Using Reduced Rates of Trifluralin and Hand Weeding in Sustainable Weed Management of Fennel (Foeniculum Vulgare Mill.)

Using reduced rates of herbicide as integrated with hand weeding is one of the important strategies for sustainable weed management. In order to introduce a practical method for sustainable weed management of fennel (Foeniculum vulgare Mill.)، an experiment was carried out in 2011. The experiment was conducted as factorial based on randomized complete block design with three replications. The herbicide was applied preplant-incorporated at 0، 480، 960، 1440، and 1920 g a. i. ha-1. The second factor was supplementary weed control at two levels including one-hand weeding and no-hand weeding. A plot with whole season hand weeding was also included as check. Results showed that without weed control، fennel yield was decreased up to 88. 2%، indicating the susceptibility of this plant to weed competition. Weed biomass and fennel yield loss were affected significantly by herbicide and hand weeding as well. Grass weeds were more susceptible to given rate of the herbicide compared with broadleaf weeds. Combination of herbicide with one hand weeding generally improved both grass and broadleaf weeds control. In spite of that، application of recommended rate of trifluralin (1440 g a. i. ha-1) with one hand weeding did not suppress yield loss، which in such treatment 13% yield loss was observed. Also، more effective herbicides and other non-chemical weed management approaches in integration with herbicides should be used in this medicinal plant.