ORGANIC GRAPE GROWING

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Organic growing certification may be required to obtain premium prices for organic products. Certification usually requires 3 years documentation of growing that meets the organic certification requirements of the agency. See the web site of the Certified Organic Associations of British Columbia for requirements: http://www.certifiedorganic.bc.ca/

Information on the experience and recommendations of an Okanagan certified organic grape grower (and wine maker) is provided by Hainle vineyards Estate Winery: http://www.hainle.com/hainle-wine/index.html

Many growers chose organic (or “near-organic”) growing without certification for other reasons:

  1. To maintain long-term health and productivity of the soil and surroundings, through a growing environment that is as close as possible to a balanced natural ecosystem (responsible farm stewardship for the future).
  2. To produce a product that has no potential harmful residua from chemical pesticides and herbicides, and that thus is likely to provide a healthy food.
  3. To avoid the potential hazards to the health of the grower of chemical pesticides and herbicides.

Usually organic growing is interpreted to include:

1. No use of chemical pesticides for disease control.

  • usually sulphur (e.g., for Powdery Mildew control) is considered organic, along with a relatively few other spray materials.
  • a balance is usually sought between pests and disease organisms, and their natural preditors and controls, such that the amount of crop loss is acceptable. Also, an increasing number of natural control pest preditors and disease control organisms are available for application to the vineyard. Vine canopy control (pruning for air movement and sunlight) is important for limiting a number of diseases.

2. No use of chemical herbicides for weed and other vegetation control.

  • weed control must be by hand hoeing or other mechanical cultivation, by mulches, or possibly by flame burning

3. No use of chemical fertilizers.

  • fertility must be maintained by composts, manures (preferably from organically raised animals), mulching cover crops, wood ash, and some food processing waste products. “Organic mix” fertilizers are available from some suppliers. If needed, lime is usually provided by ground natural limestone.

4. No posts or other wood products that have been chemically treated (preservatives) may be used in the vineyard. Usually steel trellis posts are used.

  • It is important to note that most vinifera grapes (i.e., classic European wine grapes and their crosses) are poorly adapted to North American diseases and pests. Thus, organic growers may wish to consider European – N. American hybrids that have greater disease resistance, recognizing that these grapes usually have lower market value. However, many hybrids produce excellent wine (so don’t be put off by vinifera snobbery!), and the premium price for organically grown products may offset this disadvantage. On the positive side, the S. Vancouver Island dry summer climate gives a substantial organic growing advantage over eastern North America which has wet humid summers and thus many more disease pressures. Finally, healthy plants usually have maximum disease resistance, so every effort should be made to maintain healthy growing conditions. (RDH, Feb. 2002).

For organic weed control see web site: http://anrcatalog.ucdavis.edu/pdf/7250.pdf

Weed Control for Organic Growers

Weed control in the vineyard can be a daunting task whether you are an organic or conventional grower. One encouraging control method is through the use of a straw or hay mulch. You simply lay a minimum of 6 inches of straw or hay along the rows. The additional benefits are significant. The mulch conserves moisture by reducing evaporation. Soil temperature is better maintained and organic material is added to rhe soil on breakdown. Weed germination is greatly impeded and growth dimished. Couch and other grasses will survive the mulching but are shallow rooted and can be easily pulled out. Partially rotted straw or hay which is not otherwise of use can be utilized but must come from fields which have not used pesticides or chemical fertilizers. This type of product is generally available in this area (S. Vancouver Island). Weed control by straw or hay mulching is not the only organic option but may be worth considering (from E.P).

Posts for Organic Growers

Treated wooden posts cannot be used by growers wanting to be certified “Organic”. These posts have been pressure treated with three compounds to resist rotting; arsenic, chromium and copper (CCA). These substances can leach into the soil. The rate and extent of leaching depends upon the local climate, acidity of the rain and soil, age of the wood and how much of the compound was applied. The United states Environmental Agency (EPA) has conducted many studies, especially in the last decade. On February 12, 2002 the EPA announced a voluntary decision by the industry to move treated lumber products away from the public by December 31, 2003 after which CCA will no longer be used to treat wood for most residential settings (a recent report on radio indicated the main concern was where people¹s skin would often come into direct contact with the wood, as for example on decks….Ed).

The alternatives are untreated posts with a sealer stain, cedar posts, cement, plastic and/or metal posts. Wooden posts will have a limited life span and will likely need to be replaced before the grape plants. Plastic and cement posts will be expensive. Used, 1 1/4 inch or larger, thickwall, steel pipe is usually available from junk dealers at a cost of $9-$12 per 9 foot length. For best results the end-posts need to be set in cement and braced. Holes will need to be drilled to hold the wire on which the grape plants will be secured. Iron T-Post stakes are available in 9 and 10 foot lengths from a number of suppliers. Integrity Sales on Keating X. Rd. has them at $7.75 and $8.45 respectively (less a VIGGA discount of 5%). Wire can be hung on these without drilling but they all may need to be sunk in concrete and end-braced to remain solidly in the ground. These are extensively used in the Napa Valley. The various post dealers in this area have a wide range of prices for post products so it is adviseable to do some shopping.
from E.P.