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In an attempt to determine the aetiology of young vine decline in Portugal a study was carried out in rootstock nurseries and in young vineyards during the last few years. Rootstock nurseries located in the most important production areas of Portugal (Ribatejo-Oeste and Beira Litoral) were surveyed. The fungi most frequently isolated from discoloured wood at the base of the stem were Cylindrocarpon destructans and Phaeoacremonium spp., although Acremonium sp., Phomopsis sp., Fusarium spp., Fusicoccum sp., Gliocladium sp., Phoma sp. and Sphaeropsis sp. were also present. Young vines (2- to 8-year-old) showing decline symptoms were collected from various vine-growing regions of Portugal. Disease incidence was variable but decline symptoms were present in several wine and table grapevine cultivars grafted onto different rootstocks (99R, 110R, 1103P, 101-14, 140Ru, 5BB and 161-49). Isolations from symptomatic internal tissues revealed that also C. destructans and P. chlamydopsporum were the predominant fungi isolated from the basal end of the rootstocks and grafting tissues. In the pathogenicity tests carried out with C. destructans isolates, the pathogen was reisolated from inoculated plants showing black-foot symptoms, but never from the controls. Our results point out that both C. destructans and P. chlamydosporum might be involved with young grapevine decline in Portugal [Nel tentativo di determinare l'eziologia del deperimento delle viti giovani in Portogallo, di recente e' stato condotto uno studio in vivai per portinnesti e in vigneti giovani. Sono stati monitorati i vivai per portinnesti situati nelle aree viticole piu' importanti del Portogallo (Ribatejo-Oeste e Beira Litoral). I funghi isolati piu' frequentemente dal legno scolorito alla base del fusto erano Cylindrocarpon destructans e Phaeoacremonium spp., sebbene si sia riscontrata anche la presenza di Acremonium sp., Phomopsis sp., Fusarium spp., Fusicoccum sp., Gliocladium sp., Phoma sp. e Sphaeropsis sp. Da diverse zone viticole del Portogallo sono state raccolte piante giovani (da 6 a 8 anni) che presentavano sintomi di deperimento. L'incidenza della malattia variava, ma i sintomi erano presenti in numerosi vitigni da tavola e da vino innestati su portinnesti diversi (99R, 110R, 1103P, 101-14, 140Ru, 5BB e 161-49). Gli isolamenti dai tessuti sintomatici interni hanno evidenziato che C. destructans e P. chlamydopsporum erano pure i funghi predominanti fra quelli isolati nell'estremita' basale del portinnesto e nei tessuti d'innesto. Nei test di patogenicita' effettuati con isolati di C. destructans, il patogeno e' stato reisolato da piante inoculate con sintomi di piede nero, ma mai dai controlli. I nostri risultati evidenziano che tanto C. destructans quanto P. chlamydosporum sarebbero coinvolti nel deperimento delle viti giovani in Portogallo]

