Effect of Micro Irrigation Systems on Yield and Phytophthora capsici Disease Control of Pepper

This study was conducted to determine the best micro irrigation system for pepper cultivation during two years. The goal of this study was water saving and reduction the disease progress (Phytophthora capsici) in the field condition. Experimental design was split plot based on randomized complete blocks design with four replications. Three different drip irrigation methods; drip irrigation with in-line emitter tubes، drip irrigation (tape)، and drip irrigation with porous pipes as main plot and three different amount of water (50، 75 & 100% water requirement) were as sub-plot. The result showed that the drip irrigation had the highest effect on disease control. The drip irrigation (tape) with 100% and 75% water requirement treatments had the lowest progress of Phytophthora capsici. In the first year the effect of irrigation method on yield and progress of Phytophthora capsici was significant. The effect of irrigation levels on the characteristics of plant except yield was no significant (α < 0. 01)، but the effect of irrigation methods on water use efficiency was significant (α < 0. 05). The drip irrigation (tape) with 100% and 75% water requirement treatment had the highest water use efficiency. In the second year the effect of irrigation levels and irrigation methods on yield was significant (α < 0. 05)، but the effects of combination of irrigation levels and methods on yield was not significant. The drip irrigation (tape) with 100% water requirement treatment had the highest yield. The result in two years showed that the pepper is a sensitive plant to water deficit. The drip irrigation (tape) and 100% water requirement treatment had the highest yield (7214 Kg) and water use efficiency (1. 311 Kg/m3). The result also showed that the porous pipes had no good efficiency. According to the results، the best option for pepper is drip irrigation (tape) with using 100% water requirement.