بررسی کنترل برخی از پهن‌برگهای مهم اراضی چغندرقند (Beta vulgaris) با استفاده از آزمون دز- پاسخ طی آزمایشات گلخانه‌ای

To evalution of redroot pigweed (Amaranthus retroflexus), common lambsquarters (Chenopodium album L.), common purslane (Portulaca oleracea L.) and black nightshade (Solanum nigrum) control on reduce dosage, four dose-response experiments were carried out in completely random design with nine treatments and three replication at Ferdowsi University of Mashhad in the research greenhouse. The treatments involved desmediphamand+phenmedipham+ ethofumesate at 0, 51.38, 102.75, 205.5, 308.25, 411, 616.5 and 822 gr a.i. ha-1, chloridazon at 0, 81.25, 162.5, 325, 650, 1300, 1950 and 2600 gr a.i. ha-1, clopyralid at 0, 15, 30, 60, 90, 120, 180 and 240 mg a.i. ha-1. The results showed that redroot pigweed, common lambsquarters, common purslane and black nightshade dry weight were decreased on reduce dosage by all three desmediphamand+phenmedipham+ ethofumesate, chloridazon and clopyralid herbicides application. Common purslane due to the high sensitivity leaves and stems more affected by all three herbicides application, whereas common lambsquarters had more resistance to desmediphamand+phenmedipham+ ethofumesate, chloridazon and clopyralid usage because of existence powdery covering on abaxial side of the leaves, resulted to decline the penetration of herbicide in to plant tissue. Among herbicides treatment, desmediphamand+phenmedipham+ ethofumesate had more effect on whole weeds control compared chloridazon and clopyralid. Therefore, it has been recommended to use desmediphamand+phenmedipham+ethofumesate rather than chloridazon and clopyralid for these adequate weed control in sugar beet.