Search results for "root rot"
showing 8 items of 18 documents
First Report of Phytophthora spp. as Pathogens of Pandorea jasminoides in Italy
2019
In the summer of 2005, approximately 5% of a nursery stock of 12-month-old potted plants of bower vine (Pandorea jasminoides (Lindl.) K. Schum.) in Sicily (Italy) showed wilt, leaf chlorosis, defoliation, root rot, and collapse of the entire plant. Three Phytophthora spp. (20, 50, and 30% of the isolations of the first, second, and third species, respectively) were isolated from rotted roots on BNPRAH selective medium (2). Single-hypha isolates of the first species formed petaloid colonies on potato dextrose agar (PDA) and had an optimum growth temperature of 25°C (9.3 mm/day); on V8 juice agar, they produced uni- and bipapillate, ovoid to limoniform sporangia with mean dimensions of 45 × …
First report of Phytophthora palmivora on Coronilla valentina subsp. glauca in Italy
2019
The genus Coronilla L. (family Fabaceae), which includes several species native to central and southern Europe, such as C. varia L. (axseed or crown-vetch), C. emerus (scorpion senna), and C. valentina L., is used in Italy as a landscape shrub or potted ornamental plant. During the summer of 2001, 80% of approximately 10,000 1-year-old plants of C. valentina subsp. glauca (L.) Batt. used to landscape an industrial area in the Caltanissetta Province (Sicily) showed symptoms of dieback associated with basal stem and root rot. Plants had been transplanted from pots in April and watered using a trickle irrigation system. A species of Phytophthora was isolated consistently from rotted roots and…
Pea root rot diseases : characterization and biocontrol of the disease complex including Aphanomyces euteiches.
2021
Root rots in peas are a major concern in most growing regions around the world. The disease is caused by a parasitic complex made up of many species of soil-borne fungi and oomycetes. In France, the main pathogen involved until recently was the oomycete Aphanomyces euteiches. The identity of the other components of the parasitic complex and their respective contributions to the disease have not been investigated. No control method is currently available to effectively control the disease, apart from a predictive biological test questioned by some users. However, this test allows the avoidance of infested plots, which furthermore limits the multiplication in soils of A. euteiches, i.e. the m…
Les pourritures racinaires du pois potager, caractérisation et biocontrôle du complexe parasitaire d’origine tellurique incluant Aphanomyces euteiches
2021
Pea root rots are a major concern for pea growing regions around the world. The disease is caused by a parasitic complex composed of many species of fungi and oomycetes of soil origin. In France, the main pathogen is the oomycete Aphanomyces euteiches. The identity of the other components of the parasitic complex and their respective contributions to the disease have never been investigated. No means of control is currently available to effectively control the disease except for a predictive bioassay that is questioned by some users. However, this test allows the avoidance of infested plots, which limits the multiplication of the major pathogen A. euteiches in the soil. In this context, the…
Blight of English Ivy (Hedera helix) caused by Sclerotium rolfsii in Sicily
2007
English ivy, Hedera helix L. (Araliaceae), an evergreen climbing vine is widely cultivated as an ornamental and foliage plant. In the summer of 2005, a severe blight of ivy plants trained as topiaries and grown in an open field was observed in a nursery near Giarre (eastern Sicily). Foliage of infected plants appeared lighter green and progressively turned bronze and withered. Eventually, the entire plant collapsed. Foliar symptoms were associated with basal stem and root rot. White, cottony mycelium and numerous sclerotia developed externally on the lower stem and on the soil around the affected plants. The disease was randomly distributed, affecting approximately 5% of plants in a stock …
Root and Basal Stem Rot of Rose Caused by Phytophthora citrophthora in Italy
2011
Approximately 800 ha of cut flower roses are cultivated for commercial production in Italy. During autumn of 2004 in an experimental greenhouse in western Sicily (southern Italy), 60% of 2-year-old plants of rose cv. Red France on Rosa indica cv. Major rootstock grown in soil showed leaf chlorosis and wilt. A dark brown lesion lined by a water-soaked area was noticeable at the stem base near the soil surface. Root rot was found consistently associated with aboveground symptoms and plants collapsed within 4 months after the appearance of the first symptoms. The same symptoms were observed sporadically on rose plants of the same cultivar during the last 6 years in commercial nurseries in wes…
Differentiation of the Disease Caused by Aphanomyces cochlioides and Girth Scab on Sugar Beet Roots – a Review
2017
Severe symptoms of root rot on sugar beet have been observed in Poland and Germany since 2001. The symptom classification suggested girth scab as it was mistakenly classified on the basis of current classification, e.g. in LIZ. However, the cause of the disease was Aphanomyces cochlioides infection, not Streptomyces spp. According to these findings we cannot call the symptoms caused by A. cochlioides as ‘girth scab’. The typical scab (girth scab) symptoms can be promoted by A. cochlioides infections. In many cases, A. cochlioides developed at the beginning of the season, during the seedling stage. Its further development was due to rainfall and was not routinely recognised in disease-change…