VISUAL NUTRIENT DEFICIENCY SYMPTOMS IN SAPOTA (MANILKARA ACHRAS FORSBERG)
Visual symptoms of nitrogen, phosphorus and potassium deficiencies were induced in sapota (Manilkara achras Forsberg) seedlings grown under sand culture. Nitrogen deficiency caused highly reduced plant growth. Typical yellowing symptoms first appeared along the leaf margin and spread towards midrib in older leaves. Phosphorus deficiency resulted in short and thin plants with small dark upright leaves and gradually turn to purplish rusty pigmentation followed by early defoliation. Potassium deficiency caused irregular marginal chlorosis in recently matured leaves and gradually turn to blackish grey. The scorched leaves remained attached to the stem even after complete necrosis and drying. However, plant growth was not affected much due to potassium deficiency.
Nachegowda, V., Sulladmath, U.V. and Vijayakumar, N. (1992). VISUAL NUTRIENT DEFICIENCY SYMPTOMS IN SAPOTA (MANILKARA ACHRAS FORSBERG). Acta Hortic. 321, 566-573