ALLELOPATHIC EFFECT OF SOME NATURAL PLANTS ON SEED GERMINATION AND GROWTH OF Phalaris canariensis L. AND Lactuca sativa L.

Unlike chemical herbicides, the use of natural products can reduce negative impacts on the environment. In this sense, Allelopathy is considered as a promising method for biological control. However, the effects of allelopathic substances remain low tested in laboratory and field conditions. The objective of this study was to test the effect of leaves extracts from eight plant species on the germination and growth of canary grass (Phalaris canariensis L.) and lettuce (Lactuca sativa L.). Foliar extracts of the tested plants have a more significant allelopathic effect on germination and growth of canary grass than of the lettuce. In general, the effects were observed starting from the lowest concentration (0.5%) and the rate of reduction increased with the increase in the concentration of extracts. This inhibitory effect on canary grass showed reductions rates ranging from 14 to 100% for germination and between 5 and 100% for the growth both of coleoptile and radicle. On lettuce, the extracts tested of different plants showed no significant effect on both germination and growth. However, Pistacia Lentiscus extract had a significant stimulating effect on germination at 2 and 4% concentration on lettuce in the order of 7.18%. Thus, the tested aqueous extracts showed good to very good herbicidal efficacy on Phalaris canariensis and very good to excellent selectivity towards Lactuca sativa.