Over the last few years research on esca has led to considerable progress in our understanding of the aetiology, epidemiology and physiology of the disease and revealed its complexity. On the basis of the available information, esca can be considered: 1. a disease complex, in the sense that several interacting factors and microorganisms concur to produce the overall syndrome; 2. a complex of at least two distinct diseases: 'white rot' caused by Fomitiporia punctata or other wood-rotting fungi, and brown wood-streaking and gummosis, caused by one or more species of Phaeoacremonium infecting the woody tissue; 3. a real hadromycosis induced by one or more species of Phaeoacremonium or related genera, which in mature or old grapevines is further complicated by the white rot caused by F. punctata. Research has also shown that different syndromes are produced depending on the origin of the infections, the prevalence of the associated fungi and the order in which they become active, and environmental factors. Five syndromes can be distinguished: 1. \"brown wood streaking\" (Petri, 1912). This affects rooted cuttings, rootstocks, and grafted or mother plants and is caused by species of Phaeoacremonium or related genera, often without external symptoms; 2. \"Petri grapevine decline\". This name has been proposed to designate a decline of young grapevines known under various local names ('black goo', 'slow dieback', 'Phaeoacremonium grapevine decline'), which occurs when propagation material or young grapevines are infected, again by species of Phaeoacremonium or related genera; 3. \"young esca\". This syndrome, which Petri thought would evolve in 'esca proper', is characterised by black or brown wood-streaking and xylem gummosis in actively growing grapevines, with or without external symptoms. It is also caused by species of Phaeoacremonium or related genera, like the brown wood-streaking of point 1 above; 4. \"white rot\". When infection is through wounds and solely or mainly by F. punctata or other wood-rotting basidiomycetes, it is characterised by wood rot, which may or may not be accompanied by external (leaf and fruit) symptoms; 5. \"esca proper\". This occurs when white rot develops in the trunks of mature or old vines together with, or after, the development of brown wood-streaking. This, the full-fledged esca syndrome, is caused by the combined or successive action of one or more species of Phaeoacremonium, occasionally accompanied by other fungi, and F. punctata.

The incidence of esca in 5 vineyards (SCFI, GTFI, CBSI-1, 2, 3) in Tuscany was monitored from 1992 to 1994 in SCFI, from 1993 to 1998 in GTFI, and from 1995 to 1998 in CBSI-1, 2 and 3. Disease incidence varied from vineyard to vineyard and from year to year. SCFI was the vineyard most affected with an incidence of 63% in 1993, 20% in 1994 and 46% in 1992. However, symptom expression in individual plants was characterised by very marked discontinuity from year to year. As a result, only 8% of diseased plants in SCFI had foliar symptoms in all 3 years of the survey period. The percentage of consistently diseased plants went down to less than 1% in GTFI e CBSI-3 and was nil in CBSI-1 and 2. The cumulative disease incidence, calculated by counting all the plants that showed foliar symptoms at least once in the years surveyed, was 82, 50, 19, 12 and 10% in SCFI, GTFI, CBSI-3, 1 and 2 respectively. An examination of rainfall and air temperature parameters in relation to esca incidence did not detect any weather conditions especially conducive to esca. However, it seemed that a fresh, rainy summer is more favourable to the chronic form of esca, while a hot, dry summer is more conductive to the acute form [L'incidenza del mal dell'esca e' stata monitorata in 5 vigneti (SCFI, GTFI, CBSI-1, 2, 3) in Toscana, dal 1992 al 1994 in SCFI, dal 1993 al 1998 in GTFI e dal 1995 al 1998 in CBSI-1, 2 e 3. L'incidenza della malattia variava da vigneto a vigneto e da anno ad anno. SCFI e' stato il vigneto maggiormente colpito con un'incidenza del 63% nel 1993, 20% nel 1994 e 46% nel 1992. Comunque, l'espressione dei sintomi nelle singole piante era marcatamente discontinua da anno ad anno. Piu' precisamente, solo l'8% delle piante ammalate in SCFI ha presentato sintomi fogliari nel corso di tutti 3 gli anni del periodo di indagine. La percentuale di piante sensibilmente affette scendeva a meno dell'1% in GTFI e CBSI-3 ed era nulla in CBSI-1 e 2. L'incidenza cumulativa della malattia, calcolata contando tutte le piante che presentavano sintomi fogliari almeno una volta negli anni in cui e' stata effettuata l'indagine, e' risultata pari a 82, 50, 19, 12 e 10% in SCFI, GTFI, CBSI-3, 1 e 2 rispettivamente. Un esame dei parametri relativi alla temperatura e alla piovosita' in relazione all'incidenza del mal dell'esca non ha consentito di identificare condizioni del tempo particolarmente favorevoli al mal dell'esca. Comunque, e' parso che un'estate fresca e piovosa sia piu' favorevole alla forma cronica, mentre un'estate calda e secca sarebbe maggiormente favorevole alla forma acuta]

