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.
Tomato spotted wilt. Plants show a variety of symptoms depending on when plants are infected; young plants show necrotic streaks or spots along with leaf distortion; older plants show yellowing and bronzing on the foliage, stunt and wilting from the apical tissue to the lower plant parts.