Root and crown tot of olive caused dy Phytophthora spp.

Phytophthora root and crown rot has been traditionally considered a minor disease of olive. However, in recent years it has been recognized as an emerging problem in several olive-growing countries such as Australia, Italy and Spain probably as a consequence of the expansion of plantings in new areas with heavy soils and the more intensive use of irrigation in both olive nurseries and commercial groves. The disease has been reported from most olive-growing countries and is caused by several soil -borne species of Phytophthora, including P. cinnamomi, P. citricola, P. cryptogea, P. drechsleri, P. gonapodyides, P. inundata, P. megasperma,P. nicotianae and P.palmivora. Diagnosis is currently based on the isolation and identification of isolates by both traditional and molecular methods. New molecular techniques are currently available that could be applied for both the identification of isolates and Phytophthora infections directly in host-tissues as well as insoil and water samples. A number of dedicated databases could improve the efficiency of these techniques. Moreover, DNA analysis has greatly contributed to phylogenetic studies of Phytophthora. Control of Phytophthora root and crown rot of olive is mainly based on preventive measures

A new approach in the monitoring of the phytosanitary conditions of forests: the case of oak and beech stands in the Sicilian Regional Parks

L'obiettivo del presente studio è stato quello di esaminare lo stato fitosanitario delle quercete e faggete dei tre Parchi Regionali Siciliani (Parco dell'Etna, Parco delle Madonie, Parco dei Nebrodi). Lo studio è stato condotto individuando delle aree di saggio, popolamenti forestali omogenei sotto l'aspetto floristico, ecologico e fitosanitario. Complessivamente sono state delimitate 81 aree di saggio, di cui 54 quercete e 27 faggete. La condizione fitosanitaria di ogni essenza arborea all'interno della rispettiva area di saggio è stata espressa con un indice numerico denominato “classe fitosanitaria” (PC). I popolamenti di quercia hanno mostrato un elevato grado di sofferenza, con alberi sintomatici nell’85% delle aree di saggio. I popolamenti di faggio hanno mostrato una situazione di maggiore stabilità, ad eccezione delle faggete del parco dei Nebrodi che apparivano molto degradate. Sul genere Quercus, sono stati osservati sintomi di infezioni di patogeni fungini comuni nelle foreste delle aree temperate e Mediterranee, quali Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides ed Armillaria sp., mentre su faggio sono state osservate infezioni di Biscogniauxia nummularia, Fomes fomentarius e Neonectria radicicola. Sono state altresì individuate 22 aree che vengono proposte come aree di saggio permanenti dello stato fitosanitario delle foreste nei tre parchi.The objective of this study was to investigate the health conditions of oak and beech stands in the three Regional Parks of Sicily (Etna, Madonie and Nebrodi). A total of 81 sampling areas were investigated, 54 in oak stands and 27 in beech stands. The phytosanitary conditions of each tree within the respective sampling area was expressed with a synthetic index namely phytosanitary class (PC). Oak stands showed severe symptoms of decline, with 85% of the sampling areas including symptomatic trees. In general, beech stands were in better condition, with the exception of Nebrodi Park, where trees showed severe symptoms of decline. On oak trees, infections of fungal pathogens were also observed, including Biscogniauxia mediterranea, Polyporus sp., Fistulina hepatica, Mycrosphaera alphitoides and Armillaria sp. By contrast, on beech trees Biscogniauxia nummularia, Fomes fomentarius and Neonectria radicicola were recognized. Furthermore, twenty-two permanent sampling areas were delimited with the aim of monitoring regularly the health conditions of forests in these three parks

Efficacia del Valifenalate contro specie terricole di Phytophthora patogene di piante ornamentali

I risultati confermano che il valifenalate su piante erbacee e arbustive è un prodotto sistemico e dimostrano che questo p.a., proposto come antiperonosporico, può essere efficace anche contro i marciumi radicali di piante ornamentali causate da specie terricole di Phytophthora

Efficacy of the fungicide valiphenal against crown rot of rose caused by Phytophthora citrophthora

Crown and root rot caused by soilborne species of Phytophthora are common diseases of container-grown ornamental plants in nursery. Crown rot of Rose caused by P. citrophthora has been recently reported in Sicily (southern Italy). Valiphenal (IR 5885) is a systemic dipeptide fungicide of the valinamide class of compounds and is active against Oomycetes. This new fungicide is under development by the italian agrochemical company ISAGRO against powdery mildews of grapevine, potatoes and vegetables. In this study, the efficacy of Valiphenal and other experimental active ingredients was tested for the first time against crown rot of Rose. Phosetyl-Al (Aliette) was used as a reference product. Minigreffe plants of ‘Red France’ Rose on Rosa indica-major as rootstck, grown in pots (diameter 16 cm) in a plastic-house were used in all experiments. Plants were wound inoculated on the stem with agar plugs taken from P. citrophthora colonies growing on potato dextrose agar. Wounds were sealed with Parafilm and symptoms were evaluated at various time intervals after inoculation. Valiphenal, alone or mixed with biostimulants, such as the leaf organic fertilizer Siapton, was applied as foliar spray at the dose of 0.75 g/l a. i., 7 days before the inoculation. In all experiments Valiphenal proved to be as effective as Phosetyl-Al in reducing the length of the cankers on the stems of inoculated plants. Five months after the inoculation, plants treated with Valiphenal or Phosetyl-Al did not show symtoms of stem dieback whereas all nontreated control plants wilted. The addition of Siapton increased the efficacy of Valiphenal but results were not consistent among experiments. No symptoms of phytotoxicity were observed on treated plants