Young esca was monitored on 3 to 7-year-old grapevines in two vineyards in the Riverland region of Australia over two seasons (1999-2000 and 2000-2001). The affected cultivars were own-rooted Shiraz, own-rooted Cabernet Sauvignon and Merlot grafted onto Kober 5BB. Some of the Cabernet Sauvignon vines began to show symptoms as young as two-years-old. Phaeomoniella chlamydospora was the only esca-associated fungus consistently isolated from symptomatic vines, suggesting that P. chlamydospora alone is responsible for esca symptoms. Spatial analysis was unable to reveal any consistent pattern of symptom distribution [E' stato studiato il mal dell'esca delle viti giovani su viti dell'eta' di 3-7 anni in due vigneti della regione di Riverland in Australia, nel corso di due stagioni (1999-2000 e 2000-2001). I vitigni interessati erano Shiraz autoradicato, Cabernet Sauvignon autoradicato e Merlot innestato su Kober 5BB. Alcune delle viti di Cabernet Sauvignon cominciavano a presentare sintomi sin dall'eta' di due anni. Phaeomoniella chlamydospora era l'unico fungo associato al mal dell'esca isolato consistentemente da viti sintomatiche, facendo ritenere che P. chlamydospora da sola sia responsabile dei sintomi del mal dell'esca. L'analisi spaziale non ha consentito di evidenziare alcun andamento coerente della distribuzione dei sintomi]

In the period 1998-2001, significant numbers of vine samples of different varieties, grafted onto different rootstocks, ready for outplanting or planted and declined a few months or years later, were collected or sent to our laboratory to investigate the presence of phytopathogenic fungi. Three hundred eighty rooted cuttings ready for outplanting, 1,250 young vines planted and exhibiting decline symptoms in the first year of establishment, 82 vines two to nine year old and 27 year old vines exhibiting the classical esca symptoms were examined. Isolations yielded the fungi Phaeomoniella chlamydospora, Fomitiporia punctata and Stereum hirsutum, as well as other fungi of the genera Phaeoacreminium, Cylindrocarpon and Botryosphaeria. The low incidence of these fungi isolated in a low percentage of samples suggested that they could not by themselves be the cause of young grapevine decline. Abiotic causes, such as lesions from improperly healed rootstock disbudding sites and graft unions made in the nursery, as well as improper storage and transportation conditions of the propagated material must also have played a role and made the decline more acute. The occurrence of the isolated fungi as endophytes and their role in the outbreak of grapevine decline remain to be investigated

Twenty healthy cuttings each were inoculated artificially with Phaeomoniella chlamydospora Phaeoacremonium inflatipes and Phaeoacremonium aleophilum. After the formation of callus, they were planted in pots. Approximately one year after inoculation, disease occurrence was recorded as the length of brown vascular streaking from the base of plant toward the shoot tip. Discolored areas were cultured on potato dextrose agar amended with tetracycline hydrochloride (PDA-tet) and pathogens were re-isolated. Inoculation with Pa. chlamydospora showed that rootstocks 3309, 420A, 110R, 5C, Schwarzmann, St. George, and Salt Creek were least susceptible, while 99R, 39-16, Freedom, Riparia Gloire, 140Ru, 16-16 and 1103 were most susceptible. When inoculated with Pm. inflatipes, 16-16,3309, AXR1, Salt Creek, 110R, 5C, Freedom and 140Ru were least susceptible, while 420A, St. George, 161-49, and Harmony were most susceptible. Inoculation with Pm. aleophilum showed that 1103, 420A, Harmony, and Salt Creek were least susceptible, while 110R, SO4, 39-16 and 161-49 were most susceptible. The susceptibility of the rootstocks and the occurrence of vine decline in the field in California did not appear to be well correlated because 3309, 101-14, 5C, and 110R were always most susceptible. But these rootstocks are the most widely planted, and hence the natural occurrence of the disease is probably skewed towards these rootstocks. However, since no resistance was detected in our study, even though there was a wide range of susceptibility, the degree of rootstock susceptibility may not be such an important factor in disease expression under natural conditions.

