Zinc Application Affects Tissue Zinc Concentration and Seed Yield of Pea (Pisum sativum L.)

A 2-year field experiment was conducted to assess the effect of applied zinc (Zn) on the seed yield of pea (Pisum sativum L.) and to determine the internal Zn requirement of pea with emphasis on the seed and leaves as index tissues. The experiment was carried out at two different locations (Talagang, Chakwal district and National Agricultural Research Centre (NARC), Islamabad) in the Potohar Plateau, Pakistan by growing three pea cultivars (Green feast, Climax, and Meteor). The soils were fertilized with 0, 2, 4, 8, and 16 kg Zn ha−1 along with recommended basal fertilization of nitrogen (N), phosphorus (P), potassium (K), and boron (B). Zinc application increased seed yield significantly for all the three cultivars. Maximum increase in the pea seed yield (2-year mean) was 21% and 15% for Green feast, 28% and 21% for Climax, and 34% and 26% for Meteor at Talagang and NARC, respectively. In all cultivars, Zn concentrations in leaves and seed increased to varying extents as a result of Zn application. Fertiliser Zn requirement for near-maximum seed yield varied from 3.2 to 5.3 kg ha−1 for different cultivars. Zinc concentrations of leaves and seeds appeared to be a good indicator of soil Zn availability. The critical Zn concentration range sufficient for 95% maximum yield (internal Zn requirement) was 42–53 mg kg−1 in the pea leaves and 45–60 mg kg−1 in the seeds of the three pea cultivars studied.