RELATIVE EFFICACY OF METHODS OF ZINC, MANGANESE, IRON AND COPPER APPLICATION TO POTATO (SOLANUM-TUBEROSUM)

A field experiment was conducted during 1986 and 1987 with 'Kufri Jyoti' potato (Solanum tuberosum L.) to study the relative efficiency of zinc, manganese, iron and copper applied through 3 methods. The methods were soil application at the time of planting, spray of the crop at 50 and 70 days after planting, and soaking of seed tubers for 3 hr in micronutrient solution. The tuber yield increased significantly with the application of Zn by all the methods. But response to Mn was observed only when applied as spray with 0.2% manganese sulphate solution and to Cu when the seed tubers were soaked in 0.05% copper sulphate solution for 3 hr before planting. Application of Fe did not show any significant effect on the yield by any method of application. Maximum yield of 22.7 tonnes/ha in 1986 and 26.0 tonnes/ha in 1987 was obtained with the application of Zn by soaking seed tubers in 0.05% zinc sulphate solution for 3 hr. Maximum mean uptake of Zn, Mn, Fe and Cu by potato was 151, 271, 1 460 and 37.6 g/ha respectively.