Critical Limits of Zinc in Relation to the Growth of Pea (Pisum sativum L.) in Acid Soils of Imphal West District, Manipur (India)

Background: Zinc plays an important role in different plant metabolism processes like development of cell wall, respiration, photosynthesis, chlorophyll formation, enzyme activity and other biochemical functions etc. In spite of these various metabolic functions, no extensive field study was taken up in Manipur, India. Therefore, this study was aimed to find out the critical stages of Zn in soil and pea plant for Zn nutrition. Methods: In a pot culture experiment during 2017, the response of pea (Pisum sativum L.), cv. Rachna to Zn was studied on 20 acidic soils of Imphal West district, Manipur. In our investigation, physico-chemical properties of the various soil samples collected from different fields were analysed and various plant parameters were recorded grown in the pots. Result: Addition of Zn in the soils significantly increased the dry matter production and Zn uptake by the crop. DTPA extractable Zn was significantly correlated with dry matter yield of the plant (r=0.443*), Zn content (r=0.446*), Zn uptake (r=0.535*), Bray’s per cent yield (r=0.519*) and Bray’s per cent uptake (r=0.458*). The critical levels of Zn in soils and 50 days old pea plants below which response of pea to Zn fertilization may be expected are 0.69 mg kg-1 and 0.21 per cent Zn, respectively.