Rust Mite Spray Timings

Rust Mite levels were seen to be significant in some vineyards last season. Rust mite are microscopic mites that enter into grapevine buds during early spring and affect the growth of early season shoots.

The significant level of Rust Mite’s last spring has made us re-think our recommendation regarding Rust Mite control. It is likely that a high percentage of vineyards monitored last season will benefit from a controlling sulphur spray.

We have been advising our clients regarding whether they should apply a controlling sulphur spray, or not for this season. If you would like specific advise please contact DJ’s.

Recommendations for prevention of Rust Mite symptoms are:

When Rust Mite symptoms in spring are stunted & uneven shoot growth.

• Application of wettable sulphur @ 500g/100lt (include non ionic wetter at label rate if not adding oil).

• Water rates of 600 – 900 lt of water per hectare - do not use less than 500 lt/ha - increased water rate should be used if worried about coverage.

• Make sure coverage of the cordon and all spur wood is thorough.

• Inclusion of Canola oil or Mineral oil at 2% (2lt per 100 lt) may improve control (10-15%) but should only be applied if the variety being sprayed is fully dormant (eg. Cabernet). Need to be aware that some Canola oils may contain GMO’s.

• A period of 2-3 fine days and 15 degrees C or higher on the day of spraying is ideal.

• Chardonnay is the indicator variety for timing of spraying in each region. Spraying should be done on all varieties when Chardonnay reaches 10% green tip (ie most buds woolly bud). Look for services like McLaren Vale CropWatch to advise of this timing.

McLaren Vale - Valley Floor.

Our feelings are that spraying should occur from the last week of August to the end of the second week of September on all varieties/blocks that require rust mite treatment.


Currency Creek & Langhorne Creek.
Spraying should occur from the last week of August to the end of the second week of September on all varieties/blocks that require rust mite treatment.

Blewitt Springs & Clarendon.

Spraying should occur from the first week of September to the end of the third week of September on all varieties/blocks that require rust mite treatment.

Adelaide Hills.

Mid-September through to the end of September. To get ideal timing find a block of Chardonnay in within your mesoclimate for exact timing.

Rust Mite symptoms in spring, cv. Cabernet Sauvignon, Blewitt Springs McLaren Vale GI. 

Bud Dissection Q&A

Hi, 

I am curious about looking at grapevine buds under the microscope. Could you also please let me know how many buds you can dissect in an hour, as I have a uni project to do on yield analysis and the number would be of assistance.

Many thanks, Andrew

Dear Andrew,

Almost anyone can learn to dissect buds, but not everyone has the patience to sit down and complete many samples. We use a compound microscope with to eye lenses that give a stereoscopic view of the inside of the bud.  This allows us to assess the internal bud structure and look at the inflorescence primordia which are the structures that develop into grapevine flowers.

Bud Dissection.

We would average two to three buds a minute, therefore it takes us between one and one and half hours to complete a vineyard (30x; 5x bud canes).  We would generally limit ourselves to three vineyards per day to keep our eyes fresh.

 

The time it takes to dissect buds under a microscope varies from variety to variety. Sauvignon Blanc has small buds and small inflorescences which make it the slowest variety to assess. Grenache has large buds and large inflorescences which are the quickest to assess.

Low bud fruitfulness and high primary bud necrosis is linked to vigourous vineyards.

 

Internal bud structure.

We perform dissections to look for low fruitfulness and assess the level of primary bud necrosis.

If we find problems with fruitfulness eg. levels below 1 bunch per bud (inflorescence primordia per bud), or high levels of bud death from primary bud necrosis, we advise growers to change their pruning in the short term and look at their management in the long term.

It is when you find blocks like these bud dissections come into their own as a vineyard tool.

DJ's agronomist Matthew Wilson says,  

"Vineyards with high levels of lateral shoot growth can show low levels of fruitfulness. Primary bud necrosis is often common in vigorous vines and this is contributing to low fruitfulness. If you can catch this before pruning you can take action to prevent correspondingly low yields at harvest."

Primary Bud Necrosis (PBN) note how the centre bud has died but the two secondary buds are viable. This would indicate that secondary buds will burst in place of the larger primary bud.

For more information refer to bud dissection and primary bud necrosis.

Assessing Vineyard Canopies

James Hook shows Assessment of Vineyard Performance cv. Shiraz to predict grape quality. 

Vintage 2017 Summary

2017 Vintage seasonal summary with James Hook.

Vineyard Update: Grapevine fungal diseases in 2016/17

James Hook on fungal disease identification. Vintage 2017. 

Downy Mildew explained in less than 5 minutes.

James Hook explains a Downy Mildew Primary Event 10:10:24 event in laypersons terms.

Grenache Renovation Project.

Ask James or Derek for more information about old vineyard regeneration. 

Organic based farming: Future proof

Does McLaren Vale have an Organic Future?
Could the McLaren Vale region be one big sustainable food basket?

James Hook argues the answer has to be yes.

If McLaren Vale has a future as a farming region it must embrace sustainable farming. It needs to produce products that attract premium prices to be financially sustainable. It needs to act as a steward for the region and protect the area from the perils of urbanization. The widespread adoption sustainable, high quality farming taking the best from organic and/or biodynamic techniques will maintain the vitality of the region and give McLaren Vale producers a sustained competitive advantage in their winemaking. This will allow higher prices for grapes which increases the value of the land, which decreases the pressure to put in housing.

