Posted August 3,
2004: Every year the evidence builds to show that
biological control and agroecological and organic methods
could supply most of what we need to grow all of our food.
A conference at the International House at UC Berkeley from
July 15-17 covered research being done at the University of
California, all over the state, on biological pest management
and research related to organic production systems. The three-day
conference devoted two days to biological control in general,
with a third day devoted to general organic farming systems
research.
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"You know that a revolution in
pest management is happening when the pest management
specialist of a big Salinas Valley produce company shows
a photo of a young, aphid-infested romaine lettuce plant,
and says “I don’t worry about this anymore
because I know the beneficial insects will catch up and
eat them all." |
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The subject of cutbacks in research funds was brought up repeatedly
as a severe constraint by the researchers at the conference.
Those of us who work in this area have a huge obstacle: a mainstream
scientific, government, and media community that has been completely
swept away by proprietary biotechnological approaches to food
production. Nearly all of the agroecological techniques we use,
many described below, are non-proprietary, that is, they can’t
be patented. Therefore the private sector, with its enormous
investment capital, is not interested in funding us. The proprietary
biotechnology sector gets huge amounts of this money, easily
in the tens of billions. The problem is that they are also
getting our much smaller pool of public, federal funding, taking
somewhere in the ballpark of 85% of agricultural research funds.
We, the agroecologists and biological control specialists, with
only farmers and consumers as our backers and beneficiaries,
literally get thrown the crumbs.
There is a building awareness that public moneys, federal
tax dollars, should be devoted to research on non-proprietary
approaches to food production and not to proprietary technologies
that already have huge sources of funding in the private sector.
After all, the agroecological approach will likely provide
most of the solutions to food production constraints in the
future.
Below I review the conference presentations, many of which
are good examples of what I mean when I talk about non-proprietary
approaches to agriculture. All in all, the conference was
very informative, showing an impressive amount of organic-relevant
research coming out of the UC system. But despite the results
from the researchers discussed below, most are looking at
cutbacks in their funding.
Biofumigation, part 1. Krishna Subbarao
of the UC Davis reviewed his research on using cruciferous
cover crops to reduce diseases, known by some as biofumigation.
Broccoli is particularly effective on the Verticillium wilt
fungus, V. dahliae. His early observation is that
the numbers of certain actinomycetes and bacteria increase
by 100- to 1000-fold. Each cruciferous crop has its own type
of glucosinolate, and broccoli’s is effective on V.
dahliae.
Biofumigation, part 2. Oleg Daugovish of
UC Cooperative Extension, Ventura County, described how “biofumigation”
with yellow and oriental mustard cover crops reduced citrus
nematode and Phytophtora root rot by 90%. Biofumigation may
not be the correct term, as Daugovish noted that beneficial
fungi such as Trichoderma have been found at much
higher levels in the mustard treated soils. This does not
occur when the soil is fumigated with chemicals. Mustard cover
crops are now commonplace in the Salinas Valley.
Mustard’s effects on weed seed germination can be significant
in the lab, but field trials have not shown significant results.
The mustards had no effect on Verticillium, contrary to the
significant effect that its cousin broccoli (all are Brassicaceous)
had on this pathogen.
Tripping up the thrips threat. Mark Hoddle
of UC Riverside has reduced the emergence of thrips by half
from soil under avocado trees by mulching with compost. As
with many orchard pests, thrips pupates in the orchard soil.
Predatory mites, Collembolans, beetles, and entomopathogenic
fungi and nematodes may be responsible for the reduction in
thrips. He saw higher levels of the entomopathogenic fungus
Beauvaria bassiana in the mulched soils. [Entomopathogenic
is a big word that simply means that these fungi and nematodes
are a threat to insects.]
Soils that suppress plant parasites. J.
Ole Becker of UC Riverside discussed the development of soils
that are suppressive to plant parasitic nematodes. This type
of suppressiveness, such as of cyst nematode in sugar beet,
develops only after five or six years of growing the same
crop in the same soil. The suppressiveness is transferable
with small amounts of soil from one soil to another, and appears
to be microbiological.
This may explain some of the rationale behind such agricultural
approaches as Natural Agriculture practiced by Shinji Shumeikai,
in which a crop is grown year after year in same plot.
