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.
Remove the Bottom Leaves. Once your tomato plants reach about 3 ft. tall, remove the leaves from the bottom 1 ft. of stem. These are the oldest leaves and they are usually the first leaves to develop fungus problems. As the plants fill out, the bottom leaves get the least amount of sun and air circulation.. Once your tomato plants reach about 3 ft. tall, remove the leaves from the bottom 1 ft. of stem. These are the oldest leaves and they are usually the first leaves to develop fungus problems.