I feel the way to do this is to adopt sustainable farming as a code of practice for the whole district, as an industry and as a community to challenge ourselves and reap the benefits.

Reduced demand, lower wine grape prices and diminishing profit margins mean production of high quality fruit in McLaren Vale has become vital for winegrowers. For ill or good the strength and growth in the wine industry has greatly contributed to the region. The future of the grape growing and winemaking and the future of the area are intertwined. At present there is an oversupply of C grade fruit in the region, fruit that is made into wine in the $10-15 dollar per bottle range. There is high demand for A grade fruit which produces wine above $25 per bottle. It is at these quality levels that the majority of viticultural businesses need to be producing to be profitable. Conventional agriculture has not given us that with much of our fruit falling below the top grades.

What we describe as conventional agriculture is a recent trend. With the appearance of cheap mineral fertilisers and pesticides in the early 1950s, farmers quickly abandoned traditional or organic methods of farming and became heavily dependent on both agrochemicals and labour-saving machinery. Farmers discontinued organic methods not because they did not work but because they could not compete with the new type of agriculture.

Accepted practice viewed organic farming as inefficient. The race was to grow the most, not to grow in the most sustainable way. Grape growers received similar prices whether they grew 5 tonnes to the hectare or 15 tonnes. The emphasis was big is better. In spite of this, organic farming was pioneered because many local growers looked for ways to reduce the amount of fertilisers and pesticides they were using.

Enter the modern concept of sustainable farming. Not a return to the past, rather a marriage of scientific advances with traditional practices.

In the McLaren Vale wine industry, Battle of Bosworth, Rino and Greta Ozzella at Grancari Estate and many others certified their vineyard organic. Unsung growers like the late Modestino Piombo developed a successful vineyard at Sellicks Hill with little more than a dodge plow and wettable sulphur. Recently Paxton viticulture have successfully converted significant amounts of vineyard to BioDynamics, an organic system with soil as the key factor in farming, and sustainability as the goal. The Leask family, Doole vineyards and the Gemtree wines have all converted vineyards to this system.

Following the lead of these pioneers elements of the organic and biodynamic philosophy have been starting catch on with mainstream grape growers.

The pioneers were concerned, above all else, about the soil beneath their feet. Organic and Biodynamic philosophy is centred on practices designed to improve the richness and stability of the soil by restoring its organic matter and avoiding synthetic chemicals.

Not surprisingly this commitment to soil balance also has a flow on effect to wine quality. Many of the characteristics of a well maintained organic or biodynamic vineyard have the same traits of vineyards that achieve A grade results. This is particularly the case with McLaren Vale staples Shiraz and Grenache. They have moderate vigour, develop open canopies, catch a good deal of sunlight, have thicker skins, are not over fertilised and have balanced soil.

McLaren Vale has many advantages that make sustainable wine production a reality. The area has creek lines and roadsides that can be re-vegetated to offset farming energy demands and electrical power can be generated from shed and winery roof space. McLaren Vale’s soils are perfect for farming and we have a ready supply of organic fertilisers from Adelaide’s waste and animal farming nearby.

Currently 40% of the grape growers water needs are filled by reclaimed water from Adelaide with plans ahead to increase this, and the balance of water comes from underground sources which are carefully monitored to make sure are healthy.
Pastures grow well in between our vine rows stopping soil erosion. Mechanical weeding or new plant based herbicides can control weeds where they are not needed.

McLaren Vale has relatively low risk of disease affecting yield and quality. Powdery Mildew is a slow creeping disease that is limited by sunlight. Open canopies that let sunlight into the fruit zone inhibit its growth naturally; these same open canopies have the advantage of suiting A grade red wine production. Organically registered products like sulphur are effective in controlling the disease.

Downy Mildew is a rare occurrence in the district with the last significant outbreak in 1992. Downy Mildew needs wet summers where significant rain occurs in November and December. Wet summers are infrequent. When the next wet summer comes with increased knowledge about the disease, I believe with the correct timing, grape growers can use copper as an emergency measure to limit Downy’s effects and still meet organic requirements. Botrytis is a hit and miss problem. A grade red varieties with tough skins will always fair better than those which are pumped up and weak skinned. Nature is clever like that.

The pioneers have showed the district how. Organic practices use cheap and locally available resources. Vineyards are being successfully farmed avoiding factors over which farmers have little control: mineral fertilisers and synthetic pesticides. The opportunity is here to make the region the centre of sustainable grape growing.

I feel adopting organic practices on a wide scale represents an effective way to reduce the oversupply of C grade fruit and promote more fruit into the A grade. Is organic certification, or whole hearted Biodynamics in its pure form the solution, maybe not? However the concept of widespread semi-organics by adopting organic techniques to increase soil health, decrease the use of unnecessary farm inputs and push towards sustainability is attainable and attractive.

I am not suggesting we change the world, just look at what is happening in the region and see where we fit into it. The scientist in me tells me this is possible. It is all practical and we have made a reasonable start, now is the time to keep striving.

For more information contact james@djsgrowers.com.au