to bees, so do not spray the flowers.
Now that the season is over I'm considering disposing of the diseased (early blight?) tomato plants by dumping them in our woods over two acres away. Is that far enough? what can I do to prevent this blight next year? Is it best to remove the black landscape fabric and till up the soil? Should I add anything to the soil to kill the fungus? Planting in another location on our property would be difficult.
The fungal spores overwinter in soil, on diseased plant parts, and on seed and can also be spread by animals, tools, and people. Plants become infected when leaves contact the soil, water is splashed on plants, or spores carried by wind and air currents land on plants. We don't have research information on the distance the spores travel. Your best bet is to chop up plants so they decompose faster or add plants to a hot compost pile.
You cannot easily rotate away from early blight. It's a ubiquitous disease in
Maryland. There is nothing to add to the soil, other than compost, which is rich in
microbial life that may help protect plants against disease by colonizing plat tissue surfaces
(out-competing or antagonizing pathogens).
Follow these management tips: