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.
Regardless of the issue, whenever there are yellow leaves on tomato plants, it warrants a thorough check as to what the problem could be. You never know what you will run across, and it could be detrimental not only to your tomato plants with their yellow tomato leaves, but to the rest of your garden as well.