Residual effects of grass-selective herbicides applied for millet desiccation prior to corn sowing

Background: Corn is a major crop in the world, and weed interference limits yield. While glyphosate‑resistant cultivars have improved control, the selectivity and safety of pre‑sowing desiccation—especially when tank‑mixing glyphosate with grass‑selective herbicides—remain concerns. Objective: To evaluate the optimal interval between desiccation with glyphosate plus haloxyfop or clethodim and corn sowing under no‑till system with millet cover (NTCS) and a conventional system (CS). Methods: A greenhouse trial was conducted in a completely randomized design (four replications) in a 2×4 factorial: soil cover (with millet vs. without) and herbicides (untreated control, glyphosate, glyphosate+clethodim, glyphosate+haloxyfop). Applications occurred 1, 5, 10, and 15 days before sowing (DBS). Plant height, phytotoxicity, and shoot dry mass (SDM) were assessed 28 days after emergence. Results: Shorter plant‑back intervals increased injury and reduced growth. Mixtures with haloxyfop or clethodim caused the greatest damage, mainly at 1 and 5 DBS. No‑till with cover (NTCS) benefited most from the longest interval. Conclusions: Planting at least 15 days after desiccation minimized negative effects, particularly under NTCS.