And now a word about the politics of research …
The inimitable Miguel Altieri of UC Berkeley discussed
the importance of the balancing of both the diversity of the
plant community and soil fertility in maintaining the integrity
of agroecosystems. He reviewed research on insect predation
on pest crops as affected by soil nitrogen.
Altieri then threw in a few references to the uselessness
and harmfulness of transgene crops, to which the other University
of California panelists later responded with carefully worded
statements putting themselves as neutral to or advocating
transgenics. University faculty here seem to be under intense,
albeit indirect, pressure to advocate for – or at least
take a neutral stance on – transgenics. A case in point
is Ignacio Chapela. He was denied tenure this spring despite
near-unanimous support from experts within Berkeley and around
the world. This follows his critique of a $25 million research
agreement between the university and Novartis, and then his
publication of research showing that transgenic DNA has contaminated
native corn in Mexico.
Cultivating beneficial insects. William
Chaney of UC Cooperative Extension in Salinas discussed insectary
plants which provide nectar for beneficial insects in vegetable
crops. (Many beneficial insects have a nectar feeding stage,
after which they lay eggs on neighboring plants, such as crops.
When the larvae emerge they feed voraciously on aphids and
other pestiferous insects.)
According to Chaney and other presenters, the criteria for
selecting insectary plants are: attractiveness to beneficial
insects; an early and long bloom period; low potential to
host crop viruses; ability to out-compete weeds; low potential
to become a weed; low attractiveness to pest species; and
low cost of seed and establishment. His preferred mixture
is sweet alyssum, seed coriander, buckwheat, and a cereal.
The cereal acts as a windbreak and as a host for beneficial
insect alternate prey.
Sweet alyssum has really taken off in the Salinas Valley
and coastal areas of California as an insectary plant for
vegetable crops, planted as about 5% of rows or crop land.
Syrphid flies, of numerous species, also known as hover flies,
have become the prime beneficial insect to attract.
One of the notable observations that Chaney mentioned was
that aphid flare-ups have resulted from applications of spinosad,
the new organically approved pesticide (Entrust®), a classic
effect of pesticides. This may be due to the killing of the
syrphid fly’s host, the aphid, leaving the syrphid without
a food source, or due additionally to the soap’s lethality
on syrphid flies. Spinosads have been taking some organic
pest control programs by storm. Very little work has been
done in the area of the effects of organically approved pesticides
on beneficials.
Habitat management for pest control. Ramy
Colfer, who did his Ph.D. at UC Davis at the same time and
in the same department as I did, and who now works for Mission
Organics in Salinas, the largest grower of organic salad mix,
described his work with insectary plants and habitat management
for pest control. He plants every 20th row of lettuce to sweet
alyssum, makes sure it blooms as early as possible, and has
successfully reduced lettuce aphid infestations to where crop
loss has been 1% or less – quite an accomplishment in
an industry that routinely writes off entire fields to aphid
infestations.
Ramy also found that organically approved insecticidal soaps
caused aphid flare-ups.
You know that a revolution in pest management is happening
when the pest management specialist of a big Salinas Valley
produce company shows a photo of a young, aphid-infested romaine
lettuce plant, and says “I don’t worry about this
anymore because I know the beneficial insects will catch up
and eat them all.
Is it allowed organically? Ray Green of
the California Department of Food and Agriculture clarified
the different ways to determine if a substance applied to
organic crops is in or not in compliance with the USDA National
Organic Program (NOP) if it hasn’t yet made the OMRI
list. Green’s first caveat, which elicited laughs was:
“All natural compounds are allowed unless prohibited;
and all synthetics are prohibited unless allowed.” In
California, any one of the following criteria generally make
it safe to apply a material, if the material:
- Has a written endorsement by any USDA accredited certifier.
- Is on the Washington State Department of Agriculture
list of materials, which is on its website. The WSDA is
a USDA NOP accredited certifier.
- Has the manufacturer’s written self-disclosure
that the material is in compliance with the USDA rules.
There are substantial legal disincentives in California
for manufacturers to fraudulently declare a material’s
compliance, according to Green.
- The material is a single substance, like a plant extract.
