PESTICIDES IN AGRICULTURE AND THE ENVIRONMENT - CHAPTER 7 pot

In manyinstances the industry is initiating research to include these products for use on a variety of minor crops in addition to the more lucrative major crop markets.. In other cases,

Agricultural Research Service

U.S Department of Agriculture

Beltsville, Maryland, U.S.A

The variety of agricultural commodities commonly referred to as “minor crops”

is nearly limitless They include the vegetables, fruits, nuts, herbs, and an increasing variety of ethnic produce that are commonly found in the fresh foodssection of the local supermarket But minor crops also include commerciallygrown ornamental plants such as trees, shrubs, flowers, and turf grass that areproducts of the rapidly growing ‘‘green’’ industry Minor crops suffer from thesame pest depredations as the large-acreage major crops and often require special-ized pest management practices, including pesticides, to produce a healthy, attrac-tive, and nutritious product for the consumer

ever-Historically, producers of agricultural commodities have depended uponthe agricultural chemical industry to provide them with safe and effective chemi-

* Retired.

cal pesticides that supplement their pest control practices in order to maintaincrop yields and protect the health of animals As the cost of meeting regulatoryrequirements has increased, pesticide registrants have concentrated their registra-tion efforts in areas where they could obtain sufficient economic returns to justifytheir research and development costs This resulted in greater registrations ofpesticides for the large-acreage crops such as corn (72.6 million acres), cotton(10.7 million), soybeans (70.8 million), and wheat (59.0 million) [1] Producers

of fruits, nuts, vegetables, and specialty crops such as cranberries, flax, hops,mint, sunflowers, and ornamentals found that they had fewer and fewer pesticidesavailable to them compared to growers of the major crops When minor cropsare considered individually, the acreage of most of them is relatively small How-ever, the combined acreage of these crops in the United States exceeds 11 millionacres, which represents an annual value of more than $39 billion and accountsfor 40% of all U.S crop sales [2] Twenty-seven states have minor crop salesexceeding 50% of their total crop sales (see Appendix 1) Among these are Cali-fornia with greater than $14.3 billion, Florida with $4.7 billion, Washington with

$2.3 billion, Oregon and Pennsylvania with $1.4 billion, and Georgia with $1.0billion

There has been general agreement over the years that a minor use of a pestcontrol product is any use for which the volume is insufficient to justify the cost

to a commercial registrant to obtain a registration This may relate to the general

or frequent use of a product on a low volume crop, or it may apply to the quent or localized use of a product on a high volume crop In either case theproblem of obtaining clearances for the minor crop/minor use market is primarilyone of economics Traditionally, all crops except corn, cotton, soybeans, andwheat have been considered minor crops in the United States However, recentlegislation enacted by Congress clearly defines minor use in terms of cropacreage

infre-The recently amended Federal Insecticide, Fungicide and Rodenticide Act(FIFRA) defines the term “minor use” as any use of a pesticide on a commercialagricultural crop where the total U.S acreage for the crop is less than 300,000acres or the Administrator of the U.S Environmental Protection Agency(USEPA) determines that the use does not provide sufficient economic incentive

to support the initial or continuing registration of that pesticide [3] The definitionfurther states that the Administrator may determine that a minor use exists if thereare insufficient alternatives available for use on the crop, that the alternatives posegreater risk to the environment or human health, or that the minor use pesticideplays a significant part in the management of pest resistance or in integrated pestmanagement systems A list of crops grown in the United States on less than300,000 acres is shown in Appendix 2

Limiting the acreage of a minor crop to less than 300,000 acres initiallyexcludes certain crops that were formerly considered to be minor crops These

include, for example, sunflowers for seed, dry edible beans, white potatoes, ghum, tomatoes, apples, grapes, almonds, and pecans (see Appendix 3).Although federal legislation now contains provisions for expediting the reg-istration and reregistration of pest control products for minor uses, the economics

sor-of obtaining initial registrations and retaining registrations through the tion process has been and will continue to be a serious threat to the production

reregistra-of an abundant and diverse supply reregistra-of high quality commodities in the UnitedStates The significant time and expense required to develop data to support theregistration of new chemicals and to defend existing uses leave pest control pro-ducers fewer resources for minor use registrations

