Allelopathic screening of Malaysian noxious weeds and several medicinal plants as potential alleloherbicides

Abstract

Aim: This research was conducted to assess the allelopathic potential of 100 plants species, including noxious weeds and medicinal plants of Malaysia as donor plant on the growth of Lactuca sativa (lettuce) as the recipient plant. This study was also carried out to justify common weeds found in Malaysia to act as a natural herbicide for weed management through allelopathy phenomenon. Methodology: Weed and medicinal plant species commonly found in Malaysia were identified according to their morphological characteristics. Sandwich method was carried out to determine the allelopathic potential of weed species through leaf litter leachate mechanism. On the other hand, dish pack method was conducted to discover the allelopathic potential of weed species through volatilization pathway. Results: 100 weed species and medicinal plants commonly found in Malaysia inhibited the radicle and hypocotyl growth of L. sativa by both sandwich method and dish pack method. Among 100 weed species, Passiflora foetida showed the maximum inhibitory effects on L. sativa growth in both sandwich and dish pack method. The highest amount of P. foetida leaf litter (50 mg), completely inhibited the growth of radicle and hypocotyl of L. sativa. Volatilization of weed and medicinal plants leaf litter inhibited the growth of L. sativa with increasing distances of lettuce seed with the weed and medicinal plants leaf litter. Interpretation: The findings of this study provides a base line for identifying plants with allelopathic properties for controlling weed propagation.