Urea absorption by canon leaves as affected by solution pH.

Abstract

Cotton planta are sensitive to time and rate of N fertilization. Foliar spraying with urea may be an effective way for top-dressing N ia cotton (Gossypium hirsujum L.) crops, although some loss can be observed due to volatilization. Urea ("N) was applied to cotton leaves ia greenhouse condidons, and the N uptake was monitored up to 24 hours after application. Urea solutions pll were adjusted to 3.0, 4.0, 6.0 and 7.0. Alter 24 hours N volatilization was calcu!ated. Urea solutions with p11 3.0 and 4.0 showed a higher N uptake rate than solutions with pU 6.0 and 7.0. After 24 hours more than 90% of the N applied was recovered ia cotton planta. There was not a definitive evidence of N volatilization due to urease activity ia cotton leaves.