Germination and Seedling Growth of Convolvulus arvensis L. and Cyperus rotundus L. under the Allelopathic Influence of Eucalyptus camaldulensis (L.) Leaves

The utilization of allelopathic properties of plants is thought to be an effective and environment-friendly approach for weed management. A pot experiment to evaluate the allelopathic potential ofleaves of Eucalyptus camaldulensis (L.) against Convolvulus arvensis (L.) and Cyperus rotundus (L.) was undertaken during summer 2011. The study was conducted at Department of Agronomy, Sindh Agriculture University, Tandojam, Pakistan. The experiment was laid out in three replicated completely randomized design. The treatments consisted of control (untreated), eucalyptus water extract at 10, 20 and 30 ml kg^-1 soil, eucalyptus powder at 10, 20 and 30 g kg^-1 soil, eucalyptus powder at 10 g kg^-1 soil+water extract at 10 ml kg^-1 soil, eucalyptus powder at 20 g kg^-1 soil+water extract at 20 ml kg^-1 soil and eucalyptus powder at 30 g kg^-1 soil+water extract at 30 ml kg^-1 soil. Data showed that all the treatments of eucalyptus leaves water extract and powder caused substantial (P ≤ 0.05) decrease in germination and seedling growth of C. arvensis and C. rotundus as compared to control. Integrated application of eucalyptus powder at 30 g kg^-1 soil+eucalyptus water extract at 30 ml kg^-1 of soil and eucalyptus powder at 20 g kg^-1 soil+eucalyptus water extract at 20 ml kg^-1 soil showed highest inhibitory effect. In both aforesaid treatments, lowest and statistically similar values of germination, root/ shoot length and fresh/ dry weight seedling^-1 were recorded for both C. arvensis and C. rotundus, respectively. The water extract of E. camaldulensis showed superiority in allelopathic effects over its powder. Inhibitory effect of water extract or powder increased at higher rate (30 ml or 30 g kg^-1 soil). Hence, results conferred that eucalyptus leaves possess allelopathic potential which could be utilized for suppression of weeds under field conditions.