Document Type : Research Paper

Authors

1 Master of Fisheries / Research Sciences of Tehran

2 Associate Professor / Department of Agronomy and Plant Breeding Shahed University of Tehran

Abstract

 



Chara (Chara vulgaris) and Najas (Najas felexilis) are two submersed weeds which are found in rich waters. The excessive growth of these plants cause the reduction in utilization of water resources and making some ecological and economical damages in these areas. In most fresh water systems، such as wetlands، streams and lakes، the efficacy of mechanical methods is well documented for major weed species. The aim of this study was to determine the response of C. vulgaris and N. felexilis to cutting in three levels (once، twice and without cutting) in Azadegan lake park of Tehran. The test was examined in factorial design with three replications. The tested parameters included plant length and dry weight. 
The results of this experiment showed that once cutting in comparison with control treatment، made 43/75 and 13/8 percent reduction in length of C. vulgaris and N. felexilis، respectively. Also، twice cutting compared with only once، caused considerable (P≤0.05) reduction in growth of test plants. Thus، cutting and its replication، because of creating more stress and reduction in carbohydrate stock، brought about a better control effect on test plants. 

Keywords

سواری­پور، غ. 1386. شناسایی و مدیریت علف­های هرز آبزی دریاچه بوستان آزادگان تهران. پایان نامه دوره ارشد مهندسی منابع طبیعی شیلات. دانشگاه آزاد علوم و تحقیقات تهران.
 
Adamec, L. and Husak, S. , (2002) Control of Eurasian Watermilfoil in NNR Brehynsky Fishpond Near Doksay, Czech Republic. J. Aquatic Plant Management. 40: 45-46.
Barko, J. W, Adams, M. S. and Clescer, N. L. , (1986) Environ-mental Factors and Their Consideration in The Management of Submersed Aquatic Vegetation: A review. J. Aquatic Plant Manag-ement. 24: 1-8.
Best, E. P. H, (1993) The Impact of Mechanical Harvesting Regimes on the Species Composition of Dutch Ditch Vegetation: A Quantitative Approach. J. Aquatic Plant Manage. 31: 148-154.
 
 
Chambers, P. A, Brako, J. W. and Smith, C. S. , (1993) Evaluation of Invasion and Declines of Submersed Aquatic Macrophytes. J. Aquatic Plant Manage-ment. 31: 218-220.
Cromwell, G. , (2008) AnnualReportSouth IslandLakes Aquatic Plant Weed Control.Landward Manage-ment Ltd, LINZ Bio Security. 13: 26-32.
Filizadeh, Y and Murphy, K. , (2002) Response of Sago Pondweed to Combinations of Low Doses of Diquat, Cutting, and Shade. J. Aquatic Plant Management. 40: 72-76.
Grime, J. P. , (1979) plant strategies and vegetation processes. Wiley, Chichester. 222 pp.
Gunkel, R. C. and Barko, W. , (1998) An Overview of The Aquatic Plant Control Research Program. J. Aquatic Plant Management. 36: 23-24.
Hawes, L. , Riis, T. , Sutherland, D. and Flanagan, M. , (2003) Physical Constraints to Aquatic Plant Growth in New Zealand Lakes. J. Aquatic Plant Management. 41: 44-52.
NI, L. , (2001) Effects of Water Column Nutrient Enrichment on The Growth of (Potamogeton maack-ianus). J. Aquatic Plant Management. 39: 83-87.
Perkins, M. A, and Sytsma, M. D. , (1987) Harvesting and Carbohydrate Accumulation in Eurasian Water-milfoil. J. Aquatic Plant Manage-ment. 25: 57-62.
Robertts, D. E. , Sainty, G. R. , Cummins, S. P. , Hunter, G. J. , and Anderson, L. W. J. , (2001) Managing Aquatic Plants in the SydneyInternationalReggataCenter, Australia. J. Aquatic Plant