Hydraulic shock waves were introduced into plants by pruning. These shock waves were monitored by a sap flux meter attached to the plant at some distance from the excision. The measured shock waves ...occurred a short time after pruning. An electrical analogy is proposed to explain the time lags. The analogy suggested that, in plants undergoing auto-oscillatory behaviour, there should be a time lag in the transmission of oscillations in sap flux along a stem. A plant undergoing auto-oscillatory water metabolism showed a time lag of this type.
The development of Azotobacter chroococcum is promoted in the ivy (Hedera helix L.) rhizosphere when it is colonized by the pectinolytic mold Mucor fragilis. The multiplication of Azotobacter cells ...in the mineral solution of ivy cultures induces a decrease of the amount of sugars excreted by the roots and a increase of the amount of nitrogen. Within the experimental period Azotobacter does not influence the growth of ivy roots although it seems to be promoted by Mucor. Filtrates of Mucor culture are, however, harmful to the plant.
Certaines des plantes rencontrees en espaces verts ont des fruits colores, baies, arilles ou capsules, presentant une certaine toxicite. L'article evoque les vegetaux les plus souvent recenses au ...Centre anti-poison d'Angers comme a l'origine d'intoxications. Il donne des elements de description botanique pour faciliter leur reconnaissance et quelques conseils de prudence. Le choix d'emplacement et/ou de tailles appropriees peuvent ainsi limiter les risques en empechant la fructification ou en la limitant a des zones inaccessibles notamment aux enfants
