Abstract: Buried feral rye seeds were rapidly depleted in soil in the first year due to in situ germination. Less than 1% of the viable seeds persisted after 45 mo of burial. Although after 5 yr, a small number of seedlings still emerged, soil seedbank decline was rapid when seed production was prevented. A low level of induced dormancy was detected and may explain the small populations of feral rye that persisted. Seed and seedling population shifts were large over a 5-yr period and were related to environmental conditions. Tillage or chemical control of feral rye in the fallow period reduced populations compared to the untreated weedy check. Moldboard plowing provided the greatest feral rye control compared to shallow tillage and chemical fallow. Feral rye seedbank populations rebounded following a wet final year of the study. These results help explain feral rye persistence in a wheat–fallow agroecosystem by the persistence of a small portion of the seedbank and by large seed inputs into the system during environmentally favorable years. Feral rye reduced wheat yield as much as 92% and represented up to 73% contamination in harvested wheat.
Nomenclature: Feral rye, Secale cereale L. #3 SECCE.
Additional index words: Volunteer rye, dormancy, population dynamics, seed burial, feral rye management, weed competition.
