Nitrogen deficiency-Wine Grape

Symptoms
The older leaves become pale green or yellow, growth is clearly stunted. Young shoots, petioles and cluster stems become pink or red, regardless of the cultivar. Under drought conditions, the leaf margins roll slightly upwards, wilt and dry up. At severe deficiency, necrotic areas develop on basal leaves, and older leaves may wither and die off.

Reasons
Nitrogen deficiency Water shortage and some injuries of roots or trunks caused mechanically or by parasites that hinder the absorption and transport of nutrients lead sooner or later to stunted growth and lighter colored leaves, which may be confused with N deficiency.