Proactive control of petri disease and black foot disease in newly established vineyards
Fourie and Halleen (2004) determined the incidence of Petri Disease fungi (Phaeomoniella chlamydospora and Phaeoacremonium spp.) and black foot disease fungi (Cylindrocarpon spp.) in grapevine rootstock mother plants. Isolations from the basal and pruning wound ends of 2-year-old stubs were made from different cultivars, ages and growing areas in South Africa. Phaeoacremonium spp. and Cylindrocarpon spp. occurred at low incidences (average 0.12% and 0.17%, respectively) and Pa. chlamydospora at much higher incidences (up to 21.5%) depending on cultivar and area. Fourie and Halleen (2002) found Pa. chlamydospora and Phaeoacremonium spp. in canes produced from rootstock mother vines although at a low frequency. However these results were obtained by means of isolations. Retief et al. (2005) detected Pa. chlamydospora in 80.9% of samples tested by means of molecular detection compared to 24.1% positive detection by means of traditional isolations, which emphasised the need for more sensitive detection techniques. Furthermore, a study conducted by Halleen et al. (2003) investigated the presence of fungi in grapevines of South African nurseries and found Pa. chlamydospora and Phaeoacremonium spp. to be present in healthy rootstock propagation material. However the incidence of Cylindrocarpon spp. only increased after planting in nurseries. Less than 1% of the plants were infected with Cylindrocarpon spp. prior to planting in nurseries (October), which increased to 50% by end of the nurseries’ season (June). Therefore it can be concluded that most nursery material received for planting contains a low percentage of Petri disease and black foot disease fungi and with stress conditions like drought, poor nutrition and root development, these pathogens can multiply and colonise tissue. Establishment of young vines in itself is a stress condition and in combination with the pathogens it can result in a high percentage of dieback of young vines. The aim of this project is to determine whether treatments could limit further infections and improve the success of newly established young vines.
Halleen, F and Fourie, P H. 2007. Plant health in vine nurseries. Wingerd Kwekersverening. 12 June, Wellington, South Africa.
Halleen, F. 2007. Black foot disease of grapevine. Lecture. University of Stellenbosch. Department of Plant Pathology. 24 August, Stellenbosch, South Africa.
Halleen, F and Fourie, P H. 2007. Black goo: identification and control measures. VinPro and OWK Information Day, 13 September, Upington, South Africa.
Halleen, F and Fourie, P H. 2008. Epidemiology and control of black foot and Petri diseases of grapevine. Lecture. University of Stellenbosch. Department of Plant Pathology. 22 August, Stellenbosch, South Africa.
Halleen, F. 2009. Houtverrottingswamme. Terason Wingerdopleiding, 12 June, Wellington, South Africa.
Halleen, F. 2009. Grapevine trunk disease research. Winetech visit to ARC Infruitec-Nietvoorbij. 18 November, Stellenbosch, South Africa.
Halleen, F, Fourie, P H, Mostert, L, McLeod, A, Van Niekerk, J M, Spies, C, Kotze, C, Mutawila, C and White, C. 2010. Winetech and VinPro Information Day. 4-6 and 11-12 May, Vredendal; Malmesbury; Worcester; Robertson; Stellenbosch, South Africa
Fourie, P H, Halleen, F. 2004. Proactive control of petri disease of grapevine through treatment of propagation material, Plant Disease, v. 88 (p. 1241-1245)