Laboratory experiments were conducted to determine the release of oxadiazon coated on control-release fertilizers. Five fertilizers and glass beads (nonabsorbent control) were coated with 14C-oxadiazon + formulated oxadiazon at a herbicide-to-fertilizer concentration of 0.3 mg ai/g. Coated fertilizers were subjected to 14 consecutive daily water leaching events. For the control-release fertilizers, Nutricote, Meister and Osmocote, 70%–80% of the coated oxadiazon was released in the first 3 leaching events; each leaching event after the 7th leaching event contained less than 1% of total applied oxadiazon. In contrast, 56% of the total applied oxadiazon was leached from Polyon 24N–1.7P–10K (24–4–12) in the first 3 leachings and similar percentages of oxadiazon were leached over each of the last 11 leaching events. Coating the five fertilizers with isoxaben produced similar results. A second experiment evaluated the effects of the addition of Prime Oil, Complex (sticker), Plex (sticker), and Intac (sticker) on release rates of oxadiazon-coated Osmocote 17N–3.1P–10K (17–7–12). Oxadiazon-coated Osmocote alone and oxadiazon-coated Polyon alone were also evaluated. Eighty-five percent of the total applied oxadiazon was leached from oxadiazon-coated Osmocote alone during the first leaching event and less than 1% was recovered with each consecutive leaching after the third leaching. Oxadiazon-coated Osmocote treated with Plex responded similarly to oxadiazon-coated Osmocote. Oxadiazon-coated Osmocote treated with Complex, Intac, or Prime Oil and oxadiazon-coated Polyon lost 21%, 20%, 16%, and 24%, respectively, of the applied herbicide after the first leaching event. Thereafter, nearly equal amounts of oxadiazon (5%) were leached from Complex, Prime Oil, Intac and Polyon alone from the 6th through the 11th leaching events.
Flumioxazin is a protoporphyrinogen oxidase (Protox) inhibitor with potential for postemergence (POST) control of annual bluegrass (Poa annua L.) and preemergence (PRE) control of smooth crabgrass [Digitaria ischaeum (Schreb.) Schreb. ex Muhl.] in bermudagrass [Cynodon dactylon (L.) Pers.]. However, flumioxazin efficacy is reduced under low temperatures, and control is often inconsistent on mature annual bluegrass. The objective of this research was to evaluate the use of adjuvants on flumioxazin efficacy for POST control of annual bluegrass and residual smooth crabgrass in bermudagrass. Tank‐mixing methylated seed oil, nonionic surfactant, or ammonium sulfate did not improve POST annual bluegrass control from flumioxazin at 0.42 kg active ingredient (a.i.) ha−1 alone. Granular urea antagonized flumioxazin efficacy and increased the time to achieve 50% annual bluegrass control (C50) by more than 4 weeks. Flumioxazin alone controlled annual bluegrass >80% at 9 weeks after treatment in both years. All treatments provided excellent (90 to 100%) control of smooth crabgrass at 4 months after treatment (MAT) and ≥89% control at 5 MAT. All flumioxazin treatments provided >70% control of smooth crabgrass and reduced grid count cover >65% from the untreated at 7 MAT. Although adjuvants did not enhance speed of annual bluegrass control from late‐winter applications, flumioxazin alone controlled annual bluegrass >80%, and provided >80% PRE control of smooth crabgrass.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
hi@scite.ai
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.