In some commercial olive groves of Apulia (southern Italy) the occurrence of two new rots of olive fruits (Olea europea L.) was recorded in 1997-2000. The first type of rot was observed on the fruits of cv. Coratina from two orchards in the province of Bari. Its incidence on mature drupes was as high as 60% in the lower tree canopy, symptoms consisting of extensive dark-brown discolorations, often associated with premature falling to the ground. Two different types of Phytophthora spp. were isolated from the lesions of symptomatic fruits, one of which was identified as P. nicotianae (Breda) de Haan. Artificial inoculation of drupes with both colony types reproduced the symptoms after incubation in a moist chamber. The second type of rot was observed on the fruits of cvs Cellina di Nardò and Mele collected from several orchards in the province of Taranto. Rot incidence could reach 20% and symptoms, localised around the pedicel, consisted of shrivelled areas surrounded by a faint yellow halo. From the lesions, a slow-growing fungus was consistently isolated which, based on the morphological characteristics of pycnidia, conidiophores and conidia, was tentatively identified as Pyrenochaeta quercina Kabát & Bubák. Field symptoms were reproduced by artificial inoculation. This is the first record of the occurrence of Phytophthora spp and P. quercina on olive drupes.
Occurrence of new rots of olive drupes in Apulia
NIGRO, Franco;IPPOLITO, Antonio
2002-01-01
Abstract
In some commercial olive groves of Apulia (southern Italy) the occurrence of two new rots of olive fruits (Olea europea L.) was recorded in 1997-2000. The first type of rot was observed on the fruits of cv. Coratina from two orchards in the province of Bari. Its incidence on mature drupes was as high as 60% in the lower tree canopy, symptoms consisting of extensive dark-brown discolorations, often associated with premature falling to the ground. Two different types of Phytophthora spp. were isolated from the lesions of symptomatic fruits, one of which was identified as P. nicotianae (Breda) de Haan. Artificial inoculation of drupes with both colony types reproduced the symptoms after incubation in a moist chamber. The second type of rot was observed on the fruits of cvs Cellina di Nardò and Mele collected from several orchards in the province of Taranto. Rot incidence could reach 20% and symptoms, localised around the pedicel, consisted of shrivelled areas surrounded by a faint yellow halo. From the lesions, a slow-growing fungus was consistently isolated which, based on the morphological characteristics of pycnidia, conidiophores and conidia, was tentatively identified as Pyrenochaeta quercina Kabát & Bubák. Field symptoms were reproduced by artificial inoculation. This is the first record of the occurrence of Phytophthora spp and P. quercina on olive drupes.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
