Factors Influencing the Field Germination of Forage Kochia

ABSTRACTForage kochia (Bassia prostrata) is a drought and salt tolerant perennial, semi‐shrub that has proven to be valuable forage in the western United States, but can be difficult to reliably establish. This study evaluated the effects that forage kochia entry (accession and seed lot combinations) and planting date have on forage kochia seed germination in the field. Evaluated were recently harvested and cold‐stored, year‐old seed from one accession each of Bassia prostrata subspecies virescens and grisea. Planting was simulated by placing seed packets at ground level, at two Utah locations, once each month mid‐January through mid‐April. Subsequently, seed packets were retrieved every 15 d until 75 d after planting (DAP) to determine the amount of seed that had germinated. Forage kochia germination was affected (P < 0.05) by the accession and seed lot combination and planting date. At 45 DAP, when germination was at or near maximum, recently harvested seed of subspecies grisea had field germination of 84, 96, 80, and 28% compared with virescens germination of 59, 55, 27, and 14% for planting dates in January, February, March, and April, respectively. Year‐old seed of both subspecies had much lower field germination of 13, 14, 10, and 7% for grisea and 6, 9, 0, and 0% for virescens during the same planting dates of January through April. These results confirm that seeding in January or February using recently harvested seed of subspecies grisea promotes forage kochia germination and increases the likelihood of successful stand establishment.