Germination of chloris barbata, cynodon dactylon, and cyperus rotundus from Angola at constant and alternate temperatures

The study of weed germination can improve knowledge on their seasonal dynamics in fields and facilitate the design of ecologically sustainable management. An experiment was conducted to evaluate the effect of a range of constant and alternate temperatures on the germination of Chloris barbata, Cynodon dactylon, and Cyperus rotundus collected in Angola. Interesting differences were observed between the germination responses of the three species. No germination was observed for any species at 10 or 15 - 5 °C. Chloris barbata quickly germinated at most constant and alternate incubation temperatures, showing low primary dormancy and high germinability. Fast and high germination was observed for Cynodon dactylon at most alternate temperatures, while lower germination percentages were achieved at constant temperatures, especially the highest ones. Cyperus rotundus achieved good germination percentage at alternate temperatures, even if with slower and more extended germination dynamics than the other species, while almost no seeds germinated at constant temperatures. This study improves our knowledge of germination ecology for these species and allows some control tools to be identified, such as soil tillage, cover crops, and living or dead mulches, which can contribute to their ecologically sustainable management.