By clarifying the biology of the European earwig (Forficula auricularia) in vineyards, what new tools and techniques for its sustainable management can be investigated

Background

European earwig is an accidentally-introduced insect present in a range of broadacre and horticultural crops as a pest and in some cases a beneficial insect. It occurs in vineyards across some of Australia’s wine regions including the Great Southern in Western Australia. The earwigs feed on vine leaves in spring with no obvious effects of yield but large populations can be present in the canopy at harvest.

Why is it important?

The pest status of European earwig in Australian vineyards is related to the insect being a contaminant of harvested grapes and adversely affecting the quality of wine. In situations where the earwig is abundant, vignerons may apply an insecticide-based toxic bait for which there is an APVMA minor use permit. Better knowledge of the biology of the insect in vineyards would allow application to be timed so that it is most effective. Although limited information suggests late winter is the primary time of breeding for European earwig in Australian vineyards, little is known of the detail of its life cycle.

The insecticide, which forms the toxic component of the bait for European earwig, is currently under review by APVMA. Alternative insecticides or management options may be required in future.

What would success look like?

Monitoring the abundance of the life stages of European earwig in vineyards would clarify the seasonal cycle of the insect. This would form the basis for recommending the most appropriate time of application of a bait and form the basis for an impetus to review more sustainable means of crop protection.

For further information and to develop an application please contact:

Richard Fennessy: [email protected]

By clarifying the biology of the garden snail (Cornu aspersum) and small pointed snail (Prietocella barbara), what new tools and techniques for their sustainable management can be investigated

Background

Garden snail and small pointed snail are accidentally introduced molluscs present in a range of broadacre and horticultural crops as pests. They occur in Australian vineyards in most regions. Garden snail is more widespread and feeds on the young plant parts of emerging shoots. Large populations of small pointed snail as well as garden snail can be present in the canopy at harvest.

Why is it important?

The pest status of garden snail in Australian vineyards is related to the damage caused to newly emerging shoots affecting plant growth and yield. The pest status of small pointed snail and to a lesser extent garden snail, is related to their presence as a contaminant of harvested grapes adversely affecting wine quality. In such situations to reduce the abundance of these molluscs, vignerons may apply a molluscicide-based toxic bait for which there are APVMA registered products. The effectiveness of the baits may be improved with better knowledge of the biology of the snails in vineyards so that the most efficient timing of the application of baits is undertaken.

Mollusc baits have the reputation of providing poor control of small pointed snail. Alternative approaches to its management are required.

What would success look like?

In Mediterranean climate regions, autumn is considered the main breeding time for both species of snails, but little is known of the detail of their life cycles.

Monitoring the abundance of the life stages of garden snail and small pointed snail in vineyards would clarify their seasonal cycles. This would form the basis for recommending the most appropriate time of application of a bait and form the basis for an impetus to review more sustainable means of crop protection.

For further information and to develop an application please contact:

Richard Fennessy: [email protected]

 

 

What does the effect of early frosts have on vine productivity

Background

Frosts are a continuing problem in the Limestone Coast (LSC) and unpredictability around their occurrence, along with uncertainty about how conditions impact vine productivity, is a source of frustration for many viticulturists. In 2019 the region experienced a -4.5˚C September morning, which was before bud burst in many regions, but may partly account for the poor yields predicted for the 2020 vintage. Extreme events are forecast to become more common with the advent of climate change and uncertainty remains around the impact of frost in terms of severity and longevity relative to growth stage. Regional understanding of (katabatic) wind flow (used to assess frost fan locations) requires modelling beyond anecdotal observation, given the significant investment decisions based on this information.  Forecasting of overnight wind speed has also been linked to poor forecasting of frost events across the LSC region and needs to be better understood.

Why is it important?

Frosts have the potential to reduce grape yields which can result in lower profits for growers. The effect can persist longer term if a frost event is severe enough. Additionally, frosts do not traditionally wipe out entire blocks, instead tending to focus on the lower-lying areas which in turn makes them harder to manage for the remainder of the season. This can have a qualitative effect, with uneven ripening and increased disease risk if not managed accordingly.

