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.
1 Horn: tomato hornworm â dark blue, dark green or black; tobacco hornworm â red. 2  Markings: 3  tomato hornworm â eight, V-shaped white or yellowish strips across the torso.4  tobacco hornworms â seven, straight or diagonal white strips edged with black across the torso.5  Size: both can grow to be 3-4 inches long.hey feast on both tomato leaves and green tomatoes. Look for 1  â. stems missing leaves. 2  leaf wilt. 3  dark green or black pellet droppings (also called frass) on a lower leaf indicating the presence of a hornworm above.