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.
How to Control Black Spot on Roses. Controlling black spot on roses is crucial to any rose grower. Black spot is a fungal disease characterized by black spots on the upper side of leaves. Tending to occur in warm, wet weather, usually during wet summers, the leaves of infected roses turn yellow and fall off.