|
Sample
spray schedules
for organic apple production in the Northeast
By Don Jantzi and Jeff Moyer
Below are three possible spray schedules based
on our experiences here at The Rodale Institute®
in Berks County, Pennsylvania. Sample #2 was the
schedule we used in 2003, and sample #1 is what
we hope to do in 2004.
NOTE: Our management decisions
are geared towards producing as large a quantity
of grade A table fruit as possible; growers with
other objectives—such as cider production—will
want to make adjustments accordingly.
Sample spray schedule
#1
Lime sulfur
and/or sulfur on scab-susceptible varieties beginning
at green tip.
Pyganic®
(pyrethrum) to control leafroller, plum curculio,
fruitworm, European sawfly, at pink and/or at
petal fall.
Surround®
(kaolin clay), petal fall through June.
Entrust®
(spinosad) and Dipel®
(Bt) to control second generation codling moth,
mid-July or August.
Pheromone mating
disruption for codling moth and
Oriental fruit moth, beginning at bloom.
Sample spray schedule
#2
Lime sulfur
and/or sulfur on scab-susceptible varieties as
needed, beginning at green tip.
Surround®,
full season coverage beginning at pink or late
bloom and continuing as needed to maintain thick
coating through early August.
Sample spray schedule
#3
Sulfur
as needed, beginning at green tip.
Neem spray
(Aza-direct®, Neem
oil, Agroneem®, or
Neemix®) as a fungicide
for summer diseases and a summer insecticide for
various insects, at pink and/or petal fall.
Dipel®
and/or Entrust®
for internal worm, late summer.

|
|
|
Resources
Guy Ames, Considerations
in Organic Apple Production (ATTRA Organic
Matters Series, 2001)
Disease
Management Guidelines for Organic Apple Production
in Ohio (West Virginia University Tree Fruit
Research and Education Center)
Management
Guide for Low-Input Sustainable Apple Production
(jointly published by Cornell Univ, The Rodale
Research Center, Rutgers Univ, Univ, Univ of Massachusetts,
Univ of Vermont)
North American Fruit Explorers (NAFEX)
www.nafex.org
Stephen Page and Joseph Smillie, The Orchard
Almanac: A Seasonal Guide to Healthy Fruit Trees
(agAccess, 1996)
Michael Phillips, The Apple Grower (Chelsea
Green, 1998) Note: Phillips is reportedly working
on a revised edition covering the latest materials,
including Surround. |
|
|
 |
May 11, 2004: The USDA Economic Research Service
tells us that in 2001 (the most recent year for which totals
are available) there were 12,189 acres of certified organic
apple orchards nationwide, up from 9,270 in 2000. But just 633.3
of those acres, or about 5 percent, were east of the Continental
Divide.
While Eastern and Midwestern states like New York, Pennsylvania,
Michigan, and Wisconsin have long histories of fruit growing
and strong—if struggling—apple sectors, growth
in the organic apple business has been largely restricted
to Western states like Washington, Arizona, and Idaho, where
drier growing conditions translate into drastically reduced
pest and disease pressures.
Eastern fruit growers face twice as many problem diseases
as their Western counterparts (including fireblight, scab,
black rot, and cedar apple rust) in addition to no fewer than
60 species of damaging insects. The single most destructive
insect pest for Eastern growers—the infamous plum curculio—is
unknown in the West. The geographic disparity is so great
that Eastern tree fruit growing is widely regarded as "the
final organic frontier," as Michael Phillips put it in
his The
Apple Grower: A Guide for the Organic Orchardist (Chelsea
Green, 1998).
If that phrase sounds like it contains a challenge—a
throwing down of the gauntlet for organic practitioners, it's
because, well, it does. Apple growers may seem like a soft-spoken
bunch, but they're stubborn, too; and their determination
to find organic solutions to Eastern production problems springs
from a fierce loyalty to the region, the work, and the way
of life.
