Research on pests and diseases of grapevines encompasses a whole-of-system approach with the current focus being pathogen identification, epidemiology and pest & disease management and the impact of diseases on grape and wine composition.
Team leader: Melanie Weckert
Team members: Loothfar Rahman, Kristy Bartrop, Robert Lamont, Nina Pratt
Incorporation into soil of brassica/biofumigation crops and their seed meals causes the release of iso-thiocyanate chemicals which are toxic to soil borne fungi and nematodes. Our previous trials, both in the vineyard and glasshouse, have established that incorporation of mustard plants and its seed meals suppressed parasitic nematodes such as root knot nematode considerably. From these results we are now investigating whether application of brassicas (or their seed meals) under-vine may also be effective in suppressing the incidence of Young Vine Decline associated with pathogenic Ilyonectria spp. (formerly Cylindrocarpon spp.) in Riverina vineyards. Pathogenic Ilyonectria fungi commonly originate from commercial grapevine nurseries, and are a major cause of declining grapevines in the heavy clay soils of the Riverina, especially where planting material is also infected with 'Botryosphaeria' fungi (i.e. 'Bots'). When planting material purchased from grapevine nurseries is infected with both Bots and Ilyonectria, the result is generally either mass grapevine death at planting, or a gradual decline in vine health over the next few years, resulting in greatly reduced vineyard longevity. Biofumigation of nursery soil would benefit grape growers by eliminating the Ilyonectria inoculum, thus allowing the production of non-diseased planting material. Biofumigation may also alleviate the effects of the fungal infection in affected vineyards.
Team Leader: Melanie Weckert and Chris Penfold
Team members: Mark Norton, Tom Nordblom, Andy Whiteley, Robert White, Jennifer Bannister
The under-vine region of the vineyard floor contains the greatest concentration of vine roots, so management of this zone directly impacts vine yield, quality and profitability. Under-vine weed control, whether by herbicides or cultivation, entails considerable costs in terms of machinery and labour, with a present contracted cost of approximately $23/ha per herbicide application. With up to 7 applications and in excess of $100/ha spent on chemicals, the cost of under-vine weed control can be considerable. By contrast, the inputs required in this project are plants – grasses to improve soil structure and legumes to biologically fix atmospheric nitrogen, thus reducing the requirement for artificial nitrogen fertilisers. Our investigation is field based with sites in the Clare Valley, Barossa Valley, Adelaide Plains, Adelaide Hills, Coonawarra, McLaren Vale, Langhorne Creek, Riverland and Riverina. During the growing season, the sites will be monitored for sown plant vs weed populations, biomass and seed production, flowering and senescence timing, gravimetric soil moisture, soil strength and pruning weights. Soil/rhizosphere microbial populations and microbial genes involved in soil nutrient cycles and disease suppression will be evaluated using Next Gen Sequencing.