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November 7, 2000


Organic Horticulture Colloquium


Introduction to Organic Horticulture Colloquium 18 Aug 00

Milton E. McGiffen, Jr. and Jeffrey D. Ehlers
Department of Botany and Plant Sciences, University of California,
Riverside, CA 92521-0124.

Jose L. Aguiar
University of California Cooperative Extension, Indio, CA 92201

The Organic Horticulture Colloquium was a well-attended set of talks at
the ASHS meetings in Minneapolis on 30 July 1999. The broad interest in
the topic is evident by the diverse workgroups that served as cosponsors:
Consumer Horticulture and Master Gardeners (CHMG), Marketing and Economics
(MKEC), Mineral Nutrition (MNUT), Vegetable Crops (VCM), and Waste
Utilization in Horticulture (WUH). The papers from the colloquia cover
divergent issues in economics, production, and extension of knowledge.

A diverse group of consumers purchase organic products. Organic food
sales have grown dramatically throughout Europe, Asia, and the Americas
(Thompson 2000). Organic produce is now widely available in major
supermarkets, and has expanded to include most fruits and vegetables.
Organic meat and nursery crops are also increasing in abundance.
Consumption has moved from a small group of activists into the mainstream.
Fresh, frozen, and processed products are now available at most grocers.

Organic farming is sometimes recognized more for the fervor of its
advocates than the products produced. Indeed, the organic movement has
led to real changes in national agricultural policy, including programs to
decrease pesticide residues and increase the sustainability of rural
communities (Miles 2000). Many conventional growers are now farming a
portion of their land as organic or incorporating some of the central
concepts of organic production into otherwise traditional farming systems.
All segments of agricultural industry have scrambled to adapt with new
methodology (Gaskel et al 2000) and training (Creamer 2000).

Many of these changes are evident in California’s Coachella Valley, the
low desert area surrounding Palm Springs. Researchers from the University
of California Cooperative Extension and USDA have been experimenting with
cover crops as a way to maintain soil quality in many cropping situations
(Cavanaugh 1998). But vegetable producers plant two or more high value
crops per year to recover high land and water costs. It seemed
impractical to invest additional land, labor, and other production costs
into the uncertain payback of cover crops.

But growers began to experiment. They found a gap between spring and
fall plantings when the land was usually fallow (Ngouajio and McGiffen
2000). A cowpea cover crop was inexpensive, required little water and no
fertilizer, and produced abundant biomass and nitrogen (Aguiar et al
1998). Cowpea cover-crop acreage went from virtually none in 1997 to over
1,000 hectares in 1999. Some of this increase was driven by the increased
demand for organic produce. Many limited resource farmers view organic
vegetables as a niche market that allows them to remain competitive
(Vischer 1994). Since production costs and market value are generally
higher for organic produce, some growers wondered whether the costs of
growing organically certified produce was worth the benefit (Brumfield et
al 2000). But many farmers also recognized that cover crops offer many
advantages in vegetable production, including N fixation, recycling
nutrients, reducing soil erosion, and adding organic matter to the soil
(Gaskell et al 2000; Stirzaker et al., 1992; Stirzaker et al., 1993).
Strong grower interest led to increased breeding and pest management
research to develop cover crop cultivars with enhanced resistance to
nematodes (Matthews et al 1998), weeds (Hutchinson and McGiffen 2000), and
other pests (Hall et al 1997). Because nematode, weed, and other pest
populations decline after planting resistant cowpeas, it appears possible
that novel cover crop varieties could replace fumigation and other
chemical pest control. Cover crop cultivars may eventually be developed
to solve specific problems from conventional agriculture, such as the loss
of methyl bromide and other pesticides.

Organic horticulture has increased in size and scope to become a vital
component of traditional market and production systems. This colloquium
addresses how production and marketing systems have changed in response to
the increased demand for organic horticultural products. For those who
began their careers in conventional agriculture, this has also meant
learning how we can work with a diverse and different group of clientele.
The articles from the Organic Horticulture Colloquium are aimed gaining a
better understanding at what the organic movement means and how we can all
adapt to take advantage of the opportunities it presents.


Our work was supported by the University of California's Division of
Agriculture and Natural Resources Competitive Grants Program and Center
for Pest Management Research and Extension, and from the Western Region
Sustainable Agriculture Research and Education Program. We are especially
indebted to Farm Advisor Emeritus Walter Graves, whose perseverance with
testing of cover crop cultivars laid the groundwork for many of our
current organic production systems.

Literature Cited
Aguiar, J., J. D. Ehlers and W. Graves. 1998. Desert Cover Crop
Varieties Identified. In California Vegetable Journal, p. 5,6, 21. Dec.
Brumfield, R., A. Rimal, S. Reiners. 2000. A comparative cost analysis of
conventional, integrated, crop management, and organic methods. HortTech.
Cavanaugh, P. 1998. Cover crops in the Coachella Valley. Vegetables West
Creamer, N. 2000. A training series for cooperative extension agents in
organic farming systems. HortTech. 10:xxx-xxx.
Gaskel, M., R. Smith, C. Fouche, S. Koike, W.T. Lanini, and J. Mitchell.
2000. Organic vegetable production in California. HortTech. 10:xxx-xxx.
Hall, A. E., B. B. Singh, and J. D. Ehlers. 1997. Cowpea breeding. Plant
Breeding Reviews Vol. 15:215-274.
Hutchinson, C.M. and M.E. McGiffen. 2000. Cowpea cover crop for weed
control in desert pepper production. HortSci.35:196-198.
Matthews, W.C., J.D. Ehlers, W. Graves, P.A. Roberts, and J.V. Samons.
1998. Use of resistant cover-crop cowpeas in crop rotations to reduce
levels of root-knot nematode. p.114. Abstract, Annual Meeting of the
American Society of Agronomy.

Miles, C. A. 2000. The development of a research and extension program for
sustainable agriculture in western Washington. HortTech. 10:xxx-xxx.
Ngouajio, M. and M.E. McGiffen, Jr. 2000. Cropping systems of intensive
desert vegetable production. http://cnas.ucr.edu/~bps/hcoopextcrop.html
Stirzaker, R.J. B.G. Sutton and N. Collis-George. 1992. Soil management
for irrigated vegetable production. I. The growth of processing tomatoes
following soil preparation by cultivation, zero-tillage and in-situ grown
mulch. Aust. J. Agric. Res. 44:817-829.
Stirzaker, R.J. J.B. Passioura, B.G. Sutton and N. Collis-George. 1993.
Soil management for irrigated vegetable production. II. Possible causes
for slow vegetative growth of lettuce associated with zero tillage. Aust.
J. Agric. Res. 44:831-844.
Thompson, G. 2000. Consumer demand for organic foods. HortTech. 10:xxx-xxx.
Vischer, D. 1994. Lopez and Sons Family Farm. Small Farm News. May/June
1994, p. 6. Small Farm Center, DANR, Univ. Calif.