تاثیر بازدارندگان فتوسیستم 2 بر روند منحنی کاتسکی و پارامترهای فلورسنس کلروفیل در سلمه‌تره (Chenopodium album L.) و خرفه (Portulaca oleracea L.)

Chlorophyll fluorescence technique is non-invasive and indirectly process which useful for assessment of rapid photosynthetic apparatus activity changes. In order to determine how exposure affects the fluorescence induction curve (Kautsky curve) and its parameters, two dose-response experiments carried out for chlorophyll fluorescence measuring. 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 and chloridazon at 0, 81.25, 162.5, 325, 650, 1300, 1950 and 2600 gr a.i. ha-1 on common lambsquarters (Chenopodium album L.) and common purslane (Portulaca oleracea L.) at the research glasshouse of Agricultural Faculty of Ferdowsi University of Mashhad, Iran. The measured parameters showed also different sensitivity to the herbicides application, so that, four hours after desmediphamand+phenmedipham+ethofumesate application on weeds mentioned, maximum quantum efficiency of PSII (Fv/Fm), did not show any change whereas the relative change in fluorescence (Fvj) J and the area between the curve and Kautsky (Area) Fm strongly reduced during this period, but chloridazon usage was not changes on Kautsky curve and their parameters during this period due to lower solubility, and sediment deposition in the sprayer tank mix. Is this translation better than the oYes, submit translaThank you for your submission.Common purslane was more affected by desmediphamand+phenmedipham+ ethofumesate and chloridazon application because of sponge leaves and stems while had lesser sensitivity to both of herbicides application due to powdery and white cover over leaves and stems.