The low chemical activity of the inert gases is due to the fact that their outermost, or valence, electron shell is complete, containing two electrons in the case of helium and eight in the remaining cases.
Often only one side of a plant is affected at first, but symptoms eventually spread. Tomato Leaf SpotâSeptoria lycopersici Fruit is not affected, although sunscald can be a problem due to foliage loss. Numerous brown spots on leaves, each about 1/16 inch in diameter. They do not have a yellow halo and they do have black specks in the center. First symptoms are usually on lower leaves after the first fruit sets.
Plum and paste varieties are most commonly affected. Cure for Tomato Leaves Curling Although physiologic effects for tomato leaf curl do not affect the overall growth or crop yields of plants, when the tomato leaf curling is due to a viral infection, removal of the infected plants is necessary.owever, learning to recognize the sign and causes of curling tomato leaves can make it easier to both prevent and treat the problem. Tomato Plant Leaf Curl Virus Curling tomato leaves may be a sign of a viral infection.