Submitted to: American Society of Agronomy
Publication Type: Abstract Only
Publication Acceptance Date: 6/19/2000
Publication Date: N/A
Technical Abstract: Identifying more cost effective and reduced chemical techniques for cover crop management can increase their use. This study was conducted to determine the effectiveness of using a mechanical roller-crimper as an a alternative kill method for cover crops. Three cover crops, rye (Secale cereale L.),wheat(Triticum aestivum L.), and black oat (Avena strigosa Schreb.) were evaluated for ease of kill and optimum time of kill using a roller-crimper, two herbicides (paraquat and glyphosate), and two reduced chemical rate combinations of the two methods. The study took place at two locations in east-central Alabama, using a split-split plot design with four replications. Three Feekes' scale growth stages (GS) were used to determine optimum time of kill; 8.0 (flag leaf), 10.51 (anthesis), and 11.2 (soft dough). Percent kill measurements were taken 14 d after treatment. Black oat reached maximum biomass at anthesis (8.58 Mg/ha) while rye and wheat increased biomass significantly through soft dough (9.50 Mg/ha and 10.46 Mg/ha, respectively). There was a significant interaction between GS and kill method; by soft dough, kill methods were equally effective due to accelerating plant senescence (95% mean kill across methods). The label rate of glyphosate and « label rate+roller combination produced the best kill mean, 91% and 89%, respectively, at all GS levels across all cover crops. However, at anthesis, the label rate of paraquat and « label rate+roller combination were as effective (mean 89% kill) as glyphosate. This study shows that it is possible to reduce or eliminate the use of herbicides and implement effective alternative kill methods for cover crops.