What would success look like?

Understanding what a developing bud does when affected by frost and assessing the impact of not only freezing, but close-to-freezing temperatures on fruit set

Determining the differences between tissue temperature vs air temperature to assist vineyard managers better understand when they need to enact frost protection systems

Undertaking modelling to better understand the impact of wind drift and if it is consistent across the region. This could benefit placement of future mitigation techniques and prediction of where damage is most likely to occur in new vineyard developments

Gaining a clear understanding of the ‘new normal’ in terms of frequency of frosts, their potential severity and timing during the year for the LSC wine sector. This could utilise current data being collected for the region through the S-E NRM Board which has obtained funding to look at climate variability across the region.

For further information and to develop an application please contact:

Ulrich Grey-Smith [email protected]

 

Are Boron levels in sandy soils adequate to ensure reliable fruit set and would the application of Boron have a beneficial effect?

Background

Boron is important for successful fruit set. The concentration of boron in some crops grown in the Riverland has previously been shown to be marginal. These crops have shown a positive response to the application of foliar boron at flowering, typically in the form of boric acid.

The concentration of boron in Riverland soils has been assumed to be adequate for the production of winegrapes. However, given the sandy texture of many Riverland soils, it is possible that much of the boron has been leached beyond the rootzone of the vine. These vines may therefore be deficient in boron and respond to foliar sprays of boric acid at flowering.

Why is it important?

If the hypothesis is true, then fruit set in winegrapes grown in the Riverland may be significantly enhanced by the application of boron at, or prior to cap fall, resulting in improved yields.

What would success look like?

The effective fertilisation in grapevines, especially in sandy soils, would be improved and thus provide a better and more even and reliable fruit set resulting in improved and consistent yields.

In the longer term, an increase in boron status of the vine should also improve cane growth and quality.

For further information and to develop an application please contact:

Chris Bennett: [email protected]

How do Cabernet Sauvignon and Malbec vines respond to heat events

Background

Malbec is a winegrape variety notorious for variable fruit set and, in Langhorne Creek, bunch collapse after heat events often occurs, which can reduce yield even further. Likewise, Cabernet Sauvignon appears to exhibit bunch necrosis after sudden, transient heat events, even though the vine canopy appears relatively robust.

Extreme weather events are likely to increase in frequency under a changing climate, and heatwaves within otherwise relatively normal or mild seasons have increased notably in the region over the past five years.

There is some local evidence that simply saturating the root zone with irrigation to mitigate heat impacts is not the solution. Growers who have had success with managing Malbec through high heat have employed overhead low-emission sprinkler or mister infrastructure with an aim to maintain canopy temperatures below 36 degrees Celsius.

There is a desire to understand the physiological factors which contribute to these impacts, hopefully leading to means of better managing vines through heat events.

Why is it important?

Malbec is an important high value niche variety in Langhorne Creek, but its unreliable nature is making it unviable for many to continue growing. In vintage 2019 Malbec represented 2% of the region’s crush and value from an equal percentage of the total vineyard area of the GI (SA Wine Grape Crush Survey 2019). There is demand for the fruit, however growers are increasingly facing hard business decisions around continuing to grow Malbec or remove/rework blocks.

Cabernet Sauvignon (alongside Shiraz) is one of the mainstays of the region. It represents 30% of the total vineyard area of the GI, and equally approximately 30% of the volume and value of the annual crush in a regular year (SA Wine Grape Crush Survey 2019). However, Cabernet Sauvignon is now not considered the no-fuss, reliable producer it once was in the region.

What would success look like?

Strategies, benefits, and limitations for best practice management of Merlot and Cabernet Sauvignon during extreme heat events in Langhorne Creek.

For further information and to develop an application please contact:

Lian Jaensch: [email protected]