Effect of poultry manure and spraying with urea on growth and yield parameters of local lettuce

This study aims to study the effect of the interaction between poultry manure levels and foliar urea concentrations in improving the growth and productivity of the lettuce plant. A field experiment was undertaken during the 2024–2025 winter growing season to investigate the impact of varying poultry manure levels and urea foliar spray on local lettuce growth and productivity. The experiment was conducted in the College of Agriculture, University of Anbar, Iraq, at roughly 33.35° N latitude and 43.79° E longitude. Three poultry manure levels (0, 15 and 30 t ha-1) and 3 foliar urea concentrations (0, 0.5 and 1 %) were tested. The experiment employed 3 replications as a randomized complete block design (RBD). Application of 30 t ha-1 poultry manure significantly increased plant height, total number of leaves, leaf area, plant weight and total yield, with the highest yield of 58.32 t ha-1. As for the effect of spraying with urea, the U2 treatment showed the best values for the studied traits including (plant height, total number of leaves, leaf thickness, leaves area, head diameter, total plant weight and total yield) which reached (42.03 cm, 64.17 leaf plant-1, 0.32 mm, 35.94 dm² plant-1, 20.54 cm, 1.68 kg and 55.69 t ha-1), respectively. On the other hand, the overlap of the 2 study factors revealed a significant effect on all examined parameters excluding leaf thickness and the best values for all traits appeared when W2U2 was treated, while the treatment of no addition of poultry manure and spraying with urea W0U0 showed the lowest values for all parameters. It is concluded from our study that the use of poultry manure and spraying with urea contributes significantly to boosting the growth traits of Local lettuce, which is demonstrated positively in increasing the yield, so we recommend through the results of the study organic fertilisation with poultry manure and spraying with urea, as well as the interaction of the 2 study factors in order to give the best growth and yield to lettuce plants.