Influence of Flooding Period and Seed Burial Depth on Palmer amaranth (Amaranthus palmeri) Seed Germination.

BACKGROUND Flooding throughout fall and winter months is an effective practice for rice (Oryza sativaL.) straw decomposition, soil seedbank depletion, and waterfowl habitat in Mississippi. Nevertheless, limited research is available regarding the effects of fall-winter flooding and seed burial depth on Palmer amaranth (Amaranthus palmeriS. Wats.) seed germination. The objective of this study was to evaluate the effect of flooding period and seed burial depth onA. palmeriseed damage and germination in three different soil textures in Mississippi. RESULTS Amaranthus palmeriseed damage was greater when seeds were buried in sandy loam compared to silt loam soil textures. An interaction between flooding period and seed burial depth was present forA. palmeriseed germination. Flooding periods of 1-month (at 0 and 15 cm burial depth) and 2 months (at 0 cm burial depth) provided similarA. palmeriseed germination compared to no-flooding (at 0 cm burial depth). In addition, flooding periods of 3, 4, and 5 months reducedA. palmeriseed germination by 10, 10 and 14 percentage points at 0 cm burial depth, and 36, 40, and 41 percentage points when seeds were buried at 15 cm, respectively, across all soil textures. CONCLUSION This research demonstrates that flooding for 3, 4, and 5-months throughout fall and winter is an effective cultural practice to increase soil seedbank depletion through reduced germination potential to help manage herbicide-resistantA. palmeripopulations in sandy loam, silt, and silt loam soil textures.