The growth-stimulating attributes of Trichoderma treatments (dips, soil amendments and drenches with Trichoderma products containing propagules of selected strains of Trichoderma harzianum) in grapevine nurseries, and their effect on the occurrence of fungi in roots and rootstocks of nursery grapevines, in particular fungi causing Petri disease (Phaeomoniella chlamydospora and Phaeoacremonium spp.) and black foot rot (Cylindrocarpon spp.), were compared with quintozene/procymidone treated (standard) vines. Early shoot growth of Trichoderma treated vines was visibly better than that of the control vines. Eight months after planting, at uprooting, percentage take and shoot mass of Trichoderma and standard treated vines were similar, but total root mass was significantly higher for Trichoderma treated vines. Low percentages of Cylindrocarpon spp. were isolated from the rootstocks of treated and untreated vines, while less Petri disease fungi were isolated from rootstocks oí Trichoderma treated vines. Markedly fewer fungi were also isolated from the roots oí Trichoderma treated vines. Incidences of Petri disease fungi in roots oiTrichoderma and standard treated vines were similar, but fewer Cylindrocarpon spp. were isolated from Trichoderma treated vines. These results indicate the potential oiTrichoderma treatments in grapevine nurseries for the production of stronger vines with lower PhaeomoniellalPhaeoacremonium and Cylindrocarpon infection levels.

One vineyard at Castelnuovo Berardenga, in the province of Siena (Italy), was surveyed from 1995 to 1999 to determine the incidence of esca. The vineyard had been established in 1982 using various cultivars (17) and rootstocks (6). In July and September of each year 19 columns, comprising 44% on the total number of vines, were inspected for esca and symptom severity of diseased vines was recorded. At the end of the survey period, maps showing the cumulative incidence of esca were drawn and the incidence for each cultivar and for each cultivar/rootstock combination was calculated. Data expressed on a binomial scale were analysed with the chi sup (2) goodness of fit test. Esca incidence differed significantly among cultivars (P0.001). The statistical analysis showed that the 17 vine cultivars fell into 4 groups with varying susceptibility to esca. The most susceptible cultivar was Semillon, the least susceptible one was Roussanne. A possible indirect role of the rootstock in determining cultivar susceptibility to esca also emerged from the surveys [Dal 1995 al 1999 sono state effettuate indagini su un vigneto situato a Castelnuovo Berardenga, in provincia di Siena (Italia), per determinare l'incidenza del mal dell'esca. Il vigneto era stato impiantato nel 1982 utilizzando vari vitigni (17) e portinnesti (6). In luglio e settembre di ogni anno sono state effettuate osservazioni relative al mal dell'esca e alla gravita' dei sintomi presentati dalle piante colpite su 19 filari, comprendenti il 44% del numero totale delle viti. Alla fine del periodo di osservazione, sono state ricavate mappe evidenzianti l'incidenza cumulativa del mal dell'esca ed e' stata calcolata l'incidenza per ogni vitigno e per ogni combinazione vitigno/portinnesto. I dati espressi su scala binomiale sono stati analizzati con il test del chi sup (2). L'incidenza del mal dell'esca differiva notevolmente fra i diversi vitigni (P0,001). L'analisi statistica ha messo in evidenza che i 17 vitigni erano attribuibili a 4 gruppi caratterizzati da diversa suscettibilita' al mal dell'esca. La cultivar piu' sensibile era Semillon, la meno sensibile Roussanne. Dalle indagini e' pure emerso un possibile ruolo indiretto del portinnesto nel determinare la suscettibilita' della cultivar]