Eastern apples have more flavor than Western apples, declares
Don Jantzi, who grew up on a family apple farm near Buffalo,
New York, and has been orchard foreman for The Rodale Institute®
Experimental Farm since 1986. "Western soils tend to
be sandier, and those sandy soils give less flavor,"
he explains. Eastern growers, moreover, have a broader range
of varieties to choose from than their Western counterparts,
which means that "Eastern growers tend to be more independent.
Out West, the marketing programs are so advanced that growers
are more locked into a certain set of varieties." And
as anyone who's been to a supermarket lately knows, those
dominant Western varieties have grown steadily more tasteless
over the years as they have been further selected for color,
uniformity, and durability under shipment.
Pennsylvania State University fruit researcher Jim Travis
goes even further, arguing that what is widely regarded as
the humid East's greatest liability for organic fruit production—large
and vigorous insect populations—could eventually be
seen as its greatest asset. "Look at this biodiversity,"
he says, gesturing at the rich spring scene, bumblebees staggering
through the air, green grass and dandelions and flowering
trees bursting out as far as the eye can see. "Western
fruit producers are growing in the desert. They don't have
all this to work with."
The upshot is that despite the difficulties, Eastern fruit
growing remains viable. "If you have a good market for
processed products—like baby food, dried apples, juice,
or sauce—or if you have a good direct marketing strategy,
like a pick-your-own operation or farmstand," Jantzi
says, "you can make it work."
Deep roots
The Rodale Institute Farm currently maintains about 1100
apple trees on a total of just under six acres. The oldest
trees here were established in 1981, but the majority were
planted in 1990, when an apple production project was launched
with support from the USDA's old Low-Input Sustainable Agriculture
(LISA) program (the precursor to the Sustainable Agriculture
Research and Education program, or SARE). That project brought
together researchers from Rodale, Cornell University, Rutgers
University, the University of Massachusetts, and the University
of Vermont, and yielded (among other things) an 84-page Management
Guide for Low-Input Sustainable Apple Production, which still
serves as a valuable reference for the running of the orchard
today.

 |
|
After the research agenda wound down, a decision was made
to continue managing the trees for production purposes alone.
"Our goal was to maintain the orchard and to meet the
challenge of staying on top of new management strategies as
they became available," says Jantzi.
Today, it looks like that strategy may be literally bearing
fruit. Evolving market conditions and new materials are making
organic apple production in the East more attractive than
ever. And there is now talk of initiating a new research agenda
in the Rodale orchards in collaboration with Pennsylvania
State University (for more information on that, click
here.)
Traditional management, with a few key
differences
Many aspects of organic apple production would be perfectly
familiar to conventional orchardists. Organic managers adhere
to the same basic principles when it comes to selecting a
site for a new orchard, choosing rootstocks, pruning, and
staking or trellising trees. "There's an organic grower
in New York who maintains that natural trees"—that
is, non-grafted, seedling trees, grown on their own rootstocks—"are
stronger and easier to keep healthy than regular grafted trees,"
notes Jantzi. Most organic growers, however, including The
Rodale Institute farmers, continue to work with grafted trees
because they are easier and less hazardous to prune, thin,
spray, and harvest. Independent of other factors, organic
growers tend to favor wider tree spacings in their orchards,
and "may want to be more diligent in their pruning,"
Jantzi says, since they need to rely more heavily on factors
like air circulation to reduce disease.
One area in which organic orchard establishment may differ
sharply from conventional practice is in the selection of
varieties. Since the mid-1980s, breeders have been releasing
a series of disease-resistant apple cultivars, including many
that are resistant to apple scab and others that show resistance
to rust, fire blight, powdery mildew, or fruit rots. Rootstocks,
too, vary in their susceptibility to certain diseases. While
some growers reject the disease-resistant varieties in favor
of more recognizable—and therefore more marketable—cultivars,
Jantzi emphasizes that "there are good scab-resistant
varieties out there." Organic growers can make their
lives a little easier by including a handful of disease-resistant
varieties in their orchard mix.