- The US EPA has endorsed the material for use in organic
systems. They have a green flower seal for these materials.
Stink bug strategies. Les Ehler of Entomology
at UC Davis described how to reduce stink bug problems by
manipulating the farmscape. In California, where the consperse
stink bug, one of many types of stink bugs around the US,
is a problem, elimination of winter habitat and early season
food sources are the keys. Blackberry patches are particularly
important winter habitat. Brassicaceous weeds, such as mustards
and wild radish, are important early season food sources and
need to be kept down.
Organic pest control products: costly to develop.
Barat Bisabri of Dow AgroSciences reviewed the development
of their spinosad products, Entrust® and GF-120 NF®.
Entrust, is a spray, now well-known to many organic growers,
and GF-120 NF is a bait, now being used to effectively control
the olive fruit fly, the Mediterranean’s worst olive
pest, which invaded California’s olive groves several
years ago.
Bisabri noted that the actinomycete that spinosad compounds
are isolated from was found in an abandoned rum distillery
in the Caribbean in 1982. The product was licensed in 1997,
making it a 15-year lag from discovery to commercial release
of product, typical of the industry.
Four criteria need to be satisfied, according to Bisabri,
in order to develop new pest control products: efficacy; IPM
friendliness; resistance manageability; and environmental
profile. Few new organic products are on the horizon because
of the high development costs and small organic market.
The impact of organic insecticides on beneficials.
Marshall Johnson of Entomology at UC Riverside presented the
results of a survey of research on the lethality effects on
parasitoid and predator natural enemies of two of the most
common organic insecticides: spinosads and neem/azadirachtin
materials. He found that most beneficials were negatively
affected (86%). Most affected were the parasitoids by spinosads;
these somewhat less so by the neem products. Neem had a relatively
greater effect on predators than spinsads. The entomopathic
microbes Beauvaria and Bt had less of an effect on
beneficials than the other two compounds.
“N” gets boost from compost.
Willy Horwath of UC Davis reviewed organic matter in organic
farming systems, noting that when composts are applied just
before or following cover crop incorporation, there is a catalytic
effect on nitrogen release. The compost stimulates the active
organic fraction in the disked-in cover crop biomass to release
N.
“N” boost, part 2.” Mark
Gaskell of UC Extension also discussed organic matter management
for N supply to organic crop systems. The peak N demand period
for crops generally lasts for 30-60 days starting 25-40 days
after seeding. Gaskell maintains that keeping a soil nitrate
level of a minimum of 20 ppm is important. Again, the importance
of cover crops as an N-releasing base, on top of which is
put the organic fertilizers, was emphasized. The application
of organic fertilizers could be reduced from 220 to 120 kg/ha
of N with a cover crop base.
(These numbers seemed high to me, and since nitrogen nutrition
is such an important part of organic farming, I called compost
expert Ralph Jurgens of New Era Farm Services in Tulare, CA,
who has many organic farmer clients. Jurgens concurred that
the compost application rates of 100 to 200 kg/ha of N are
high. This would be on the order of 25-50 tons per hectare
of composted manure, which generally averages 2-3% N. Phosphorus
overloading from composts and manures has become a problem,
and N availability and release rates from organic sources
are not well-understood. Jurgens gets enough N to the crop
using cover crops and much lower rates of compost applications
- around 3-5 tons per hectare per year. Much still needs to
be sorted out in the area of compost, cover crops, and crop
nitrogen needs.)
Best cover crops. Eric Brennan of USDA-ARS
Salinas, California, the first USDA scientist whose job is
dedicated to organic crop systems, discussed his research
on three cover crop factors: seed cost, seeding density, and
weed competitiveness. He planted a legume-rye mix, mustard
alone, and rye alone, each at 1x and 3x recommended rates.
He found that the 1x legume-rye allowed 20 times more weed
biomass than any of the other treatments. The 3x rates of
all of the cover types had about twice the early season (November)
biomass, which is good for sequestering nitrogen and preventing
nitrate leaching. By late season (February) the biomass had
equalized between the two seeding rates.
Another problem with the legume-rye blend is that the legume
ends up with only about 10% of the total biomass compared
to rye, which means that little N is likely being fixed into
the system; yet the legume accounts for 90% of the cost of
the seed.