The isolates of Cylindrocarpon destructans used in the present study were selected from a collection of isolates from nursery rootstocks and grapevines showing symptoms of decline in Portugal during the last few years. These isolates were compared on the basis of gross cultural morphology, micromorphology and pathogenicity. The most variable parameter was colony colour. Analysis of micro- and macroconidial size of cultures on \"Spezialler Nahrstoffarmer Agar\" plus 0.1% yeast extract medium (SNAY) revealed that all isolates , except one, cold be clustered in a single group. On carnation leaf agar (CLA) medium, however, all isolates clustered in a single group. All C. destructans isolates were pathogenic on rooted grapevine cuttings of cv Periquita under greenhouse conditions. Internal black-foot symptoms were seen in inoculated plants and the pathogen was reisolated from 60 to 100% of these plants. All C. destructans isolates caused a significant (P = 0.05) decrease in the height of inoculated plants and the majority also caused a significant (P = 0.05) reduction in the number of roots [Gli isolati di Cylindrocarpon destructans utilizzati nel presente studio sono stati selezionati da una collezione di isolati prelevati negli ultimi anni da portinnesti in vivaio e da piante di vite presentanti sintomi di deperimento in Portogallo. Questi isolati sono stati confrontati sulla base della morfologia macroscopica, della micromorfologia e della patogenicita'. Il parametro piu' variabile era il colore delle colonie. L'analisi delle dimensioni dei microconidi e dei macroconidi delle colture realizzate su \"Spezialler Nahrstoffarmer Agar\" piu' lo 0,1% di estratto di lievito ha messo in luce che tutti gli isolati, salvo uno, possono essere inseriti in un singolo gruppo. Su substrato carnation leaf agar (CLA), comunque, tutti gli isolati erano inseribili in un singolo gruppo. Tutti gli isolati di C. destructans erano patogeni su talee radicate di vite della cv Periquita in condizioni di serra. Nelle piante inoculate sono stati riscontrati sintomi interni di piede nero e il patogeno era reisolato dal 60-100% di tali piante. Tutti gli isolati di C. destructans determinavano una diminuzione significativa (P =0,05) dell'altezza delle piante inoculate e la maggior parte causava pure una riduzione significativa (P = 0,05) del numero di radici]

In this work, the in-plant distribution of Plum pox virus (PPV) in seedlings of peach rootstock GF305 and apricot cv Real Fino was studied. Symptom severity and the optical density with the DASI-ELISA test were determined in the leaves. Occurrence of the virus (coat protein and nucleic acid) in the stems and petioles was analyzed by tissue printing of sections. The in-plant distribution of PPV was very irregular in both species, even in severely infected plants. It was also more erratic in seedlings showing an irregular distribution of symptoms, mainly in apricot. A correlation between occurrence of symptoms and localization of coat protein and nucleic acid was also observed. The irregular distribution of the virus, as regards both coat protein and nucleic acid, has negative implications for PPV resistance evaluation, since it renders virus detection and secure inoculation more difficult [In questo lavoro, e' stata studiata la distribuzione in-planta del Virus sharka del susino (PPV) in plantule del portinnesto di pesco GF305 e della cv Real Fino di albicocco. Sulle foglie e' stata valutata la severita' dei sintomi ed e' stata determinata la densita' ottica con il test DASI-ELISA. La presenza del virus (proteina capsidica e acido nucleico) nei fusti e nei piccioli e' stata analizzata mediante stampa dei tessuti delle sezioni. La distribuzione in-planta di PPV era molto irregolare in ambedue le specie, anche in piante gravemente infette. Essa era ancor piu' casuale nelle piante che presentavano una distribuzione irregolare dei sintomi, principalmente nell'albicocco. E' stata pure osservata una correlazione fra il manifestarsi dei sintomi e la localizzazione della proteina capsidica e dell'acido nucleico. La distribuzione irregolare del virus, per quanto riguarda sia la proteina capsidica, sia l'acido nucleico, presenta implicazioni negative per la valutazione della resistenza a PPV, dal momento che rende piu' difficile la diagnosi del virus e l'inoculazione sicura del virus]