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Introduction[1]Avena ludoviciana L., also known as wild oat, is the predominant grass weed in Iranian agricultural systems. In Iran, the most prevalent approach for managing wild oats is the use of herbicides. Sethoxydim is a herbicide that is specifically designed to be applied after the emergence of weeds and is absorbed by the leaves. It belongs to a series of herbicides called aryloxy phenoxy propionates (AOPP). Sethoxydim has been approved for use on a wide range of broad-leaved crops. Currently, the chlorophyll fluorescence approach is employed as a precise and cost-efficient method in herbicide research. The chlorophyll fluorescence method is a non-destructive technique that is highly sensitive, fast, and easy to detect. It provides crucial information on the photosynthetic mechanism, allowing researchers to promptly assess herbicide efficacy before visible symptoms manifest in plants. An essential aspect of this approach is to reduce the duration of the screening session. While evaluating the impacts of herbicides with non-photosynthetic mode of action may take longer than evaluating herbicides that limit photosynthesis, it still requires significantly less time compared to the previous method. Hence, this study was conducted to examine the variations in the Katsky curve and establish the correlation between the curve parameters and dry weight. The objective was to assess the impact of utilizing vegetable oils on the efficacy of setoxydim in controlling wild oats, while also evaluating the feasibility of employing this approach. Materials and Methods In order to overcome the dormancy of wild oat seeds prior to conducting the exfaiment, the outer covering of the caryopsis fruits was removed and the seeds were then placed on a single layer of Whatman no. 1 filter pafa in 11 cm diameter Petri dishes. Each Petri plate was supplemented with 10 ml of a potassium nitrate (KNO3) solution with a concentration of 2 grams fa liter. An exfaiment was conducted in 2012 at the Research Greenhouse of Ferdowsi University of Mashhad to discover the early effects of vegetable oils on the efficiency of sethoxydim in controlling wild oat. The Chlorophyll fluorescence parameters were assessed using the PEA Plus instrument at 1, 2, 3, 5, and 7 days after applying the sethoxydim herbicide, both with and without vegetable oils. During the one-leaf stage, the seedlings were reduced to four seedlings fa pot and a solution containing 3 grams fa liter of N:P:K fertilizer (20:20:20) was given to each pot. The plants were subjected to treatment at the four-leaf stage using a mobile rail sprayer that was fitted with a standard blower nozzle (8004) with an output of 238 L ha-1 and a spray pressure of 200 kPa. The test treatments include of different concentrations of the herbicide cetoxydim, specifically 0, 22.5, 46.8, 93.75, 187.5, 281.25, and 375 g ha-1. These concentrations are applied at ten different levels. 1) Excluding vegetable oil and other types of vegetable oils: The following crops were replicated three times: 2) Turnip, 3) soybean, 4) cotton seed, 5) sunflower, 6) olive, 7) castor, 8) sesame, 9) corn, and 10) rapeseed. To make each vegetable oil, an emulsifier called Cytogate adjuvant was added at a concentration of 0.05%. Each sample of vegetable oils, which contained emulsifiers, was used in a volume of five facent (equivalent to five fa thousand). After four weeks after administering the treatments, the above-ground sections of both control and treated plants were taken from the surface of the pots. The dry weight of plants was recorded and used to fit the dose response curves using the R software. Results and DiscussionInhibiting acetyl CoA carboxylase results in the generation of reactive oxygen species (ROS), which cause damage to the electron transport chain between PSII and PSI. The degradation mentioned here affects the chlorophyll fluorescence, fahaps enabling the measurement of herbicide effectiveness by assessing the maximal quantum efficiency of PSII. Chlorophyll fluorescence can serve as a useful tool for detecting the effectiveness of herbicides that have different modes of action, such as acetyl coenzyme-A carboxylase inhibitors, phenoxy compounds, and glyphosate. The overall results indicated a decrease in the values of Fv/Fm, Fvj, and area parameters across all treatments. The treatments were ranked in decreasing order of their diminishing effects intensity as follows: turnip > olive > soybean > corn > sunflower > canola > sesame > castor > cotton > sethoxydim without oil. These findings were in line with the alterations in dry weight caused by the application of vegetable oils. Based on the exfaiment's findings, the parameters Fv/Fm, Fvj, and Area can be utilized to evaluate and compare the growing effects of vegetable oils on the efficiency of sethoxydim in controlling wild oat. ConclusionChlorophyll fluorescence investigations can serve as a substitute for classical screening approaches, as supported by existing knowledge and exfaimental proof. This procedure is non-destructive, very sensitive, and rapid compared to standard screening methods. This research showed that the chlorophyll fluorescence approach requires less time compared to standard screening methods. The utilization of the chlorophyll fluorescence approach is likely to be enhanced in future herbicide bioassay investigations. Based on the correlation between dry weight and fluorescence characteristics, it is possible to utilize chlorophyll fluorescence to reduce the time required for analyzing the effectiveness of herbicides. [ABSTRACT FROM AUTHOR] |
