Allelopathic Effects of Bell Pepper Organ's Extract on Growth Characteristics of Cucumber (Cucumis sativus L.), Eggplant (Solanum melongena L.), Bell Pepper (Capsicum annum L.), and

Some crops have allelopathic effects that could be interested to study the effects on other crops, particularly in rotation and intercropping system. In this study, the allelopathic potential of bell pepper organs extract on seedling growth of cucumber, eggplant, bell pepper, and tomato was separately evaluated using a complete randomized design, in a hydroponic system under greenhouse conditions. The first variable was plant type (cucumber, eggplant, pepper, and tomato) and the second one was pepper organ type that extracted (leaf, root, and stem). Alcoholic extracts (5% w/v) of leaf, root, and stem of pepper were prepared. Then these extracts effects were investigated on all plant growth indices including number of leaves and flowers, root and shoot length, root and shoot fresh weight, and root and shoot dry weight. The results showed that all pepper organs extracts have similar effect on growth characteristics reduction of the other plants. Also, leaf extract had the most effect on reduction of growth of all the plants. It seems that the leaf had the most allelopathic effect as compared with the others. So, this effect may be related to production of allelochemicals in pepper leaves.