Relationship between seed dormancy and persistence of seeds of annual ruderal species in the soil seedbank

Knowledge related to seed persistence in soil is critical for weed control decisions in the integrated weed management systems. Many annual weed species have dormant soil seed banks (SSBs), and this may be an important mechanism for seed persistence in these species. Although the relationship between seed dormancy and persistence in soil has received previous attention, it has not been well characterized. In order to quantify the relationship between seed persistence and dormancy, a five-year seedbank dynamics field study was conducted in Savoy, IL, involving twelve ruderal weed species: Abutilon theophrasti, Alliaria petiolata, Amata tuberculatus, Ambrosia trifida, Chenopodium album, Ipomoea hederacea, Kochia scoparia, Panicum miliaceae, Polygonum pensylvanicum, Setaria faberi, Setaria lutescens, and Thlaspi arvense. Seed half-lives (t0.5) in the SSB ranged from 0.25 to 2.22 years for the study species. Seed dormancy showed a positive linear relationship to t0.5 (slope = 0.050, p < 0.001, R2 = 0.92), while the variance of seed dormancy followed a negative nonlinear relationship with t0.5. No relationship between environmental conditions during the course of seed burial and seed dormancy across study years was detected. These results indicate a strong relationship between the dormancy and persistence of seeds of ruderal weed species in the soil seedbank. Moreover, they suggest that dormancy release for these species was at least partially controlled by intrinsic seed characteristics. Findings of this study will facilitate the determination of seed persistence and management of the SSB in integrated weed management