From: london@sunSITE.unc.edu (Larry London)
Subject: News from ATTRA: Organic Fruit Production
Organization: University of North Carolina, Chapel Hill
Date: Thu, 19 Nov 1992 04:31:58 GMT

APPROPRIATE TECHNOLOGY TRANSFER FOR RURAL AREAS, P.O. Box 3657,
Fayetteville, AR  72702; 1-800-346-9140


             ATTRA Summary:  Organic Fruit Production


     Planning and establishing a successful organic fruit
operation requires knowing what types and varieties of fruit crops
can be grown well organically in a given location.  Starting with
a solid grasp of organic fruit crop nutrition, pest management,
and marketing strategies is also important for success.

     In general, organic production methods for fruit and other
crops avoid the use of synthetically compounded fertilizers,
pesticides, and growth regulators.  Biologically sound farming
practices (such as cover cropping and mulching) and materials from
natural or biological sources (such as mineral rock powders and
botanical insecticides) are emphasized instead.

     ATTRA has up-to-date information available about organic
certification programs for farms and products.  A variety of
private and state-sponsored organic certification and growers'
organizations now exist.  National organic production and
certification standards are also under development.


Adding Sustainability

     Growing fruit crops, and producing them organically, can
offer several avenues for increasing farm sustainability.  Because
fruit crops are perennial, the soil in fruit plantings may not
need to be disturbed once crops have been planted.  As a result,
fruit crops can be grown successfully on hillsides or on other
farm sites that might erode significantly if planted to annual
crops.  Also, since per-acre monetary returns can be high, fruit
crops may be profitable for the small-scale farmer with limited
access to land.

     Compared to other crops, harvested fruit also removes few
nutrients from the soil.  Organic production methods in general
also protect soil and further enhance both soil structure and
health.  Combined, these features give organic fruit production
appeal as a way to support the financial and ecological
sustainability of a farm.


Basic Considerations

     Crops and location:

     Strawberries, bush fruits, and brambles are generally easier
to grow organically than grapes and tree fruits.  High
susceptibility to a number of hard-to-manage diseases and insect
pests, for example, presents a major obstacle to organic
production of apples and peaches.  In comparison, bramble crops
(such as raspberries and blackberries), for example, tend to incur
less-serious disease and pest problems and are easier to protect
with organic methods.

     Compared with conventional methods, management needs for
organic fruit production may be higher and require methods more
attuned to site conditions.  Climate, soil type, drainage of air
and water at the site, and the kinds of pests and diseased present
can greatly impact the feasibility of producing certain fruit
crops organically in a given location.  Overall, the drier
climates of the West, which foster pest and disease problems less
than do Eastern climates, are more amenable to organic fruit
production.


     Economics and marketing:

     Organic fruit can bring a price premium over conventionally
grown fruit in certain markets.  However, fresh-market cull rates
due to cosmetic imperfections may be higher for organically
produced fruit. In addition, costs for organic fertility and pest
management measures often exceed those for conventional chemical
methods.  Access to markets paying a price premium can be
important to cover these losses and costs.  For highly perishable
fruits, such as blackberries and strawberries, ready markets need
to be identified well before harvest.

     Strategies for handling cosmetic culls can reduce income
losses.  Some growers process and sell edible but cosmetically
imperfect fruit as preserves, juice, and other products. 
Developing a clientele that is aware of the advantages of organic
produce, and more tolerant of cosmetic imperfections, is another
strategy.


Organic Fertility Strategies

     Soil that is moderately fertile and nutritionally balanced,
has a proper pH, and has plentiful organic matter is fundamental
to an organic fruit fertility program.  Acid soil (4.8 to 5.2 pH),
for example, is a basic requirement for blueberries, and berry
crops in general respond very well to additions of organic matter.

     The permanent nature of fruit plantings means that adjusting
soil nutrients, pH, and organic matter will be easiest prior to
planting.  Pre-plant soil amendment and pH needs should be
determined with a soil test.  In organic production, pre-plant
fertility strategies have added importance because most
organically acceptable amendments are not quickly soluble.  For
full effect, the less-soluble amendments should be
soil-incorporated -- but incorporation must be done before
planting to avoid root damage.

     A recommended organic pre-plant regimen to add nutrients and
organic matter to soil is to grow and turn under a cover crop plus
incorporate rock powders and other types of less-soluble
amendments.  Lime and rock phosphate, compost, and cottonseed meal
are examples of these.

