Evaluation of Fungicides for the Management of Botryosphaeria Canker of Grapevines

Abstract

The family Botryosphaeriaceae comprises a number of species that are associated with the dieback disease of grapevine (Vitis vinifera), referred to as Botryosphaeria canker. To date, there are few effective agents available for the management of this disease. In this study, fungicides were evaluated for controlling the disease using a combination of in vitro tests and field trials. Twenty fungicides registered for use on other diseases in Australian viticulture were tested in vitro for their effect on mycelial growth of four species within the Botryosphaeriaceae. The concentrations of fungicide at which 50% of mycelial growth is inhibited (EC50 values) were significantly affected both by fungicide and isolate (P < 0.001). Differences in sensitivities of the four species to the fungicides were negligible (0.41 to 0.59 mg/liter). The most effective fungicides were fludioxonil, carbendazim, fluazinam, tebuconazole, flusilazole, penconazole, procymidone, iprodione, myclobutanil, and pyraclostrobin, for which EC50 values were <1.0 mg/liter. These fungicides were evaluated under field conditions, in addition to the pruning wound protectants Bacseal Super, Garrison, and ATCS tree wound dressing, as well as the biological control agent Vinevax. In field trials, carbendazim (Bavistin), fluazinam (Shirlan), tebuconazole (Folicur), Garrison, and ATCS tree wound dressing applied to freshly cut pruning wounds were the most effective and reduced infection by Diplodia seriata and D. mutila by 41 to 65%. These results suggest that the occurrence of Botryosphaeria canker on grapevines may be reduced via treatment of pruning wounds with selected fungicides as soon as possible after pruning.

Evaluation of DMI fungicides against species of Diplodia and Neofusicoccum associated with Botryosphaeria canker of grapevine

“…seriata, N. australe and N. parvum (Bester and Fourie, 2005;Savocchia et al, 2005;Bester et al, 2007;Auger et al, 2010;Amponsah et al, 2012). Additionally, our results agree with a recently published report (Pitt et al, 2012) indicating that tebuconazole and myclobutanil are very effective at controlling the mycelial growth of D. seriata and N. parvum in vitro.…”

“…Prochloraz and prochloraz plus epoxiconazole also appear to be highly effective against these fungal species of the family Botryosphaeriaceae, which are commonly associated with trunk diseases of grapevines. However, DMI fungicides shown to be highly effective in vitro have occasionally performed poorly in field tests (Sosnowski et al 2008;Pitt, 2012), and it is important to study the effectiveness of these DMI compounds in the vineyard before reaching any final conclusions.…”

Effectiveness of Natural Antifungal Compounds in Controlling Infection by Grapevine Trunk Disease Pathogens through Pruning Wounds

“…Many different studies have been carried out to monitor pruning wound protection with chemical antifungals such as benomyl, carbendazim, fosetyl, tebuconazole, or thiophanate-methyl, among others (7,20,23,25,26,45), to cite only the latest. Some of these chemical fungicides have proven to be effective at different rates in the protection of pruning wounds.…”

Effect of Fungicide Application on the Management of Avocado Branch Canker (Formerly Dothiorella Canker) in California

“…Sitnilarly, treatments comprising fludioxonil inhibited mycelial growth of Botryosphaeria dothidea, Diptodia seriata, Lasiodiplodia theobromae, Neofusicoccum parvtim, N. luteum, and N. australe (1,22,33,35). They included azoxystrobin, fludioxonil, metconazole, propiconazole, and pyraclostrobin.…”

“…Variation among fungicides, fungal pathogens, between trials and time of inoculation, and interactions for internal and external lesion lengths during the field experiment (21). Fludioxonil, myclobutanil, and pyraclostrobin were fungicides with low EC50 values in fungicide evaluation for the management of Botryosphaeria canker of grapevines (33). Similarly, Aluminum tris (-0-ethyl phosphonate), which was considered to be highly effective in controlling trunk canker disease (4,7), was ineffective in our in vitro fungicide screening.…”