November in the Tamar Valley, Tasmania

The vines in November are growing rapidly. Having removed suckers that grow form the base of the vines,

you may now be faced with redoing this and thinning shoots in a vigorous year.

With the rain we have had in Tasmania during winter and early Spring 2009. this task is continuous.

Every time I look at my vines I need to remove growth that is unecessary.

November is the month where many decisions need to be made in the vineyard.

It is a time where shoot positioning is of paramount importance for optimum sugar supply to the fruit that will set in December.

With a Scott Henry canopy, I need to give special attention to training my lower cordon to turn down about the last week of November.

I do this by staking out my lower wire to exert pressure on the shoots on the lower cordon.

This holds them out from the vertical position and prevents their developing tendrils from attaching to the wires above and causing them to break off if the wire is turned down too early.

You can expect to lose about 10% of your lower cordon shoots when turning down the Scott Henry system.

You need to judge when the canes have hardened off suffiiciently to keep this loss to a minimum.

It is a most frustrating process but nevetheless you are trying to control the vigour in your vines which at this point in time are hell bent on growing leaf.

Shoot positioning

I put a great deal of effort into ensuring that my canopy is well positioned within my canopy wires.

This ensures that maximum light gets to the canopy that will be responsible for providing sugar to the fruit.

You will need to adjust the wires up to secure the rapidly growing canes and perhaps put on vine clips to stop the wind from pushing all the canes together.

They do better if they all have their own space in which to grow.

Spraying Program

The spraying plan is best worked out theoretically at the start of the season so that you are actively controlling the spread of potential disease in your vineyard depending on weather conditions.

In a cool climate such as Tasmania, the first risk is always from late frost. See the notes from September to minimise damage from this.

As the new growth becomes more vigorous you need to be aware of the conditions which promote the onset and spread of disease such as Downy Mildew.

A period of rain over 24 hours of more than 10 mm at 10 degrees celsius or more provides the conditions for the vines to contract Downy Mildew.

This disease will first be evident in your vines through oil spots on the leaves. This is the primary infection.

Spraying with a copper based spray within 2 days of the oil spots appearing will often prevent the disease from becoming established.

Further rain with continuing temperatures above 10 degrees will cause the primary infection to become established in its secondary phase. This causes severe leaf deterioration and a subsequent loss of fruit quality.

I use Copper oxychloride along with sprays for Powdery Mildew that need to be applied at stages 30cm shoot growth, pre flowering and most importantly 80% capfall. See notes on stages of vine growth to recognise these stages.

Flowering and its implications

The development of the floresence on a grapevine is usually evident from week 3-4 after bud burst.

The florescences ( usually 2 per cane) develop on the first 30cm of the new cane . Their development is critical to your future wine quality.

Grapes are perfect flowers, which means they contain both male and female parts, and are therefore self pollinating under the right conditions.

The male parts of the flower are the stamens, each consisting of a pollen-bearing anther supported by a filament.

Generally there are five anthers arranged around the ovary, but some varieties may have more or less.

Pollen is shed as the anther ripens and is primarily transported by wind, though rarely more than 20 feet (7 metres) from the source.

Pollination occurs when pollen lands on the female parts of a flower.

Each pollen grain grows a long tube towards the eggs within the ovary, and sperm cells move down this tube.

The female parts of the flower consist of the ovary, the stigma, and the style.

The stigma and style provide the entrance to the ovary for pollen.

When a sperm cell in the pollen tube unites with an egg cell in the ovary, an embryo (a new seedling plant) is produced. The embryo grows within the developing seed,

while the entire ovary grows to become the grape berry itself with seeds contained within.

As the ovary is fertilised it is susceptible to many of the diseases that plague the development of the grapes.

It is important that your Powdery Mildew spraying program is on target at this time.

I use Ecocarb at this time providing a barrier from the Powdery Mildew Fungus by changing the pH of the leaf and flower environment making it unsuitable for the fungus to establish.

It also does a good job of killing powdery mildew spores, as long as they are not well established within the growing bunches of grapes.

Monitoring for Insect Pests & Diseases

Light Brown Apple Moth and Vine Moth are active in cool climate areas.

These need to be controlled as each offers a special threat to the developing vines.

Light Brown Apple Moth is evident by silvery scale patches on the leaves or by the hatched grub sheltering in a rolled section of a new leaf.

The growing grubs get into the developing fruit bunches and eat into the young berries usually without observation.

Upon bunch closure, this makes the bunch far more susceptible to Botrytis later in the season when temperatures rise.

 

The Vine Moth is evident through leaf damage and can be killed by hand in a small vineyard.

Choose a time when the sun is shining througn your canopy and you will readily observe the young caterpillars on the underside of the leaves.

Spraying with Dipel every 10 days will control severe outbreaks but I find it more reliable to check daily and to remove the caterpillars when I see them.

 

The vine moth caterpillar

 

Next month:December

Fruit thinning

Estimating bunch numbers

Canopy management

Spraying Program

 

 

This page was last updated on 13/11/2013