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
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
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
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
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
Ramy also found that organically approved insecticidal soaps caused
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
- 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
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
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
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
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.