The volume of flame, however, is increased by inert gas, and there is a proportionate diminution of the heating effect. Encyclopaedia Britannica, 11th Edition, Volume 11, Slice 3 Various. Nitrogen by itself is an inert gas, colorless and uninflammable. Scientific American Supplement No. 819 Various.
Tomato Spotted Wilt Virus. The tomato spotted wilt virus (TSWV) causes dark brown, purple or black spots on leaves. The spots can spread to the stems, causing cankers and streaks. The foliage begins to wilt once the disease spreads, and the leaves become stiff.
Alternaria alternate, or tomato early blight alternaria, is a fungus that can cause cankers and plant leaf spots on tomato plants. It normally occurs during hot weather when there has been a significant amount of rain and humidity.nce a plant is infected tomato early blight alternaria, a fungicide can be sprayed on the plant. This can help reduce the damage from the plant, but frequently this will only lessen, not eliminate the problem. The best way how to treat leaf spot on tomatoes is to make sure it does not occur in the first place.