Identification of Phytophthora species infecting citrus in Vietnam

In a survey aimed at identifying Phytophthora species infecting fruit crops in Viet Nam, P. citrophthora and P. nicotianae were the species most commonly recovered from soil and trees in citrus plantations. P. nicotianae was prevalent in citrus groves in the Ben Tre and Tien Giang provinces (southern Viet Nam). Interestingly, both A1 and A2 mating types of the latter species were found, while in other citrus-growing areas of the world, such as the Mediterranean region, South Africa, Australia and the Americas, A1 is the only mating type occurring in citrus groves, suggesting southern-east Asia could be a centre of origin of this Phytophthora species. Mixed infections of three Phytophthora s…

Root and Basal Stem Rot of Scotch Broom Caused by Phytophthora citricola and P. drechsleri in Italy.

Scotch broom (Cytisus scoparius (L.) Link, Fabaceae), an evergreen shrub native to Europe, is cultivated as a garden plant. In 2003 and 2004, potted plants with symptoms of leaf chlorosis, defoliation, and eventual wilt and associated with root and collar rot were observed in ornamental nurseries in Sicily. As much as 10% of plants were affected in a single nursery. Two species of Phytophthora were consistently isolated alone or together from the same pot with the selective medium of Masago et al. (2). Pure cultures were obtained by single-hypha transfers and the species were identified as P. citricola Sawada (approximately 40% of isolations) and P. drechsleri Tucker (60% of isolations) on…

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. M…

Root and crown rot of olive caused by Phytophthora spp

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 b…