Assessing the Efficacy of Living and Dead Cover Crop Mixtures for Weed Suppression in Sweet Corn

Modern vegetable production systems are often characterized by monoculture fields and the intensive use of tillage and/or synthetic agrochemicals for managing weeds. A growing public interest in more sustainable and eco-friendly production practices has resulted in increased demand for crops to be produced with lower inputs. Field studies were conducted over three field seasons to investigate the use of conservation tillage in concert with an interplanted living mulch and/or cover crop residue for managing weeds in sweet corn as compared with the standard practice of using conventional tillage and pre-emergence residual herbicides. Whole plot treatments included: (1) conventional till, (2) no-till with cover crop residue, (3) living mulch + cover crop residue, and (4) living mulch + winter killed residue. The split-plot factor consisted of herbicide treatments: (1) at-planting application of residual herbicides or (2) no herbicide. The cover crop systems suppressed weeds as well as the standard practice throughout the cropping cycle in all three years. In addition, there was no significant improvement in weed suppression with the application of herbicides within the cover crop treatments. Crop development and yield were similar among treatments in year 2. However, reduced yields were encountered in all cover crop treatments during year 3 relative to the conventional tillage treatment.