Deficiency symptoms of nitrogen and potassium are visible first in Senescent leaves, Roots, Buds, or Young leaves?

Generally, nutrient deficiency in the plant occurs, when a nutrient is insufficient in the growth medium and / or cannot be absorbed and assimilated by the plants due to unfavorable environmental conditions. The characteristic deficiency symptom of nitrogen is the appearance of uniform yellowing of leaves including the veins, this being more pronounced on older leaves. The leaves become stiff and erect. In dicotyledonous crops the leaves detach easily under extreme deficiency condition. Cereal crops show characteristics 'V' shaped yellowing at the tip of lower leaves. Under potassium stress condition, yellowing of leaves starts from the tips or margins of leaves extending towards the center of leaf base. These yellow parts become necrotic (dead spots) with leaf curling.