0000000000787660
AUTHOR
Guido De Marchi
Pre-main sequence stars older than 8 Myr in the Eagle Nebula
Attention is given to a population of 110 stars in the NGC 6611 cluster of the Eagle Nebula that have prominent near-infrared (NIR) excess and optical colours typical of pre-main sequence (PMS) stars older than 8 Myr. At least half of those for which spectroscopy exists have a Halpha emission line profile revealing active accretion. In principle, the V-I colours of all these stars would be consistent with those of young PMS objects (< 1 Myr) whose radiation is heavily obscured by a circumstellar disc seen at high inclination and in small part scattered towards the observer by the back side of the disc. However, using theoretical models it is shown here that objects of this type can only …
First Report of Diaporthe eres Associated with Cane Blight of Grapevine (Vitis vinifera) in Italy
In March 2014, in a ‘Trebbiano’ vineyard in the province of Florence (Tuscany, Italy), 15% of the grapevines (Vitis vinifera L.) showed 1-year old canes with bleached areas, sometimes surrounded by dark margins, irregular dark blotches, and several dead buds. Canes were covered by black pycnidia, and occasionally cracks on the cortex were evident. Woody tissues under the bark were necrotic and canes broke easily. Fifteen symptomatic canes were collected from different vines and cane segments of 20 cm length were placed in a moist chamber and incubated at 25°C. After 72 h, a cream-white cirri mass of conidia was observed from pycnidia and it was plated onto potato dextrose agar (PDA) plates.…