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.
There are two primary fungus diseases that can produce black spots on tomato plant leaves: Septoria leaf spot and Alternaria leaf spot, also known as early blight. Septoria and Alternaria differ slightly in appearance and prefer slightly different weather climates.
The saliva causes yellowing tomato plant leaves, and often makes the veins turn purplish. The stems of the plant will take on a zig-zag appearance. Once the saliva has taken over the tomato plant, it is difficult to save. For best results, dust the leaves with sulfur as soon as you notice symptoms.