     After planting, alternatives to soil-incorporation must be
employed.  Less-soluble types of amendments can be broadcast, but
should be applied in early spring to avoid late-season nitrogen
release.  Soluble fertilizers needing no incorporation, such as
fish emulsion, are available for organic production.  These often
cost more than the less-soluble amendments, but are well suited
for use after planting.  In established plantings, many growers
meet much of their seasonal crop nutrition needs with soluble
fertilizers and foliar feeding methods.  Long-term organic
strategies for supplying fruit crops, especially trees, with
potassium, phosphorus, and nitrogen also include mulching with
organic materials and undersowing legumes.

     Because organic fertilizers may have varying nutrient
contents and release rates, care is needed to determine proper
rates of application.  For more information on using organic
fertilizers for fruit crops, contact ATTRA.


Organic Pest management

     Weeds:

     Strategies for managing weeds in organic fruit plantings also
help to protect soil, support overall pest management, and
maintain soil fertility.  Weed management in fruit plantings is
most important near crop plants where weeds compete most directly
for water and nutrients.  How weeds are managed between rows and
in other areas can also impact insect, mite, and disease
management, soil fertility, and water availability.  Adequate
pre-plant attention to weed problems can greatly simplify weed
management later in established plantings.

     Tactics to suppress weeds in organic fruit plantings may
include:  cultivation, soil solarization, mulching and ground
covers, weeder geese, soap-based herbicides, and flame weeding. 
Weed management by clean cultivation can be undesirable because it
promotes soil and organic matter loss and makes site work
difficult in wet weather.  After planting, shallow cultivation
under plants is sometimes practiced along with the use of ground
covers between rows.  In general, preferred weed management
systems for organic fruit plantings rely mainly on soil-protecting
ground covers and mulches.

     Soil solarization is one organic method for pre-plant weed
suppression.  It involves tightly covering areas of freshly
cultivated, well-moistened soil with clear plastic for four to six
weeks during the hottest days of summer.  Under the plastic, soil
temperatures reach and stay for extended periods at levels lethal
to many weed plants.  Planting and tilling under one or more cover
crops following initial cultivation of the site is another
pre-plant strategy.

     Ground cover strategies using cover crops provide cultural
weed suppression in established fruit plantings.  Properly chosen
and managed, ground covers can add nutrients and organic matter,
increase water infiltration of soil, contribute mulching material,
and/or provide habitat for beneficial insects.

     Mulches are applied directly beneath the crop plants and can
suppress weeds significantly.  Examples of organic mulching
materials are straw, leaves, sawdust, and mowed material from
cover crops.  Mulching with organic materials can beneficially
impact soil fertility, moisture, and temperature.  Woven fabric
mulches, paper, and plastic are also sometimes used.

     Weeder geese are an effective post-plant biological tactic
used in fruit crops against emerging grass weeds.  Soap-based
herbicides that provide effective chemical suppression of emerging
annual weeds may soon be available for use in food crops.  Flame
weeding is used to suppress seedling weeds by searing them.


     Insect and mite pests:

     Effective management strategies for insect and mite pests in
fruit plantings protect plant vegetative parts as well as fruits. 
Because fruit plantings are perennial, an often-used organic
strategy in annual crops -- crop rotation -- is not an option. 
Also, the permanent nature of fruit plantings (especially those
without clean cultivation) may encourage pest populations to build
over time.  However, populations of beneficial organisms may be
maintained more easily, as well.

     Plant health and vigor may play a role in how well fruit
crops recover from insect and mite damage to foliage and stems. 
Good plant health may increase protective responses (such as the
smothering of pests with sap) in fruit crops, and may also reduce
plant attractiveness to pests.

     Genetic resistance to certain pests is available in some
fruit crop varieties through heritable traits that inhibit pest
damage.  In general, genetic resistance pertains mainly to plant
vegetative parts (leaves, roots, stems) rather than to fruit
parts.  Because cultivars resistant to multiple insects are not
available, genetic resistance can be only one part of a pest
management strategy.

     Biological suppression tactics for insect and mite pests use
beneficial microbes, insects, and mites that reduce pest
populations.  Certain species of bacteria, fungi, viruses,
nematodes, and other microbes that are natural enemies of pests
can be mass produced and sprayed on crops.  Used this way, these
organisms are frequently thought of as "biological insecticides"
because they do not reproduce significantly in the field. 
"Bacillus thuringiensis" (Bt) is an example of a commonly used
microorganism.  Examples of beneficial organisms that parasitize
or predate fruit crop pests are predatory mites, lady beetles,
green lacewings, and Trichogramma wasps.

