Fungi were isolated in pure cultures from decaying giant sequoias in Geneva (Switzerland). Isolates were genetically identified by ITS rDNA sequencing. Young giant sequoia trees were artificially infected with a pure culture of Botryosphaeria parva. Henle-Koch’s Postulates demonstrated that Botryosphaeria parva was pathogenic to Sequoiadendron giganteum. When analysing the microorganisms associated to canker and dieback symptoms in a giant sequoias (Sequoiadendron giganteum) in Geneva, the fungus Neofusicoccum parvum (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, teleomorph Botryosphaeria parva (Pennycook & Samuels) Crous, Slippers & A.J.L. Phillips, was isolated, whereas such symptoms are commonly associated to Fusicoccum aesculi (teleomorph Botryosphaeria dothidea). These two fungal species belong to the same genus Botryosphaeria of the Botryosphaeriaceae family. Because Neofusicoccum parvum was causing cankers and diebacks in other woody species around the world, we extended the analysis to other trees displaying sequoia dieback symptoms in order to evaluate the involvement of Neofusicoccum parvum in such increasing symptoms in sequoias in Geneva. Dried twigs, trunk, and branch cankers from diseased trees were sampled on several distinct sites. From all samples, isolated fungi in pure cultures showed a phenotype typical of Botryosphaeriaceae species. Isolates were then genetically identified at the species level. Subsequently Neofusicoccum parvum was inoculated to young giant sequoia trees, re-isolated in pure culture from provoked symptoms, and re-identified to fulfil Henle-Koch’s postulates. The identification confirmed that Neofusicoccum parvum was present on all sites, while Fusicoccum aesculi was retrieved only once alone. The inoculation of Neofusicoccum parvum isolates on young sequoias demonstrated for the first time that this fungus was able to develop cankers in Sequoiadendron gigantean. Neofusicoccum parvum could, therefore, be the major cause for dying of giant sequoias in the Geneva Lake area.

Plant growth-promoting rhizobacteria (PGPR) include species in the genera Bacillus, Paenibacillus, and Pseudomonas. We report here the draft genome sequences of the strains Pseudomonas koreensis UASWS1668 and Bacillus megaterium UASWS1667, isolated from a horse chestnut tree, and Paenibacillus sp. strain UASWS1643, isolated from a tomato stem. Auxin production and phosphate solubilization were biochemically confirmed.

Any agricultural production requires the prior production of seeds, carried out by specialized companies, which own in-depth knowledge of seed crops as well as of their pathogens and pests. These pathogens and pests often remain unknown to the agricultural world. They are very little studied and control strategies do not exist. The present study is typical of such a situation: Zollinger Bio, an organic seeds producer, regularly deals with seed crops health problems. Over the last years, the production of seeds of onion (Allium cepa) and leek (Allium ampeloprasum var. porrum) has been reduced by 50% by a bug, morphologically and genetically identified as Carpocoris fuscispinus. Their piercing-sucking mouthparts allow these insects to empty the maturing seeds. Carpocoris fuscispinus, a native bug in Europe, has never been considered as a pest, although observed once as a cereal pest in Iran. The pest has already caused damage during flowering making the use of insecticides not possible, because of their harmful effect on pollinating insects. Entomophagous fungi could be an alternative. Two fungal isolates, Beauveria bassiana UASWS 1427 and Paecilomyces fumosoroseus UASWS 1457, were tested against C. fuscispinus. The experimental units consisted of five bugs in a box with water and food (leek flower, spelled crop seeds). The mortality increased quickly between day four and day eight and reached 100% adults for B. bassiana and 90% for P. fumosoroseus at day eight. Similar results were obtained on larvae. These results are promising of a possible microbiological control against C. fuscispinus.