@article{sousa-ortega_leon_lopez-martinez_castro-valdecantos_2023, title={Influence of burial depth and soil disturbance on the emergence of common weed species in the Iberian Peninsula}, volume={5}, url={https://doi.org/10.1017/wsc.2023.30}, DOI={10.1017/wsc.2023.30}, abstractNote={Abstract North African knapweed ( Centaurea diluta Aiton), cornflower ( Centaurea cyanus L.), corn marigold [ Glebionis segetum (L.) Fourr.], rigid ryegrass ( Lolium rigidum Gaudin), and corn poppy ( Papaver rhoeas L.) are weeds of economic importance in the Iberian Peninsula, particularly due to limited herbicide options for effective control. For this reason, information about their seedling emergence has become critical to develop effective integrated management strategies and better time control actions. The aims of this study were to evaluate the effect of seed burial depth and soil disturbance on the emergence of these weed species. Two pot experiments were carried out to (1) quantify seedling emergence at three burial depths (2, 5, and 9 cm) and (2) characterize seedling emergence in response to different frequencies and timings of soil disturbance. Burial depth limited the emergence of G. segetum and P. rhoeas at 5 and 9 cm, respectively; while seedling emergence of C. diluta , C. cyanus , and L. rigidum were reduced by 92%, 90%, and 67% at 9 cm compared with 2 cm, respectively. Two or more sequential soil disturbance events increased total seedling emergence of C. diluta , P. rhoeas , and G. segetum compared with single events, while L. rigidum did not respond to repeated soil disturbance. These results suggest that turning the soil to bury weed seeds down to 5 cm or deeper would be a very effective method to control G. segetum and P. rhoeas and moderately effective to control C. cyanus . Also, the use of a stale seedbed would have some efficacy to reduce P. rhoeas and C. diluta weed pressure within the crop. This study illustrates how differences among species in seedling emergence in response to soil depth and disturbance can determine distinct emergence patterns ultimately influencing the selection of weed control tools and timing.}, journal={Weed Science}, author={Sousa-Ortega, Carlos and Leon, Ramon G. and Lopez-Martinez, Nuria and Castro-Valdecantos, Pedro}, year={2023}, month={May} }
 @article{sousa‐ortega_alcántara_leon_barranco‐elena_saavedra_2023, title={The impact of burial depth on <i>Centaurea diluta</i> emergence and modelling of its growth using a nonlinear regression and artificial neural network}, volume={11}, url={https://doi.org/10.1002/ps.7848}, DOI={10.1002/ps.7848}, abstractNote={Abstract BACKGROUND Centaurea diluta Aiton (North African knapweed) is a major weed concern in Spain as a result of the limited herbicides capable of controlling it, and the limited knowledge of its biology hinders the development of integrated weed management strategies. RESULTS The current study presents results from two experiments that aimed to: (i) determine the effect of seed burial on seedling emergence; and (ii) model its phenology progression using sigmoidal (SRM) and artificial neural network models (ANN) based on different cohort emergence times. In the first experiment, burial at 2 cm and 5 cm decreased C. diluta emergence by 54% and 90%, respectively, compared to the emergence at 0 cm. In the second experiment, without crop–weed competition conditions, the emergence delay led to reductions in leaf number, rosette diameter, plant height and dry biomass by 63%, 50%, 59% and 93%, respectively. Seed production per plant exceeded 21 469. According to the growth model, leaf number was the most consistent morphological trait and critical for timing weed control actions, so it was used to compare SRMs and ANNs. On average, ANNs increased the precision in 5.72% (± 2.4 leaves) compared to SRMs. This slight performance of ANNs may be valuable for controlling C. diluta because control methods must be applied at the 4‐leaf stage to achieve good efficacy. CONCLUSION Seed burial at 5 cm depth is an effective method reducing C. diluta emergence. ANNs accurately predicted the leaf number employing environmental variables can help increase the efficiency of C. diluta control actions and reduce the risk of escapes. © 2023 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.}, journal={Pest Management Science}, author={Sousa‐Ortega, Carlos and Alcántara, Cristina and Leon, Ramon G and Barranco‐Elena, Diego and Saavedra, Milagros}, year={2023}, month={Oct} }