Biuret in urea applied as a foliar spray in citrus fruits should not be more than

Urea of foliar spray should not contain biuret more than 0.25% for citrus fruits. Fertilizer-grade urea contains the impurity Biuret which is toxic to the plant, especially when applied as a leaf dressing. Thus Biuret more than the advised percentage for specific plants can damage the root of the plant and also useful bacteria and chock the capillary of the root cell, Nitrogen carrying capacity will be reduced.