Iodine bio-fortification in leafy vegetables cultivated under different agroclimatic zones of assam

North eastern region of India is known as iodine deficient area and the population is prone to dreaded and endemic disease like goiter. Plant biofortification with iodine can increase in the concentration of the element in edible part of the plant that efficiently improves the consumer’s health. Leafy vegetable was found to have the strongest capability in iodine enrichment through biofortification. An experiment was carried out for two consecutive years to study iodine bio fortification in the form of KI and KIO3 in spinach and cabbage grown in different agro climatic zones of Assam. Five dosages of KI and KIO3 i.e.1.0 mg kg-1; 2.0 mg kg-1 ;3.0 mg kg-1;4.0 mg kg-1 and 5.0 mg kg-1 was applied in foliar and soil along with recommended dosage of organic (Vermicompost) and inorganic(NPK) fertilizer. Foliar application of KI @ 4.0 mg kg-1 showed maximum iodine content during initial year of cultivation (12.24 mg kg-1) which was found to be reduced in successive year (11.66 mg kg-1). The same trend was found in cabbage cultivation also. This may be due to the absorption of iodine by the growing crop during initial year of cultivation. Maximum value was recorded @ 3.0 m g kg-1 when iodine was applied in the form of KIO3 in both spinach and cabbage cultivation. However, iodine concentrations in soil solution were generally higher in iodate treatments compared to iodide in both spinach and cabbage. Low iodine concentrations in soil solutions in treatments with iodide may be due to substantial iodine volatilization. Results showed that foliar application is more effective in biofortification than soil application. It was also observed that iodine accumulation in foliar application was comparatively more under agro forestry than in open condition. This concludes that uptake of iodine by plants grown in soils is dependent on the availability of iodine in the soils, which is essentially governed by adsorption– desorption processes in soils.