Effect of Safener, Activated-charcoal Coated Seed,and Charcoal Banding on Establishment ofSwitchgrass Receiving Pre-emergent Herbicides

摘要

Switchgrass (Panicum virgatum L.) is typically slow and difficult to establish due tocompetition from weeds. Two experiments were conducted evaluatingeffectiveness of seed safeners and activated charcoal on prevention of herbicideinjury of ‘Alamo’ switchgrass. In experiment I, a completely randomizedgreenhouse experiment with three replications evaluated a factorial arrangementof five (0, 0.64, 0.96, 1.28, and 1.92 fluid oz/100 lb seed) fluxofenin (Concep III)rates and four herbicide treatments: metolachlor, metolachlor plus atrazine,pendamethalin, and an untreated control. In experiment II, a randomizedcomplete block field experiment with a split plot arrangement of treatments andfour replications evaluated charcoal seed treatments. Main plot treatmentsconsisted of uncoated seed plus 250 lb/acre charcoal slurry in a 2-inch band overthe seed row, charcoal coated seed at either 4:1, 6:1, or 8:1 charcoal weight:seedweight ratios, and non-treated seed. Sub-plot treatments consisted of fiveherbicide treatments: atrazine, metolachlor, metolachlor plus atrazine, imazapic,and an untreated control. In experiment I, fluxofenin did not safen switchgrassseeds from these herbicides. In experiment II, charcoal treatments safenedswitchgrass seed in 2 of 4 years, when precipitation was above normal, but failedto safen switchgrass seed when rainfall was below average. In addition,switchgrass ground cover at end of season was generally below the minimum 40%threshold; therefore improved establishment techniques are still needed forswitchgrass.