Curvularia americana and C. tropicalis are described as causes of leaf and crown necroses on Bermuda grass (Cynodon dactylon x Cynodon transvaalensis) in Veneto, Northern Italy. These pathogens were characterized using morphological characters, and a multilocus molecular phylogenetic analysis based on the nuclear ribosomal internal transcribed spacer (ITS) region, the partial glyceraldehyde-3-phosphate dehydrogenase (gapdh) and translation elongation factor-1α (tef1-α) genes. Pathogenicity tests and the fulfilment of Koch’s postulates confirmed C. americana and C. tropicalis as foliar pathogens of Bermuda grass. This is the first report of C. americana and C. tropicalis as pathogens of Bermuda grass, and the first record these two fungi in Europe.

Sclerotinia homoeocarpa F.T. Bennett is one of the most important pathogens affecting high maintenance turfgrass in Italy. Control of this pathogen still relies on the use of fungicides. Twenty nine isolates of S. homoeocarpa collected from 13 different golf courses in northern and central Italy were tested in vitro for their sensitivity to propiconazole, tebuconazole and iprodione, fungicides registered for use on turfgrass in Italy. Three isolates from untreated turfgrasses were use as reference isolates. The tests were carried out on an agar medium amended with 0, 0.01, 0.03, 0.1, 0.3, 1, 3, 10, 30, 100, 300 µg mL–1 of the active ingredient of each fungicide. Most of the isolates showed reduced sensitivity to the tested fungicides, while maintaining their virulence when inoculated on potted Agrostis stolonifera L. Fungicide resistance in this pathogen has increased in Italy compared with the situation 10 years previously.

Pythium blight is one of the most important turf grass diseases. During the past three years, the failure of fungicide treatments against the disease has been observed in several locations in Northern Italy. Twenty Pythium strains collected in nine locations were classified and tested in vitro for their sensitivity to three fungicides, including mefenoxam, fosetyl- aluminium, and propamocarb. Trials were carried out on an agar medium amended with 0, 0.1, 0.3, 1, 3, 10, 30, 100, 300 mg 1 −1 of the active ingredient in each fungicide. Results showed that the different strains belonged to six different species, including P. graminicola , P. aphanidermatum , P. sulcatum , P. arrhenomanes , P. vanterpolii , and P. aristosporum . Among these species, P. sulcatum was never reported on turf grass. In addition, all strains showed reduced sensitivity to in vitro fungicide application.

In the spring and summer of 2002, bermudagrass (Cynodon dactylon × C. transvaalensis) turf in two golf courses located in Sardinia and Apulia (central and southern Italy, respectively) exhibited circular patches that were 10 to 70 cm in diameter. Patches developed in the spring on cv. Santa Ana in Sardinia and cv. Tifway 419 in Apulia, after the turf broke winter dormancy. Although the turf partially recovered during the summer, damage was evident throughout the year in greens, tees, and fairways. Patches coalesced to form large areas of straw-colored, blighted turfgrass. The symptoms observed on single plants resembled those of spring dead spot (SDS), including the presence of root rotting. The upper leaf blades, upper leaf sheaths, and upper culms of the diseased bermudagrass plants were bleached and dessicated, or dead. Infected roots, stolons, and rhizomes were covered with black ectotrophic mycelium. Isolation from infected roots on potato dextrose agar (PDA), supplemented with 100 mg/liter of streptomycin sulfate, consistently yielded a fungus with gray, fluffy, aerial mycelium that was at first light gray and later becoming darker. The maximum daily growth rates of all isolates on PDA ranged from 3 to 4.5 mm at 25°C. The cultural characteristics and growth rates of the isolates corresponded to those described for Ophiosphaerella korrae (4). Pathogenicity tests were performed on 8-week-old C. dactylon × C. transvaalensis (cvs. Santa Ana and Tifway 419) grown in plastic pots (15 × 15 cm). The substrate (sandy soil/sphagnum peat/perlite, 50:35:15) was infested separately with three isolates of O. korrae grown on autoclaved oat kernels, using 10 infested kernels per pot. Three replicates were used. Blight symptoms developed on inoculated plants after 8 weeks. Noninoculated plants remained healthy. The pathogen was consistently reisolated from inoculated plants. The pathogenicity test was carried out twice. SDS incited by O. korrae was reported in Australia (4) and the United States (1,2). To our knowledge, this is the first report of SDS on warm-season turfgrass in Italy, as well as in Europe. SDS continued to be observed in the following years after its first detection (3). In 2006, the disease was observed in Apulia (southern Italy). References: (1) J. N. Crayhay et al. Plant Dis. 72:945, 1988. (2) R. M. Endo et al. Plant Dis. 69:235, 1985 (3) P. Titone et al. Acta Hortic. 661:491, 2004. (4) J. Walker and A. M. Smith. Trans. Br. Mycol. Soc. 58:459, 1972.

Two types of hive-mounted devices for the dissemination of fungal antagonists (Trichoderma harzianum Rifai and Gliocladium virens Miller, Giddens, Foster) of Botrytis cinerea Persoon: Fries were applied to Bombus terrestris (L.) (Hymenoptera Apidae) hives. Their efficacy in contaminating worker bees was assessed. It was also verified whether the amount of inoculum delivered onto tomato flowers by bumblebees was comparable to that delivered by spray treatments. The first device (SSP-dispenser) consisted of two distinct passageways arranged side by side, one for exiting and one for entering bumblebees; the exit passageway had oblique barriers forcing exiting workers to follow a zig-zag route. The second device (OP-dispenser) had an exit corridor constituted of two tube-like, partially overlapping passageways with a hole in the overlapping sections; to enter the hive, the bumblebees passed through a hole adjacent to the device. The OP-dispenser proved to be the most effective in bee contamination: 100.0% of the captured bumblebees were contaminated, and carried a mean inoculum load of 4.3x10 4 CFU/bee, while only 12.5% of the bees captured at the exit of the SSP-dispenser were contaminated, and carried a mean inoculum load of 1.4x10 2 CFU/bee. Irrespective of the type of dispenser used, in the greenhouses, where the antagonist was transferred onto the flowers by the bees, inoculum density on flowers was always significantly lower than in those treated with the spray. When the OP-dispenser was used, in the greenhouse treated with bumblebees, a significant negative correlation was observed between the inoculum density on flowers of the sample plants and their distance from the hive.