Friday, September 28, 2012

Grapevine Nutritional Problems - Q&A

Zinc deficiency.

Magnesium deficiency on a white grape cultivar.
If conditions are cold and wet  your vineyard it can have slow growth and all types of soil can show nutritional problems.

Vineyards on light sandy soil are naturally low in topsoil nutrients. The same is also true those with heavy clay soils which can become waterlogged at this time of year thus preventing nutrient uptake.

Magnesium deficiency.
We have attached pictures of the most commonly seen vineyard nutritional disorders - Zinc (Zn), Magnesium (Mg) and Iron (Fe).

Zinc disorder is often called little leaf because it affects shoot growth and grapevine leaf size (top). 
Iron deficiency.
Iron (Fe) deficiency shows up as pale leaves. This is often called lime induced chlorosis. This is due to the alkaline limestone rock underneath locking up iron and grapevines are not able to take iron up. Iron nutritional problems are generally fixed once the weather warms up and vine uptake increases.

Iron deficiency compared to healthy leaf.
Grapevines tend to show Potassium (K) deficiency when they are heavily cropped and maintenance applications of K have not been made in the vineyard. This shows up in mid- to late summer, where leaves may have a bronze color, especially on the west-facing side of the trellis. Some leaves may have dark spots or blotches.

Potassium deficiency.
We hope this sheds some light on the subject. If you have further questions why not take a picture and sent it to us?

Thursday, September 20, 2012

Light Brown Apple Moth - UPDATE 20/9/2012

The first generation of Light Brown Apple Moth has been seen in McLaren Vale. A background level of one Light Brown Apple Moth larvae per twenty vine panels has been detected. As shown below during early vine growth stages larvae hide in the first leaf and curl it over to protect themselves from predators.

Light Brown Apple Moth at Sellicks Hill in Tempranillo.


Monday, September 17, 2012

Green Manure - UPDATE 18/9/2012

Spring time give us a chance to assess soil fertility by observing what is growing in the vineyard. One group of plants we are particularly interested in are called the "green manures." We think these are a great indication that soil organic carbon is improving.

These are the most common green manure plants we found growing on roadsides and in vineyards and orchards this season.
  • Burr Medic – Ben South thinks this is Paragio pasture medic gone wild from paddocks.
  • Snail & Barrel Medic – Escaped pasture grasses similar to Burr Medic but with different seed and different growth habits.
  • Vetch – planted as a soil erosion control agent beginning in the 19Cth continuing to the 1980’s in sand mining operations on California Rd.
  • Clover – Ben has had good success with Balansa clover as a covercrop, plus ‘wild’ white/strawberry/sub clovers have seen growing in old almond orchards replanted to vines near Willunga (both pictured below).

Clover in Willunga.
Balansa clover foreground and burr medic background
Green manure crops are so named because they add nutrients and organic matter to the soil. Green manure crops are also useful for weed control, erosion prevention, and reduction of insect pests and diseases.

In addition to the 'wild' green manure plants (burr, snail, barrel medic, clover and vetch) farmers have actively planted field peas and faba beans. All of these plant types all grow through winter and flourish in spring. They all fix nitrogen from the atmosphere and draw it into the soil.

Vetch -  

Grows well and persists for many seasons. It is able to self-sow. Vetch is growing well across all of McLaren Vale. Vetch seems to do well in wet winters which favour its lifecycle.

Vetch is relatively slow growing in winter but has prolific spring growth. It has been used to stop soil erosion in McLaren Vale for over 100 years. Now a natural population grows in vineyards - picture McLaren Vale.
.

Beans and Peas- 

Beans and peas are generally planted by vineyard owners and orchardists. They are annual crops and don't persist for multiple seasons without resowing.

Field peas are a hardy winter legume that can provide good bulk and help with soil structure.
Picture - Seaview district sandy loam soil.































 

   

Medics - 

Many vineyards have good self-sustaining populations of medic. Wild burr medic is growing across many different soil types.

Burr medic is very common in the McLaren Vale region.
Burr Medic grows on a wide range of soils, but does best in alkaline soils. 
Grows most prolifically on heavy clays like this at Malpas Rd, Willunga.

Clover - 

Many vineyards have good self-sustaining populations of clover - it thrives on alkaline soil.

Sub clover growing in vineyard midrow at Clarendon.
In many areas, particularly on acidic soil, clover is short-lived because of a combination of insect pests, diseases and nutrient balance; this is known as "clover sickness".


DJ’s All-rounder Blend. The all-rounder blend has clover, medic and perennial grasses with the balansa clover dominating (over knee height) in the photos – planted this autumn with SOA and guano.  The grower will let this perennial sward go to seed this year to build the clover and grass seed bank.
In many situations clovers make an excellent seed mix inter-sown with other varieties.Vineyard ryegrass mixes were very popular in the 1990's and early 2000's. Many of these are persisting and the clover has survived to become self-generating.

 

What are you seeing? - 

This winter has been wet and favourable to crop growth. What are you seeing on your farm? Are you concerned about soil carbon and ground cover and if so do you have plans in place for next year? We are always interested to hear what is working for you.

Thursday, September 13, 2012

Elephant Weevil - UPDATE 13/9/2012

Elephant Weevil, Orthorhinus cylindrirostris image credit: kraftypanda
One of the tell tale signs of Elephant Weevils are these large round emergence holes
- http://djsgrowers.blogspot.com.au/2008/10/elephant-weevil.html

Friday, September 7, 2012

Copper Hydroxide Mixing - Q&A




Dear Derek & Team,

We have noticed that we get some copper falling out of our spray solution. We use copper hydroxide mixed. Do we have to pre-mix it?

Peter.


Hi Peter,
The new formulations of Copper Hydroxide like Champ mix very well, but they do need to be mixed in a specific order when tank mixed with other products. Fully mix the copper hydroxide in the spray tank before adding other products.
Please look at the video on mixing. It covers the in and outs of application.

Wednesday, September 5, 2012

McLAREN VALE - SUSTAINABLE WINEGROWING AUSTRALIA VINTAGE 2012

The results for the McLaren Vale sustainability programme are being collated and published. DJ's has been looking through the results gathering information for districts CropWatch programme.

During the 2012 Vintage 87 grape growing members, with 145 vineyards, submitted their operations for assessment by completing the sustainability workbook.
Summary of results
The harvest from their vineyards produced 11,905 tons of grapes. Remarkably this was 37% of all of the grapes harvested in McLaren Vale (the total crush in McLaren Vale was 31,755 tons 1). 

McLaren Vale Sustainable Winegrowing Australia members produced 10,444 tons of red grapes in 2012, 39% of the total red grape harvest. Members produced 1,461 tons of white grapes in 2012, 27% of the total white harvest

The majority of members have been using low input conventional farming techniques, 51% while 8% are biodynamic (certified and uncertified) and 15% organic (certified and uncertified).

The workbook results show some areas where McLaren Vale is progressing well and is a leading example of adapting farm practices to meet economic, social and environmental change. The increased use of reclaimed water for irrigation is an example of the industry adapting. However there are other challenges the sustainability programme has highlighted that the industry will need to face in order to improve.