Current knowledge of the biology of Picris willkommii and his grade of threat, seem not to be sufficient to ensure longterm persistence of this plant species endemic to the South-Western Iberian Peninsula. In Spain, main populations of the species are narrowly restricted to therophytic grasslands around the town of Ayamonte, by the Guadiana river drainage. Results of the present study indicate that P. willkommii behaves as a very versatile, colonizing species in most of the habitats of their natural range, where it appears to be well suited to the cyclic disturbance dynamics imposed by local, traditional land uses, i.e. extensive rain-fed agriculture. Moreover, it is easy to grow under controlled conditions. Results could be helpful for conservation and population recovery purposes, as recent changes in land use, shifting from agricultural traditional systems to urban expansion or alternative agricultural systems, pose at risk P. willkommii populations due to habitat loss.
Aim of study: A predictive model of the seedling emergence pattern of Phalaris brachystachys Link (short-spiked canary grass) was developed, aimed to contribute to support a more efficient management of this troublesome, competitive weed in winter cereal crops around its native Mediterranean range and in different areas of the world where it is introduced. Area of study: Southern (Andalusia) and northern Spain (Navarra). Material and methods: A model describing the emergence pattern of P. brachystachys in cereal fields based on accumulation of hydrothermal time in soil was developed and validated. For model development, cumulative emergence data were obtained in an experimental field, while an independent validation of the model was conducted with data collected in two commercial wheat fields from climatically contrasting regions of Spain. Main results: The relationship between cumulative emergence and cumulative hydrothermal time (CHT) was well described by a Logistic model. According to model predictions, 50% and 95% seedling emergence takes place at 108 and 160 CHT above base water potential for seed germination, respectively. The model accurately predicted the seedling emergence time course of P. brachystachys in the two commercial wheat fields (R2 ≥ 0.92). Research highlights: This model is a new tool that may be useful to improve the timing of control measures to maximize efficiency in reducing P. brachystachys infestations in cereal crops.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.