Effect of Clay, Soil Organic Matter, and Soil pH on Initial and Residual Weed Control with Flumioxazin

Abstract

Greenhouse studies were conducted to evaluate the effects of soil organic matter content and soil pH on initial and residual weed control with flumioxazin by planting selected weed species in various lab-made and field soils. Initial control was determined by planting weed seeds into various lab-made and field soils treated with flumioxazin (71 g ha−1). Seeds of Echinochloa crus-galli (barnyard grass), Setaria faberi (giant foxtail), Amaranthus retroflexus (redroot pigweed), and Abutilon theophrasti (velvetleaf) were incorporated into the top 1.3 cm of each soil at a density of 100 seeds per pot, respectively. Emerged plants were counted and removed in both treated and non-treated pots two weeks after planting and each following week for six weeks. Flumioxazin control was evaluated by calculating percent emergence of weeds in treated soils compared to the emergence of weeds in non-treated soils. Clay content was not found to affect initial flumioxazin control of any tested weed species. Control of A. theophrasti, E. crus-galli, and S. faberi was reduced as soil organic matter content increased. The control of A. retroflexus was not affected by organic matter. Soil pH below 6 reduced flumioxazin control of A. theophrasti, and S. faberi but did not affect the control of A. retroflexus and E. crus-galli. Flumioxazin residual control was determined by planting selected weed species in various lab-made and field soils 0, 2, 4, 6, and 8 weeks after treatment. Eight weeks after treatment, flumioxazin gave 0% control of A. theophrasti and S. faberi in all soils tested. Control of A. retroflexus and Chenopodium album (common lambsquarters) was 100% for the duration of the experiment, except when soil organic matter content was greater than 3% or the soil pH 7. Eight weeks after treatment, 0% control was only observed for common A. retroflexus and C. album in organic soil (soil organic matter > 80%) or when soil pH was above 7. Control of A. theophrasti and S. faberi decreased as soil organic matter content and soil pH increased. Similar results were observed when comparing lab-made soils to field soils; however, differences in control were observed between lab-made organic matter soils and field organic matter soils. Results indicate that flumioxazin can provide control ranging from 75–100% for two to six weeks on common weed species.

Sustainable Control of Galinsoga parviflora with Oxyfluorfen, Flumioxazin, and Linuron Application in Two Soils Cultivated with Garlic

“…Sorption-desorption studies showed that the sorption capacity of flumioxazin in soil correlates positively with increasing CEC and OM of the soil. The correlation coefficients between sorption K d values and CEC and OM content were 0.9909 and 0.8390, respectively [36]. These data are consistent with the present study, where the higher OM and CEC content of Ultisol compared to Oxisol resulted in higher doses to achieve C 80 and GR 80 .…”

“…The sorption of flumioxazin to soil particles is mainly attributed to the hydrophobic binding. OM and clays provide the necessary conditions for the sorption of flumioxazin due to the hydrophobicity of the particles [36]. However, the bioavailability of flumioxazin in soil solution also depends on the water content of the soil.…”

Preemergence herbicide premixes reduce the risk of soil residual weed control failure in corn

“…A generalized linear mixed model with a beta distribution and logit family ( glmmTMB package; Brooks et al 2017) was used to analyze both response variables. PRE herbicide efficacy is known to vary by year and location because of weather and soil conditions (Glaspie et al 2021; Landau et al 2021a) and soil seedbank weed community composition (Striegel et al 2021a). Therefore, data were analyzed separately by weed species and site-year.…”

Evaluation of imazapic and flumioxazin carryover risk for Carinata (Brassica carinata) establishment

“…Soil properties should also be considered when selecting the proper herbicide as part of a well-designed crop rotation. For example, flumioxazin persistence in soil is highly dependent on organic matter and water content, which are directly involved in the microbial-mediated degradation of this herbicide (Chen et al 2021;Glaspie et al 2021). In addition, soil texture plays a major role in herbicides' sorption on soil particles and their bioavailability.…”