Organic peach management. Janine Hasey of
UC Cooperative Extension, Yuba City, discussed her research
on peach orchard floor management. Subclover plus soft chess
were good floor covers, providing adequate N. She noted that,
in regards to transitioning to organic, it is easier to transition
an existing peach orchard than to start an orchard as organic,
mostly because of the effect of the mature canopy on reducing
weeds.
Organic research funding review. Sean Swezey,
director of the UC Sustainable Agriculture Research and Education
program, reviewed the sources of funds going into organic
agriculture at the federal and state (CA) levels. Federal
programs are:
- $15 million in grants from CSREES (Cooperative State
Research, Education, and Extension Services) to be disbursed
in September;
- $1.9 million for the Organic Transitions program;
- the USDA Economic Research Service is spending half a
million to collect organic commodity price data;
- the USDA ARS (Agricultural Research Service) national
organic workshop has some 100 researchers who are engaged
in some form of organic research.
- The UC system alone now has some 60-70 researchers engaged
in some form of organic farming or food research.
Swezey made an interesting comment that California’s
organic value at the farm gate is $350 million, while the
organic processors declared a value of $5 billion –
an approximate 15-fold value increase – putting the
value-added aspect of organics in perspective. Of course,
the comparison doesn’t take into account that processors
import some organic products for processing, but the statistic
is still illustrative.
Strawberry suction reduction. Swezey also
reviewed his research on the lygus bug in organic strawberries.
Currently, large organic growers use large vacuum machines
to suck up the pest. Swezey showed that alfalfa as a trap
crop, planted every 16th row, is so attractive to the lygus
bug that just vacuuming the alfalfa rows gave better control
of the lygus than entire-field vacuuming, and reduced vacuuming
by 75%.
What are the research needs of organic?
Mark Lipson of the Organic Farming Research Foundation reviewed
research needs for organic systems and noted that the weak
areas of research have been in plant breeding (see my upcoming
article on horizontal disease resistance breeding in Mexico)
and in livestock management. Strong areas of research on organic
systems have been on soil quality and biological control of
pests.
Organic numbers, part 1. Karen Klonsky,
agricultural economist at UC Davis, reviewed California’s
organic statistics. The highest grossing organic commodity
is grapes, followed by lettuce, carrots, strawberries, and
tomatoes. Rice is tops in acreage, followed by grapes. In
the last ten years, the number of farmed acres grew much faster
than the number of growers increased. This has been driven
by two things – the expansion of existing farms, and
the higher relative growth recently of organic grain and field
crops, such as rice, which have larger acreages per farm than
vegetable and fruit crops.
California has kind of a “developing country”
situation in that large growers, making up 3% of total farmers,
produce 55% of crop value, while small growers, making up
50% of all growers, produce only 2% of total value.
Organic numbers, part 2. Desmond Jolly of
UC Davis, summarizing the sociology of California’s
organic farmers showed that, on the average, organic farmers
are more educated (61% vs. 37% are college grads), and use
computer technology at nearly twice the rate of their conventional
counterparts.
Soda bottles vs. the olive fruit fly. Paul
Vossen of UC Extension in Sonoma County described how low-tech
soda bottle traps for the olive fruit fly, developed in Spain
using Torula yeast as an attractant, were the best and lowest
cost of all traps tested. The spinosad bait product GF-120®,
tested separately, was effective also.
Organic herbicides not great. Karen Baumgartner
of USDA-ARS Salinas compared the organic herbicide Matran®,
a vinegar and clove oil based product, with other treatments,
including Roundup®, showing that organic herbicides have
a long way to go to catch up with the Monsanto product. Matran
was most effective on broadleaved weeds.
Sub-surface irrigation reduces weeds. Tom
Lanini of UC Davis discussed his research on the effectiveness
of sub-surface drip emitters for nearly eliminating weed seed
germination in dry summer areas like California. The drip
emitters are buried 10 inches deep.
In regular sprinkler and furrow irrigation systems he tested
pre-irrigation to germinate weeds, which are then disked.
He found that 110 to 130 degree days (about six days, averaging
30° C, with a base calculation temperature of 10°
C) was optimum to get them up before disking them in.
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