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.
My plants are dying from the ground up. I have tons of fruit on the plants but I'm afraid the plant won't live long enough for the fruit to ripen. I'm at a loss yet again this year. Q: My tomato plants have black spots all over the leaves and stems and although I keep trimming them off, it persists.