Efficacy of Some Plant Extracts against Root Rot Disease of Green Oak Lettuce (Lactuca sativa var. Crispa) Caused by Pythium sp. Grown in a Hydroponic System

An antifungal activity of the twelve plant extracts were tested against Pythium sp., causal agents root rot diseases grown in hydroponic systems. The crude Acorus calamus and Syzygium aromaticum completely inhibited mycelial growth sp. vitro condition at 5,000 ppm, whilst Curcuma zedoaria other had show lesser inhibitory activity. Out these selecting A. calamus, S. C. for further vivo test nursery raising seedling plastic tray system by inoculating developed on agar medium, rhizome extract exhibited highest effect % tip colonized 5.85 to 48 followed floral bud 9.97 60 28.32 90 2000 ppm seven twenty one days after inoculation respectively. concentrations application methods should be investigated control disease lettucein system.