Deficiency of Zinc in Poplar Nursery and Plantations in Punjab and its Amelioration

Light textured soils having low organic matter and nutrient content in the soil are prone to nutrient deficiencies in the plants growing on such soils. Zinc deficiency symptoms were observed in poplar plantations and nurseries, having soil deficient in organic matter and nutrient contents in Ludhiana District of Punjab on such soils. The deficiency was exhibited by development of irregular interveinal chlorosis of recently matured leaves along the margins that extends towards base of leaves. The deficiency was ameliorated by soil application of 25 g/plant Zn (through ZnSO₄.7H₂O) in 1 year old plants, 40 g/plant Zn in 2 years old plants and 30 kg/ha Zn in 4.5 years old plants. Application of 20 kg/ha Zn was sufficient for eradicating Zn deficiency in nurseries. Deficiency could be cured by 5-6 weekly sprays of 0.5 per cent ZnSO⁴.7H²O (alongwith half the quantity of unslaked lime) in the solution volumes of 1 l/tree for one year old trees, 2 l/tree for 2 year old trees and 250 l/ha for nursery. The micronutrient (except Fe) content of the recently matured normal leaves (Zn: 29.2-38.6 mg kg^-1) was higher than the deficient leaves (Zn: 25.2-28.4 mg kg^-1) taken from same position on branch or stem of trees. It was suggested to apply Zn at the planting time of poplar that can meet the requirement of plants throughout its growth.