Description:
Nitrogen deficiency affects all the important crops. Nitrogen is essential for the vegetative stage of the plant, enhance the absorption of other vital elements and leads to high yields, so it is one of the most commonly applied fertiliser. The deficiency favored by sandy soils with low organic matter, by drought conditions and/or by intensive irrigation. Sometimes in grapes we can detect red petiols and veins.
Symptoms:
Leaves: Generalized chlorosis of older, fully developed leaves and then the symptoms move gradually to the upper young leaves. Veins are also chlorotic while the whole leaf become pale-green and then pale-yellow. Necrotic areas may appear on larger leaves. Sometimes young leaves are smaller in some crops
Stem: Stunted growth. Shoots become longer and thicker with large internodes
Fruits: Thinner edges ( curved and discolored) and deformation of cucumbers.
Hosts: Vineyard, tomato, cucumber, apples, barley,citrus, e.t.c
References:
https://www.yara.us/crop-nutrition/citrus/nutrient-deficiencies/nitrogen-deficiency-on-orange-citrus/
Panagopoulos., C. (2007) Diseases of fruit trees and vineyard. 4th Edition