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.
septoria leaf spot septoria leaf spot is a disease caused by the fungus septoria lycopersici according to iowa state university this is the most common foliar leaf disease in tomato plants small spots appear that initially look water soaked then develop gray and white centers with darker edges tiny black spots appear in the center of the spot as the disease matures lower leaves are infected first but the disease spreads to the top leaves over time this eventually causes defoliage of the plant