"Good," it should be noted, is a strictly relative
term for apple growers, since there are so many qualities
making up a desirable apple, from tree maturation, growth
habit, and blooming period, to yield, fruit size, color, texture,
flavor, and storage characteristics. As any grower will tell
you, successful orcharding requires a combination of early,
mid-, and late season varieties both to spread out the risk
of weather and pest susceptibilities and to extend the marketing
period over as many weeks as possible.
The Rodale Institute orchards include both scab-susceptible
and scab-resistant varieties; there are also a couple of heirloom
varieties that happen to be fairly scab-resistant, including
Tydeman and Brown Russet. Because of their research history,
the trees here include a wider assortment of varieties than
most growers on this scale would have: 39 altogether, from
early-season cultivars like Lodi, Jersey Mac, and Williams
Pride to late-season favorites like Rome and Granny Smith.
"Some of the varieties we have I would not plant again,
but you work with what you have," observes Jantzi.

 |
|
The farm's younger orchard is dominated by three varieties:
Liberty, NY 74828-12, and NY 75441-67. Liberty is a Macintosh-type
apple and one of the most common scab-resistant varieties;
Jantzi says it tends to be pretty consistent in its fruit
bearing, has a good red color, and is good for both baking
and eating fresh, but doesn’t store particularly well.
The two numbered varieties were obtained on a research basis
but were never released commercially and thus were never assigned
names. Nevertheless, Jantzi says they've proven their worth
on this particular site.
The orchard floor
"There's lots of debate about when and how much to mow,"
Jantzi says. "We mow fairly constantly through the growing
season, for aesthetic reasons, but some growers and researchers
argue that letting the grass stand under the trees encourages
more beneficial insects." On the other hand, Jantzi reports
that whereas in earlier years Rodale's orchard managers released
packaged beneficial insects, he no longer does this since
beneficial insect populations—including ladybugs, lacewings,
honeybees, flies, spiders, wasps, insidious flower bugs, predatory
mites—are now healthy without supplementation.
For additional weed management, Jantzi goes through with
the Weed Badger about four times a year, clearing an 18-inch
strip along the base of the trees. The aggressive cultivating
tool is effective but time consuming, Jantzi says, making
weed management another area in which organic growers have
to spend more on labor than conventional growers do.

To maintain fertility in the orchard, Jantzi puts down roughly
100 lbs of compost per tree per year ("Depending on who's
doing the shoveling," he notes). They used to spread
in the spring, but a few years ago switched to spreading in
the fall, when the compost can help the fallen leaves and
waste apples decompose over the winter.
A new generation of organic pest control
materials
There's no way around it: pest and disease management are
a big part of orcharding in the humid East. Problem diseases
include apple scab, flyspeck, sooty blotch, powdery mildew,
fire blight and cedar apple rust, and the list of major insect
pests is even longer, from the plum curculio, to the oblique-banded
leafroller, red-banded leafroller, tufted apple bud moth,
codling moth, Oriental fruit moth, lesser appleworm, and European
apple sawfly.
The cornerstone of low-input orchard management is good monitoring.
Each year, Jantzi hangs a series of insect traps in selected
trees to keep tabs on pest populations. The traps use pheromone
lures or visual and/or scent mimicry to attract specific pest
species, and can be used both to calculate the economic threshold
at which spraying is justified and to determine the optimum
moment to spray.

"Most insects are most vulnerable at egg hatching stage,"
Jantzi explains, "so that's when you want to target your
spraying." It's also possible to anticipate pest cycles
by keeping track of degree days—the accumulated warmth
(as represented by mean daily temperature) above a 50°F
base temp. Codling moth eggs, for instance, will begin hatching
243 degree days after the first moth is trapped. Of course,
such calculations have to be balanced by weather conditions
when it comes to the actual spray schedule. "You go for
the ideal," as Jantzi puts it, "and then you do
what the weather will allow."
