In order to study of the efficacy of herbicides in weed control of new seeded alfalfa, an experiment was conducted in Hamedan and Yazd cities, Iran during 2009-2010. The treatments were Bentazone (Bazagran) (SL 48%) two, three and four L.ha-1, 2,4-DB (Butress) (EC 42.3%) 2.5, 2.8, 3.1 and 3.5 L.ha-1, Imazethapyr (Pursuit) (SL 10%) 0.4, 0.7 and one L/ha and without herbicide control treatment. The herbicides effect on alfalfa biomass and the biomass and density of weeds was studied during three cuttings. In Yazd, 2,4-DB 3.5 L.ha-1 was the best treartment for controlling weeds and increasing alfalfa biomass. 2,4-DB 3.5 and 2.8 L.ha-1 controled the density and biomass of Malva and Lactuca to 100 and 88 percent, respectively. In Hamedan, herbicides treatments had no phytotoxocity on alfalfa. Only Bentazone caused chlorosis in alfalfa that recovered that after one to two weeks. 2,4-DB not only was suitable in control ling broad leaves weeds, but also was successful in field bindweed control. Overall. 2,4-DB seems to be an efficient herbicide


1 . پیتر دی والتون. ترجمه محسن مدیر شانه‌چی (1369) تولید و مدیریت گیاهان علوفه‌ای. ناشر معاونت فرهنگی آستان قدس رضوی، 290 ص.
2 . زند ا.، باغستانی م. ع.، نظام‌آبادی ن. و شیمی پ (1386) راهنمای علف‌کش‌های ثبت‌شده در ایران. انتشارات جهاد دانشگاهی مشهد، 120 ص.
3 . فقیه ا.، نریمانی و. و برازی د (1377) بررسی و آزمایش اثر چند علف‌کش بر روی علف‌های هرز و یونجه آذربایجان شرقی (گزارش پژوهشی). بخش تحقیقات آفات و بیماری‌های گیاهی، مرکز تحقیقات کشاورزی آذربایجان شرقی.
4 . کریمی‌ ه (1369) یونجه. مرکز نشر دانشگاهی، 250 ص.
5 . Anomymous (2001) Crop Production. National Agricultural Statistics Service, United States Department of Agriculture.
6 . Badly KH (1997) Invistigation of weed control alfalfa on herbicides of post-emergence, Final Report. Iranian Research Institute of Plant Protection.
7 . Cords HP (1973) Weeds and alfalfa hay quality. Weed Science 21: 400-401.
8 . Curran WS, Hall M and Werner EL (1999) Effect of varying Imazethapyr application rate and timing on yield of seedling grass-alfalfa mixtures. Production Agriculture 12: 244-248.
9 . Dimitrova TS (1998) Study of the herbicide Pivot 100 EK for Cuscuta spp. control in an alfalfa stand establishment. Rasteniev"dni-Nauki 35: 651-655.
10 . Kiely T, Donaldson D and Grube A (2004) Pesticides Industry Sales and Usage: 2000 and 2001 Market Estimates. US EPA Pesticide Industry Sales and Usage: 2000 and 2001 Pesticide Market Estimates.
11 . Lubbers MD, Stahlman PW and Al-Khatib K (2007) Fluroxypyr efficacy is affected by relative humidity and soil moisture. Weed Science 55: 260-263.
12 . McCaslin M and Fitzpatrick S (2000) Roundup ready alfalfa. Proceedings of the 37th North American Alfalfa Improvement Conference. Pp. 396-400.
13 . McWilliam JR (1968) Lucerne, the plant. Australian Institute of Agricultural Science. 34: 191-193.
 14 . Nakamura K, Satake Y and Bando T (1998) Weed control in establishment of alfalfa sward. Bulletin-of-Hokkaido-Prefectural-Agricultural-Experiment-stations 75: 47-51.
15 . Sprague CL, Kells JJ and Schirmacher K (2005) Weed control guide for field crops. Cooperative Extension Service.
16 . Summers CG (1998) Integrated pest management in forage alfalfa. Integrated Pest Managemnet. Review.
3: 127-154.
17 . Waters B, Lee G and Christianson K (1998) Weed control in establishing stands of alfalfa. Proceedings of the Annual Meeting of the Western Society of Weed Science, Waikoloa, Hawaii, 10-12 March. 51: 90-94.
18 . Whitesides RE, Dewey SA, Enlone SF, Menalled FD, Miller SD and Johnson L (2004) Weed control in alfalfa in: Weed Management Handbook. 125 p.
19 . Wilson RG (1994) Effect of imazethapyr on legumes and the effect of legumes on weeds. Weed Technology. 8: 536-540.
20 . Zamora D, Alby T and Lym R (1991) Weed control in seedling alfalfa with imazethapyr. Proceedings of the Western Society of Weed Science, Seattle, Washington, USA, 12-14 March. 44: 97-98.
21 . Zimdahl RL (2007) Fundamentals of Weed Science. Elsevier Inc., USA. 250 p.