Relationship of the NDVI index and the leaf greenness index SPAD to pinoxaden phytotoxicity in populations of Avena fatua of wheat and alfalfa crops from the Mexicali Valley in the laboratory

The visual method is used to evaluate the effectiveness of ACCase inhibitor herbicides on Avena fatua . Digital technologies can also be used to evaluate the efficacy of herbicides and detect damage to the photosynthetic apparatus. Given limited laboratory research on these methods, this study investigated the correlation between the Normalized Difference Vegetation Index (NDVI) and chlorophyll content in relation to pinoxaden phytotoxicity in two A. fatua populations. A completely randomized 2 × 4 factorial design included two populations and four pinoxaden concentrations. Measurements included percentage of control (%C), weed control index (WCI), dry matter (DM) production, NDVI vegetation indices, and SPAD units. A repeated-measures analysis with a factorial time arrangement was conducted, and least-squares means were compared using Tukey’s test. The percentage of control and vegetation indices were correlated using Pearson’s correlation. The relationship between the percentage of control and vegetation indices was determined using Pearson’s correlation. In contrast to the wheat population, the alfalfa population showed increases in %C and weed control index. In contrast, the alfalfa population exhibited lower dry matter, NDVI, and SPAD values, suggesting that pinoxaden is more phytotoxic to alfalfa. The NDVI, SPAD, and control percentages were negatively correlated in both A. fatua populations, suggesting that the vegetation indices decline as the control percentage increases. It is possible to estimate the toxicity of the herbicide pinoxaden in laboratory settings using instruments that quantify chlorophyll content and NDVI.