     "Biorational pesticides" are derived from materials found in
nature and/or are materials that break down rapidly and that
appear to have a low impact on the environment.  They are
generally the least-toxic means of chemical suppression available
for certain pests.  Examples of biorational pesticides are:

     - botanical extracts
     - insect growth regulators
     - synthetic pheromones to disrupt mating
     - soaps high in fatty acids
     - dormant oils
     - minerals such as sulfur dust


     Mammal and bird pests:

     Deer, several bird species, rabbits, mice, voles, raccoons,
and other vertebrate animals can be serious fruit pests.  Deer can
devastate fruit plantings -- especially young orchards.  Birds can
be especially damaging to grape and berry plantings; and rodents
that overwinter in mulch can be particularly troublesome in
orchards and blueberry plantings.

     Basic methods for controlling vertebrate pest damage in
organic fruit operations include:

     - non-lethal trapping
     - exclusion with fencing or netting
     - repellant/scare devices
     - winter clearing of mulch
     - mowing to promote raptor predation

Birds and other vertebrate pests learn quickly, and methods may
need to be varied to maintain protection levels.


     Diseases:

     Many fruit diseases are specific to particular species and
varieties of fruits.  However, some types of disease problems are
common to almost all temperate zone fruit crops.  One is fruit
rots.  Fruit rot control can be enhanced culturally by plant
spacing, site selection, and pruning strategies that promote air
circulation and sunlight penetration into plant interiors. 
Another is root rots, caused by organisms especially common in
heavy or poorly drained soils.  Examples of fruit crops with a
high susceptibility to root rots are blueberries, raspberries, and
plums.  Proper site selection is very important for preventing
root rots.

     Examples of other cultural methods for disease prevention
are:

     - maintenance of good plant health

     - removal of prunings and other plant debris from the site

     - removal of diseased plants

     - removal of non-crop host plants or inoculum sources for
       diseases

     Because fruit plants are perennial and represent a
considerable investment, it is important to start with clean
stock.  Choosing cultivars with genetic disease resistance is also
particularly important.  For certain diseases of fruit crops,
genetic resistance is the best or only control.  However, absolute
resistance to a disease -- or resistance to multiple diseases --
in one variety is not typical.

     Organically acceptable fungicides and bactericides are
basically limited to copper and sulfur compounds.  These are
typically less effective than synthetic compounds, and crop
protection requires frequent applications.  However, improper use
of copper and sulfur compounds can harm crop plants.  Sulfur is
also lethal to some beneficial organisms, and copper can
accumulate in soil.

     The best disease-prevention strategy for organic fruit
production is to choose clean, resistant stock, practice cultural
prevention, and use sulfur and copper compounds only when
necessary.  Research into alternative organic fungicides and
bactericides has produced at least one effective microbial
fungicide that is close to market.  Plant and compost extracts are
examples of other materials being tried.


For More Information

     This publication summarizes material from the ATTRA
Information Package:  "Overview of Organic Fruit Production,"
prepared by ATTRA Technical Specialist Guy Ames.  ATTRA also has
available a series of Information Packages on the production of
specific fruit crops using organic or low-spray methods.  These
are:

     - "Organic and Low-Spray Apple Production"
     - "Organic Culture of Blackberries and Raspberries"
     - "Organic Blueberry Culture"
     - "Organic Grape Production"
     - "Organic and Low-Spray Peach Production"
     - "Organic Strawberry Production"

     These Packages on methods for specific fruit crops contain
supplemental information to that in the "Overview of Organic Fruit
Production" Package.  For help with a question on organic or
low-spray fruit production, or to request one of the Packages,
call ATTRA toll-free at:  1-800-346-9140.


             ATTRA Summary:  Organic Fruit Production

     Written by:  Holly Winger
     Editorial and Project Director:  Christine Rugen
     (PageMaker Version Design/Layout:  Jim Tracy)

     June 1992


                    A word about ATTRA and NCAT

     ATTRA is a federally-funded service offering free technical
information on sustainable agricultural production and marketing. 
ATTRA provides tailored responses to individual questions from
farmers, agricultural researchers and extensionists, wildlife
professionals, and others, and also distributes Information
Packages, Summaries, and Resource Lists on a range of general
topics in sustainable agriculture.

     ATTRA is funded by the U.S. Fish and Wildlife Service, Dept.
of the Interior, and managed by the National Center for
Appropriate Technology (NCAT) -- a non-profit organization
incorporated in 1976 to help communities and individuals find
sustainable ways to improve their quality of life using skills and
resources at hand.  The ATTRA staff includes technical specialists
in horticulture, agronomy, livestock production, aquaculture, and
wildlife management, and information specialists in agricultural
information transfer.  Their combined training and experience
includes advanced degrees in agriculture and years in consulting,
research, Cooperative Extension, large-scale farming, organic
market gardening, agricultural writing, and orchard, nursery, and
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