Search results for "root rot"
showing 10 items of 18 documents
Root rot of pea: characterization and biocontrol of the soil-borne disease complex including Aphanomyces euteiches
2018
Pea root rot is an increasing constraint in most of intensive pea cropping areas across the globe. The pathogenic complex responsible for the disease is composed of soil-borne fungal and oomycete pathogens such as Fusarium solani, F.oxysporum, F. avenaceum, F. culmorum, Rhizoctonia solani, Thielaviopsis basicola, Ascochyta pinodella, Pythium spp., Aphanomyces euteiches and probably others not yet identified. The diversity of their ecological and pathogenic properties can explain the worldwide dispersion of the disease and the absence of chemical, agricultural or genetic control tools. My research program aims at characterizing the parasitic consortium occurring in the North of France and at…
Resistance of Phytophthora capsici to metalaxyl in plastic-house capsicum crops in southern Italy
2000
In Calabria (southern Italy), control of crown and root rot of capsicum caused by Phytophthora capsici has relied primarily on soil drenches of metalaxyl. However, severe outbreaks occur every year in glasshouse crops, in which the practice of using plastic mulch and furrow irrigation favours the disease. Single-hypha isolates of P. capsici collected in Calabria in 1992/1998 were tested in vitro for their level of sensitivity to metalaxyl. Isolates of other species of Phytophthora were used as reference. Fungicide sensitivity was determined by plating mycelial plugs onto potato dextrose agar amended with metalaxyl, at final concentrations ranging from 0.1 to 1000μg mL−1 a.s. Inhibition of r…
Phytophthora palmivora a New Pathogen of Lavender in Italy
2019
Root rot caused by Phytophthora nicotianae is considered the most serious disease of lavender in commercial cultivations in Italy. In summer 2001, in the Gela area (Sicily), ≈60% of 34,000 2-year-old landscape shrubs of English lavender (L. angustifolia) grown in a clay loam soil showed symptoms of dieback associated with root rot. Plants had been transplanted from pots in May and watered using a trickle irrigation system. A species of Phytophthora was isolated consistently from roots of symptomatic plants using potato dextrose agar (PDA) containing benomyl, nystatin, pentachloronitrobenzene, rifampicin, ampicillin, and hymexazol. The species was identified as P. palmivora on the basis of …
Infection and spread of root rot caused byHeterobasidionspp. inPinus contortaplantations in Northern Europe: three case studies
2019
This study investigated the origins and spread patterns of Heterobasidion root disease in three Pinus contorta Dougl. ex Loudon plantations established on forest and agricultural land and subjected to three different management scenarios. Trees with decline symptoms and stumps remaining from the previous rotation were sampled for fungal isolations. Ten isolates of Heterobasidion parviporum Niemelä & Korhonen and 425 of Heterobasidion annosum (Fr.) Bref. were tested for clonality through somatic compatibility tests. The following conclusions were reached: (i) P. contorta is highly susceptible to H. annosum and H. parviporum and both pathogens cause dieback of P. contorta; (ii) H. annosum…
First report of Phytophthora palmivora as a pathogen of olive in Italy
2000
Olive (Olea europea L.) is an economically important crop in Italy and is planted on about 1 million ha. The Apulia, Calabria, and Sicily regions of Southern Italy account for about 70% of the production. Many new plantations have been established during the last 10 years. In summer 1999, 1- to 2-year-old olive trees (cv. Carolea) with decline symptoms were observed in new plantations in Catanzaro Province (Calabria). The symptoms associated with the root rot were leaf chlorosis, defoliation, wilting, twig dieback, and eventual plant collapse. In some cases, more than 40% of the trees were affected. A Phytophthora sp. was isolated consistently from rotted rootlets of diseased trees using a…
Phytophthora species causing crown and root rot of tomato in southern Italy
2000
Phytophthora capsici, Phytophthora cryptogea and Phytophthora nicotianae were isolated from tomato plants with symptoms of crown and root rot in plastic-house crops in Sicilia and Calabria (southern Italy). The species were identified primarily on the basis of morphological and cultural characteristics. The identification was confirmed using molecular methods, polyacrylamide gel electrophoresis (PAGE) of mycelial proteins and polymorphism of DNA sequences amplified by polymerase chain reaction using random primers (RAPD-PCR). P. capsici caused significant losses in tomato crops that had succeeded capsicum crops. P. cryptogea was found to be the most frequent species causing basal stem rot o…
First report of root and crown rot of sage caused by Phytophthora cryptogea in Italy
2019
Sages are cultivated as aromatic and ornamental plants in Italy and represent the common name of certain species of Salvia and Phlomis (family Lamiaceae). In Sicily (southern Italy) during the summer of 2001, ≈40% of 1,400 2-year-old landscape plants of S. leucantha Cav. (Mexican bush sage or velvet sage) showed symptoms of stunting, chlorosis, and gradual dieback or sudden wilt, which are associated with root and crown rot. Plants were supplied by a commercial nursery, transplanted from pots in the spring, and irrigated using a trickle system. Phytophthora was isolated consistently from roots and basal stems of symptomatic plants on a BNPRAH medium (2). The species was identified as P. cr…
Phytophthora Root and Collar Rot of Paulownia, a New Disease for Europe
2021
Paulownia species are fast growing trees native to China, which are being grown in managed plantings in several European countries for the production of wood and biomasses. In 2018, wilting, stunting, leaf yellowing, and collapse, as a consequence of root and crown rot, were observed in around 40% of trees of a 2-year-old planting of Paulownia elongata × P. fortunei in Calabria (Southern Italy). Two species of Phytophthora were consistently recovered from roots, basal stem bark, and rhizosphere soil of symptomatic trees and were identified as Ph. nicotianae and Ph. palmivora on the basis of both morphological characteristics and phylogenetic analysis of rDNA ITS sequences. Koch’s postulates…
Collar and root rot of olive trees caused by Phytophthora megasperma in Sicily
2019
Olive (Olea europea L.) is grown on about 154,000 ha in Sicily (southern Italy). In the summer of 1999, a few 3-year-old olive trees with decline symptoms were observed in a recently planted commercial orchard in the Enna province (Sicily). The trees were propagated on wild olive (O. europea L. var. sylvestris Brot.) rootstock. Aerial symptoms, consisting of leaf chlorosis, wilting, defoliation, and twig dieback followed in most cases by plant death, were associated with root rot and basal stem cankers. A Phytophthora sp. was consistently isolated from rotted rootlets and trunk cankers using the BNPRAH (benomyl, nystatin, pentachloronitrobenzene, rifampicin, ampicillin, and hymexazol) sele…
Root rot of pea : characterization and biocontrol of the soil-borne disease complex including Aphanomyces euteiches
2018
Pea root rot is an increasing constraint in most of intensive pea cropping areas across the globe. The pathogenic complex responsible for the disease is composed of soil-borne fungal and oomycete pathogens such as Fusarium solani, F.oxysporum, F. avenaceum, F. culmorum, Rhizoctonia solani, Thielaviopsis basicola, Ascochyta pinodella, Pythium spp., Aphanomyces euteiches and probably others not yet identified. The diversity of their ecological and pathogenic properties can explain the worldwide dispersion of the disease and the absence of chemical, agricultural or genetic control tools. My research program aims at characterizing the parasitic consortium occurring in the North of France and at…