Which micronutrient deficiency causes 'khaira disease' in paddy (rice) crops?

💡 Solution & Explanation

Khaira disease in paddy crops is caused by zinc deficiency, which impairs enzymatic activities and chlorophyll synthesis, leading to yellowing of leaves and reduced yields. Other elements like boron, molybdenum, and iron result in distinct physiological disorders when deficient, such as heart rot or interveinal chlorosis, but do not trigger khaira symptoms. Zinc sulfate application is the standard curative measure recommended in agricultural extension programs across India.