Investigation of Effects of Control Method on Immersed Aquatic Weeds

Chara Vulgaris and Najas felexilis both are immersed aquatic weeds; which found in stagnant waters rich in nutrient. Unlimited growth of these plants resulted in declining water use efficiency and could bear ecological and economic damages to the environment. In most of the fresh water systems such as lagoons, rivers and lakes, successful control of diverse weed species were demonstrated using mechanical methods. The aim of this study was evaluating immersed aquatic weeds response, C.vulgaris, and N.felexilis to cutting in three levels (no cutting, one-time cutting and twice) in Azadegan Park’s lake of Tehran. the experiment performed as a factorial design in the base of completely randomized design with three replications. Measured characteristics included the height and dry matter evaluation in experimental plants.Results showed that one time cutting in comparison to control treatment decreased C.vulgaris and N.felexilis as 43.75 and 13.8 %. Then twice cutting decreased plant growth and regeneration significantly rather than one-time cutting (P≤0.05). Results showed that the lowest dry weight reduction and height in two-time hew were observed in Chara.Vulgaris. So cutting off and its periodic repetition resulted in proper control effect on experimental plants due to inducing stress and reducing higher carbohydrate storage.  

Keywords:

Immersed Weeds , Azadegan Lake , Cutting off , Height and Dry Weight