Herbicides and interim summer crop treatments were studied in 1984 to 1987 to replace fungal endophyte-infected with endophyte-free tall fescue or red clover to improve forage quality. Foliar glyphosate or paraquat were applied in spring across interim crops with PRE herbicides. The interim crops, grain sorghum with atrazine, sorghum-sudangrass hybrid with metribuzin, or soybean with imazaquin, were each applied as confounded treatments across glyphosate or paraquat. Within an interim crop system, a follow-up glyphosate treatment was serially applied the next fall or spring. Then either red clover or endophyte-free tall fescue was spring drilled within the fall or spring glyphosate follow-up treatments. Glyphosate controlled old tall fescue better than paraquat, and improved the stand of the endophyte-free tall fescue. Control of tall fescue was 97% from 1.7 kg ai/ha glyphosate. Glyphosate reduced the endophyte from a 77% original infection level to 20% over all interim crops after drilling the endophyte-free tall fescue. Among interim crops, grain sorghum or the sorghum-sudangrass hybrid was more competitive than soybean with the uncontrolled tall fescue. Replacement with endophyte-free tall fescue was best in grain sorghum or sorghum-sudangrass hybrid stubble the next spring. Grain sorghum or sorghum-sudangrass hybrid following foliar glyphosate or paraquat treatment of endophyte-infected tall fescue reduced endophyte infection level in tall fescue to 28%. A follow-up fall treatment with glyphosate controlled tall fescue better than the spring retreatment and red clover and endophyte-free tall fescue were established better from fall retreated glyphosate. Red clover was easily established by drilling into the sod after treating endophyte-infected tall fescue with either glyphosate or paraquat.
Planting tall fescue (Festuca arundinacea Schreb.) seed free of the endophyte Acremonium coenophialum Morgan‐Jones & Gains allows establishment of swards free of the fungus. Eradication of the fungal endophyte from infected tall fescoe seeds containing 130 g kg−1 moisture using ionizing radiation was investigated. Three sources of radiation were used: gamma rays (60Co source), neutron particles (252Cf source), and a thermal neutron beam. The percent germination of tall fescue seeds among gamma doses did not differ significantly (P < 0.05) from the control treatment and did not show a significant negative response (R2 = 0.41) to increasing levels of gamma radiation. At 250 Gy of gamma radiation, percent germination after 14 d was still =90%. Percent seed germination of tall fescue and high levels of radiation were negatively correlated for both sources of neutrons. Gamma radiation was shown to reduce (P < 0.01) the percent of the viable endophyte to =10% of control. The 2s2Cf and thermal neutrons reduced the percent of tall fescue infected by the endophyte to =30% without deleterious effects on seed germination.
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.