بررسي اثر خاك ورزي و زمان كاربرد علف كش در مراحل مختلف فنولوژيكي بر كنترل علف هرز شيرين بيان (Glycyrrhiza glabra l.)

Effect of Tillage and Herbicide Application at Different Phenological Stages in Controling Glycyrrhiza glabra L.

Field experiments were conducted at Mahidasht Research Station in Kermanshah province during 2003-2004 to evaluate the efficacy of tillage, herbicide treatment and application timing in controlling Glycyrrhiza glabra L. Treatments were arranged as a spilt-spilt plot based on randomized complete block design with four replications. Main plots were constituted of tillage operations (moldboard plowed, no plowing) during 4-6 leaf stage of G. glabra, subplots were herbicide application timing (4-6 leaf stage and flower bud stage) while subsubplots different herbicide treatments including 2,4-D; clopyralid; triclopyr; a mixture of 2,4-D and clopyralid, mixture of 2,4-D and triclopyrʹ a mixture of clopyralid and triclopyr, and finally an untreated control. The important trait, G. glabra regrowth was not affected by herbicide application timing. The interaction of herbicide application timing and plowing on weed regrowth and dry-matter content showed that the highest control of G. glabra was obtained where G. glabra plants were plowed followed by being sprayed at flower bud stage. Interaction of herbicide treatment and plowing demonstrated that triclopyr had the highest effectiviness in controlling G. glabra where applied to unplowed land. Herbicide treatments were most effective when G. glabra plants sprayed at flower bud stage. Triclopyr was the most suitable treatment (85% control) when sprayed at flower bud stage, and accompanied by plowing.