Chemical Management of Garden Sorrel (Rumex acetosa) in Perennial Alfalfa (Medicago sativa)

Alfalfa as a forage crop constitutes the largest area of planting in the world as Iran. Weed control is often accomplished by using herbicides in alfalfa fields. Six herbicides are recommended for using in alfalfa. Effective use of herbicides is related to several factors, such as time of application, dosage, environmental conditions, method of use, desired plant, frequency of use, etc. Unfortunately, over the past few years, there have been no considerable researches on additives and the context of their use has not been provided practically by farmers. Consequently, only three additives have been recorded by the Pesticides Supervision Board in Iran. In order to investigate the effect of different herbicides application on Garden Sorrel (Rumex acetosa) in alfalfa farms and its impact on alfalfa’s hay, an experiment through the completely randomized block design with four repetitions during cropping season 2012-2013 in the Amzajerd village, the city of Hamadan was performed. Ten treatments were considered which were included in two levels. Original treatments were in standard dose (Pursuit, Bazagran and Lentagran) and integrated treatments with 50% reduce doses.All of treatments includes: three levels (Standard Dose Herbicides), three levels (20% Reduce dose herbicides with cytogate application) and three levels (combination treatments by 50% reduce dose herbicides and cytogate application) as well as. After 50% of flowering of alfalfa in each cutting, selection of sample was performed by quadrate area in 1m2 and quality and quantity were measured for weed and alfalfa that include: Density and dry weight. All of treatments were effective on Garden Sorrel (Rumex acetosa). Integrated methods were very influencing on control of Garden Sorrel (Rumex acetosa). Treatments applied along with the cytogate surfactant were more efficient for weed control, as well as for an increase of the product yields, as imazethapyr herbicide along with cytogate surfactant managed to control weeds for a rate of 88.63% and increase the product yields to 89.74%.The Pursuit herbicide is a chemical treatment of the ALS family, which can be effective in broadleaf weed control. Cytogate can also increase the controlling power of this treatment, as seen in most of the harvests; this treatment could be preferred over other treatments as it appropriately controls weeds. Since the positive effect of Cytogate in increasing the efficiency of the mentioned herbicides was evaluated and effective results were obtained, it is recommended that this adjuvant should be employed in fields where the spectrum of the mentioned herbicides is used. Although the positive effect of applying Cytogate in improving weed control in fields has been proved, yet it is suggested that other adjuvants be evaluated together with other types of herbicides by researchers so that the synergistic and antagonistic effects of these adjuvants on these herbicides can be determined.

Keywords:

Alfalfa , Weeds , Herbicides , Dose application