Managing vines organically; growers focus on integrated canopy management techniques.

Most organic winegrowers are focused closely on producing high-quality fruit that will make wines balanced, deeply flavored and expressive of the winegrape variety and place in which the fruit is grown. Organic winegrowers in California use many of the same viticultural practices as conventional

growers. Canopy management practices are critical to vine balance, disease and pest control. Organic winegrowers need to carefully evaluate how pruning, irrigation, fertility, cultivar and rootstock, trellis system and canopy manipulations affect production, vine vigor, wine quality and profitability.

Understanding your site

Vineyard design and variety selection are site specific. If you are going to achieve good economic returns, grow quality fruit and ultimately make good wine, it is important that you carefully match the site's capacity with your choice of rootstock, trellis and variety. Organic winegrowers always start by focusing on the soil, since it controls so many functions of crop growth and quality. If you are planning a new vineyard or seeking to better understand the growth of an existing vineyard, soil physical data can give you great insight as to how the vines are likely to grow:

Vineyard sites with deep soils, high water-holding capacities and moderate fertility are best for white winegrape varieties. These locations are capable of producing moderate to large crops of high-quality fruit. Red cultivars tend to be less successful when planted in these sites, but with devigorating rootstocks, competitive cover crops and careful irrigation, it is possible to grow high-quality fruit.

Controlling excessive vigor is very important to prevent the organic vineyard from having these problems:

* Lush, succulent growth encourages large leafhopper populations that arc not easily controlled with organic pesticides.

* Dense canopies with large leaves, secondary shoots and shading create a poorly ventilated environment and are conditions that favor powdery mildew and Botrytis bunch rot.

* Vigorous shoot expansion during bloom and accumulation of nitrates can cause poor fruit set when flowers shatter during pollination.

* Heavy shade of next year's fruit wood reduces fruitfulness the following year.

Sites such as hillside vineyards with less water-holding capacity, shallower soils and less fertility arc better choices for red cultivars. It is important to note that with irrigated conditions and fertigation (soluble fertilizers), low potential vigor sites can be greatly invigorated when farmed conventionally. Organic growers do not have the same options for inexpensive water-soluble fertilizers.