Response of Lettuce (Lactuca sativa L.) to Foliar Spray Using Nano-Urea Combined with Mycorrhiza

Abstract

A factorial randomized complete block field experiment was carried out on lettuce (Lactuca sativa var. longifolia cv. Balady), grown on a heavy clay torrifluvent soil during two successive seasons (2016/2017 and 2017/2018) at the farm of the Faculty of Agriculture, Moshtohor, Benha University to study foliar application with nano-urea and biofertilization using Vesicular Arbusclar mycorrhiza (VAM). Factor 1 included 2 treatments: none (B 0) and VAM (B 1); Factor 2 included 5 treatments: no urea spray (spray with water) (N 0), spray with ordinary urea at 5000 mg N L-1 (N 1), spray with nano-urea at 2500 mg N L-1 (N 2), 3750 mg N L-1 (N 3) and 5000 mg N L-1 (N 4). Spray was in 3 times 30, 40 and 50 days after transplant at a rate of 1200 L ha-1 each time. All growth parameters of plant height, number of leaves plant-1 , fresh and plant dry weight increased by N or VAM singly or combined. Highest positive response occurred in plant height as well as weight and given by N 3 B 1. All nano-urea treatments surpassed the ordinary one, particularly the middle nano rate. The highest nano rate seemed excessive since N 3 did not continue to score further increase. Contents on N, P and K increased by nano-urea. NO 3-N increased progressively with increased application of urea, and the increase progressed with increased rate of nano-urea. The nano application proved practical and more efficient since a concentration of as low as 2500 mg N L-1 proved superior to that of 5000 and mg N L-1 ordinary urea N.