SCREENING FAISALABAD FLORA FOR ALLELOPATHIC POTENTIAL

Indiscriminate pesticidal usage has fabricated harsh effects on environment, human and animal health. None chemical pest control is therefore gaining attraction now a days; allelopathy has emerged as natural technique of pest management in recent years in this regard. Various plants were sampled from different parts of Faisalabad and their extracts were prepared in Weed science and Allelopathy Laboratory, Department of Agronomy, University of Agriculture, Faisalabad, Pakistan. The extracts were then applied to the maize seeds to check their allelopathic activity. Total phenolic, EC and pH of the extracts were determined to find out the relation between allelopathic activity and their biochemical properties. Results showed that 62 plants had significant inhibitory effect (>20% inhibition) where as 35 plants had significant promotory effect (>20%). Plant water extracts of Heliotropium europoeum, Rumex dentatus, Tribulus terestris, Sesbania sesban and Trianthema portulacastrum showed highest inhibitory effect where as Gossypium arboreum, Cassia fistula, Conyza ambigua and Quercus Virginia had highest promotory effect. Positive correlation was found between inhibition percentage, and phenolic contents. From preliminary screening about 32 plants were selected and further checked against lettuce and these selected plant were used as natural bio-herbicide on three noxious weeds of wheat (Cronopus didymus, chenopodium murala and Avena futua). Resulted aqueous extracts should be used as potent plants on their allelopathic behavior for natural integrated crop management.