The effect of weed management that targets the seed stage on subsequent life stages is largely unknown. Post-dispersal seed predation reduces the number of seeds from the soil surface before the seeds contribute to the seedbank. Density-dependent processes can mitigate the effect of seed predation in subsequent life stages. In this study, we tested if (i) targeting the seed stage affects the subsequent seedling stage; (ii) if density-dependent mortality in subsequent life stages partly compensates seedling abundance; and (iii) if the magnitude of final seed production depends on seed predation. We fully parameterized a model for the summer-annual weed Echinochloa crus-galli (L.) P. Beauv. Field data from three maize fields in north-eastern Germany were obtained, in the presence or absence of seed predation and different population levels of the weed species. Seeds of E. crus-galli were applied in autumn and the number of seedlings, adult plants, and seed production per m² was determined the following season. Seed predation reduced the number of seedlings. Density-dependent mortality during the seedling stage increased fecundity with decreasing seedling density, and, thus, compensated for lower numbers of seedlings. The final level of seed production per m² did not depend on seed predation and initial population densities, but differed among fields. We conclude, solely targeting the seed stage can scarcely limit the population growth of E. crus-galli.

Effective cultivation of the potential rubber crop Taraxacum kok-saghyz (TKS) is hindered by weed competition, which can lead to substantial yield losses. A major challenge is the absence of effective weed control tools, specifically designed for TKS, in contrast to the situation that is available for major crops. Consequently, residual weed populations often remain, thereby exacerbating competition. A promising solution is the development of more targeted weed management strategies that focus on the competition ability of specific weed species or density thresholds. This study is the first to investigate the effect of two contrasting weed species, Viola arvensis (low competitive) and Chenopodium album (high competitive), on rubber yield using pot experiments on two sites. Results indicate that rubber yield is significantly affected by the weed species. In the presence of V. arvensis, higher yields (0.02 g/plant in Brunswick and 0.01 g/plant in Quedlinburg) were observed than in the presence of C. album or a mixture of both species (0.001–0.01 g/plant), with a strong site effect. This study reveals that rubber yield was independent of increasing weed densities. However, it was dependent on decreasing dry matter and increasing rubber content. The results suggest that managing weeds in TKS depends on the weed species, thus necessitating the development of species-specific weed management strategies in future research agendas.

To mitigate supply risks associated with Hevea brasiliensis, Taraxacum kok-saghyz is being developed as a promising temperate source of natural rubber. For it to be successfully integrated into conventional cropping systems, optimized agronomic practices are required. The present study investigates the effects of sowing season (spring vs. autumn) and harvest timing (June–October) on rubber yield, determined by root dry weight and rubber content. Field trials were conducted at two contrasting locations in Germany using wild-type T. kok-saghyz and the interspecific hybrid ‘Hyb207’. Root dry weight accumulation was influenced by genotype, sowing season, harvest date and site conditions. Despite this variability, autumn sowing increased modeled root dry weight by approximately 81% and rubber content by 84% on average compared to spring sowing. In addition, autumn-sown plants reached peak root dry weight earlier in the season than their spring-sown counterparts. These results demonstrate that strategic selection of sowing and harvest windows is critical for optimizing yield formation. Site-specific management strategies can enhance biomass production and facilitate the integration of Tks into temperate cropping systems.