Effect of Zinc on Sorghum Growth, Yield and Seed Zinc Content

In an attempt to study the relationship between seed zinc content and seedling vigour, hundred rabi sorghum genotypes were raised during rabi 2009-10.The genotypes at 30 DAS were categorized as low,medium and high vigour types based on drymatter accumulation.In high vigour genotypes the total dry matter ranged from 10.21-12.35g and in medium it ranged from 9.07-10.19g and in low vigour ranged from 6.25-8.84g plant-1. High vigor genotypes had higher zinc content 3.13-4.49 and low vigour types 1.96-2.66 mg100g-1. Thus there was correlation between seedling vigour and seed zinc content. To enhance the seed zinc content in selected genotypes in the field, zinc sulphate @ 10 kg/ha in combination with organics (1t/ha) at the time of sowing increased seed yield by 23% and seed zinc content by 23.6%.Root and shoot growth of sorghum increased considerably due to addition zinc at early stage.Low zinc types responded higher than high vigour types.Thus, zinc has differential response in sorghum genotypes based on vigour and growth.Therefore it is concluded that high vigour types are better for higher response to zinc, seed zinc content and yield too.