Charles Sturt University
Charles Sturt University

Vine Physiology

The vine physiology team at the NWGIC researches factors that impact on berry composition and yield including extreme temperatures, water stress, plant nutrition and carbohydrate partitioning. It is also focused on defining sustainable and efficient vineyard management practises and developing automated systems for yield prediction.

Selected Research Projects

Symptomatic and metabolomic grapevine responses to injuries caused by different herbicides

Team leader: Dr Gerhard Rossouw (NWGIC)

Team members: Dr Bruno Holzapfel (NSW DPI), Dr Suzy Rogiers (NSW DPI), Prof Leigh Schmidtke (NWGIC)

The research will assess the implications of injudicious herbicide exposure on visual grapevine symptoms in conjunction with vine physiological and metabolic responses. Grapevines exhibit major phytotoxicity towards many herbicides that are commonly used against invasive broadleaf and/or grassy weeds in crop production regions. In fact, off-target herbicide drift within diversified cropping regions could have severe repercussions on vine leaf function and crop viability, while potentially causing undesirable residue levels in finished wines.

Most literature on grapevine herbicide injuries described leaf anatomical and some basic physiological implications associated with exposure to certain herbicides. However, the grapevine primary metabolic reactions toward different herbicides remain ambiguous. An initial in depth understanding of the physiological and metabolic alterations, as induced by exposure to problematic herbicides, would supply a foundation to develop management strategies aimed at avoiding or minimising herbicide injury at key stages of the season. The project will assess leaf, fruit and root metabolic responses to vine herbicide drift exposure, and especially the related implications on fruit quantity and composition. A further focus will be to describe the injury symptoms (especially related to foliar and bunch development) associated with different herbicides, and linking these symptoms and the recovery thereof, to primary metabolic responses.

Evaluation and demonstrating of new disease-resistant red and white grapevine selections in a cool and warm wine region in NSW

Team leader:  Dr Bruno Holzapfel (NSW DPI)

Team members: David Foster (NWGIC/DPI), Adrian Englefield (NSW DPI), Darren Fahey (NSW DPI), Dr John Blackman (NWGIC), Stephen Gottschall (NSW DPI)

Powdery and downy mildew infect both the reproductive and vegetative organs, reducing carbohydrate production and berry quality, with negative consequences for overall productivity. As a result, the wine industry has a heavy reliance on chemical fungicides to control and prevent outbreaks of these pathogens in the vineyard. The assessment of new variety selections is not only important to evaluate resistance against pathogen attack, but also to determine how they can handle abiotic stress such as heat events and drought, particularly in the warmer grape growing regions.

Breeding new grapevine cultivars with resistance to fungal pathogens presents an opportunity to substantially reduce the use of plant protection agents in vineyards, and therefore lower production costs and reduce the impact of viticulture on the environment. Resistance can be achieved by crossing suitable parent cultivars, screening for desired disease resistance and other beneficial traits, and then evaluation of superior selections and their wine making potential under field conditions for several years in different regions before release.

Reducing inputs will be a key driver of economic sustainability for the Australian wine industry. This project seeks to evaluate existing powdery and downy mildew resistant varieties that do not require sprays to identify elite individuals suitable to the Riverina and other regions in NSW that have traits that can also assist in reducing inputs in the vineyard. Improving profit by selling at a higher price point is the other key driver for industry economic sustainability.