Pheromones are also used for active pest management in the
form of mating-disruption cards—small plastic cards
which release female insect sex hormone odors and thereby
confuse the males as they attempt to mate. Jantzi relies on
mating-disruption to manage Oriental fruit moths and codling
moths. "They say that for the pheromones to be effective
you need a minimum orchard size of 5 acres, and your orchard
should be as square as possible," he points out. The
Rodale Institute orchards don't quite fit those parameters,
but Jantzi feels the cards offer the best solution for handling
these pests.
Probably the most radically new product for organic orchard
management is the kaolin clay product known as Surround®.
Developed in the late 1990s by two USDA Agricultural Research
Service scientists in cooperation with the Engelhard Corporation
of Iselin, New Jersey, Surround is based on what's called
'particle film technology.' Rather than killing target insects,
it forms a white, powdery film on the leaves, branches, and
fruits, making them unattractive or unfamiliar to the insects.
The idea was originally developed as a possible disease-control
mechanism; but researchers discovered that while it had no
effect on diseases, it was highly effective against nearly
all the major apple insect pests. There is also some evidence
that Surround increases net photosynthesis by keeping plants
cooler in the hottest part of the day.

 |
|
Jantzi and Jeff Moyer, Farm Manager at The Rodale Institute,
made frequent use of Surround in 2003, but were not totally
happy with the results—in part because last year's heavy
rains made it difficult to keep a coating built up. This year,
they're planning on concentrating the Surround coverage within
a shorter window, starting about two weeks later and ending
about six weeks earlier, and then turning to other materials.
Other, relatively new, organic pest control materials Jantzi
and Moyer plan on trying in the coming season include spinosad
(marketed by Dow under the brand name Entrust®),
a fermentation product derived from a soil-dwelling actinomycete;
and some of the neem products like Aza-Direct®
(named from azadirachtin, the active ingredient extracted
from the seeds of the neem tree). "There are some studies
that have shown [Aza-Direct] to be effective, but others have
found it not to be effective," notes Jantzi. "People
are still figuring out the best ways to use these new materials."
The New Hampshire-based organic orchardist Michael Phillips
has been experimenting with the use of whole neem oil (as
opposed to derived neem products), on the grounds that it
might be more effective and that it's economically preferable
to purchase the natural insecticide in a less processed form,
as close to the original producer as possible.
Most of these products can be tank-mixed, so if the timing
is right they can be combined to make fewer trips through
the orchard. Part of what's revolutionary about new materials
like Entrust and Pyganic® (a pyrethrum
product) is that in contrast to most organic-approved products,
they work against a variety of pests. "That kind of runs
counter to organic thinking, where you're trying to minimize
impact on beneficials," Jantzi observes. But the new
materials are expensive, too, so growers are inclined to use
them conservatively.
The bottom line
Acre for acre, apple yields can be as good in organic as
in conventional, Jantzi says, although they tend to be lower
for a couple of reasons—the lack of organic-approved
growth regulators for thinning, and the related tendency of
varieties to fall into a biennial bearing habit. The Rodale
Institute farm orchards average around 600 bushels per acre.
A portion of the harvest is sold direct to the public through
The Rodale Institute bookstore, both pick-your-own and ready-picked.
The balance goes for processing, some sold wholesale for organic
cider and some custom-processed into apple butter for direct
sale.
Jantzi is quick to point out ways in which the orchard set-up
here is far from perfect—the scale, for instance, is
too small for commercial independence, too large for the available
labor. He is intimately familiar with the challenges of apple
growing and the hazards of making the switch from conventional
to organic management. Although he draws inspiration from—and
compares notes with—an annual gathering of Northeastern
organic apple growers, he still says he knows "more people
who have tried it and quit than tried it and continued."
"I think every grower has it in the back of their mind
that they'd like to get away from using pesticides, but there
are a lot of things you have to consider," he cautions.
It may make more sense to think about gradual steps on the
way to certified organic production, Jantzi says, rather than
an all or nothing approach. Above all, "You have to educate
yourself about what's possible, both in terms of production
and in terms of marketing." And what's possible is expanding
all the time. 
Laura Sayre is senior writer for The New Farm.
|