Isolations from symptomatic grapevines have consistently yielded several fungi including Cladosporium, Penicillium, Alternaria, Rhizopus, Paecilomyces, Aspergillus, Phomopsis, Eutypa, Botryodiplodia, Scytalidium, Phaeoacremonium as well as others. Several of these fungi are known pathogens including Phomopsis, Eutypa, Botryodiplodia, Scytalidium, Cylindrocarpon, and Phaeoacremonium. Symptom expression is well documented for Eutypa and Botryodiplodia. Little is known about the about Phaeoacremonium, Scytalidium, and Cylindrocarpon and the disease symptoms they cause. Pathogenicity tests using grape seedlings and cuttings has shown Phaeoacremonium spp. to be capable of growing in the xylem of grapevines and results in stunting (of both foliage and root system), leaf distortion and discoloration. As of yet no fruit symptoms have resulted from the inoculations but a method for inducing fruit production on young grape cuttings is being utilized in order to obtain fruit symptoms. Pathogenicity test using Scytalidium and Cylindrocarpon have not resulted in symptom expression and plants continue to be monitored. Biology and epidemiology studies of Phaeoacremonium spp. are underway to determine aspects of life cycle and effects of environmental parameters. Vineyards with a history of measles are being surveyed in Santa Barbara, San Luis Obispo, Monterey and El Dorado counties. Vineyards are being monitored several times throughout the year so a disease curve can be developed. The curve will be plotted against environmental conditions (temperature, RH, etc.) in order to correlate incidence of measles with the environment. Severity of the disease is also being determined by rating each vine for foliar and fruit infection and determine crop loss. All weed species and wood cuttings left in the vineyard are being investigated as potential host and inoculum sources and their possible role in the life cycle of Phaeoacremonium. Several types of media are being tested for selectivity to Phaeoacremonium spp. in order to detect inoculum sources in soil and bark. Media are being amended with chemicals such as Benlate, PCNB, and Rose Bengal which inhibit the growth of competing fungi. Disease control is the primary component of this work. Chemicals are being screened against Phaeoacremonium, Scytalidium, and Cylindrocarpon. Benlate and related compounds are effective against Phaeoacremonium.
/wp-content/uploads/2017/09/AFV-Header-Logo.png 0 0 AVF /wp-content/uploads/2017/09/AFV-Header-Logo.png AVF1996-11-10 15:03:282017-11-10 15:04:05Aetiology, Epidemiology and Control of Measles