This situation was exacerbated by the enactment of the 1988 amendments

to FIFRA, which required that all pesticides and their uses registered prior toNovember 1984 be reregistered by the end of 1997 At that time, experts esti-mated that 25% of existing tolerances for pesticides registered for use on foodcrops would not be supported by their registrants This was forecast to haveparticularly serious implications for growers of minor crops and for minor uses

of pesticides on major agronomic crops This scenario came to be known asthe “minor use dilemma” and focused attention on the need to accelerate thedevelopment of pest management alternatives on minor crops

Subsequently, the passage of the Food Quality Protection Act (FQPA), inAugust 1996, which amended FIFRA, contained provisions that will ultimatelyfurther limit the availability of pesticides for minor uses The new law established

a single health-based safety standard and required the USEPA to use up to anextra tenfold safety factor to protect infants and children The act further requiredthe USEPA to reassess all existing tolerances and exemptions for both active andinert ingredients within 10 years

It is clear that conventional pesticides will continue to play a primary role

in agricultural crop protection for both major and minor crops It is equally clearthat new chemicals being developed will need to address current environmentalconcerns The agricultural chemicals industry is making significant strides in de-veloping effective pesticides that exhibit greater safety for the environment andnontarget species and are generally used at very low rates of application In manyinstances the industry is initiating research to include these products for use on

a variety of minor crops in addition to the more lucrative major crop markets

In other cases, industry, crop producers, and the public sector are forming ships to extend registrations to minor crop markets where distinct environmentalbenefits exist compared to currently registered pest control products

partner-Although still a very small segment of the commercial pest managementindustry, biological pest control agents, including microbial and naturally oc-curring biochemicals such as pheromones, are increasingly attractive alternatives

to conventional pesticides Collectively known as biopesticides, they generallyexhibit a high degree of safety, low environmental impact, and excellent compati-

bility with integrated pest management (IPM) programs However, they tend to

be very selective in their spectrum of pests controlled This often results in a lowvolume of use, which is unattractive for commercial development, particularlyfor minor crops, despite their typically lower registration costs

It has long been recognized that public sector research is needed to ment the private sector in providing for safe and effective pest management Thishas been especially true for minor crops because of the economic considerations

comple-of registering pesticides for low volume uses Consequently, in 1962 the StateAgricultural Experiment Station (SAES) directors responded to grower needs forassistance in the area of minor crop pesticide registrations and asked the U.S.Department of Agriculture’s (USDA) Cooperative State Research Service(CSRS), now known as the Cooperative State Research, Education and ExtensionService (CSREES), to initiate an interregional research project to coordinate re-search activities within the agricultural community to obtain registrations for mi-nor use needs This project, which has become known as the IR-4 Project, wasestablished in 1963 and encompasses the following objectives:

To obtain minor and specialty use pesticide clearances and assist in themaintenance of current registrations

To further the development and registration of microbial and specific chemical materials for use in pest management systems

bio-Administered by CSREES and funded by both CSREES and the tural Research Service (ARS) and with the cooperation of state land grant institu-tions, the agricultural chemical industry, the USEPA, and commodity organiza-tions, IR-4 is the only public research program in the United States created toassist with the registration of pest control agents for minor uses.Figure 1showsthe relationships among the elements of IR-4

Agricul-The role of the IR-4 Project is that of expanding existing pesticide productlabels to include minor crop uses In order to do this, IR-4 gathers information

on pest management needs for minor crops, including fruits, vegetables, and mentals; develops priorities to address the most important uses first; coordinatesand funds both field and laboratory research among state and federal scientists;and prepares and submits appropriate tolerance and registrant documents to theUSEPA All research conducted by IR-4 on food crops is compliant with goodlaboratory practice (GLP) IR-4 works cooperatively with pesticide registrants inorder to access, by letter of authorization, the basic registration information used

orna-to support major crop registration To accomplish this task, IR-4 interacts withthe crop producers to ensure that research and registration programs are relevant

to current needs, with the USEPA to ensure that there are no major impedimentsthat could unduly delay registrations, and with the agricultural chemicals industry

to ensure that the intended uses will be commercially registered and offered forsale

F IGURE 1 Relationships of the various entities in the IR-4 program.

The IR-4 is justifiably proud of its accomplishments in assisting minor cropproducers with registration needs As shown in Table 1, IR-4 has contributedsignificantly to food and ornamental pesticide clearances and to the advancement

of registrations for biological pest control materials IR-4 also has met the lenges of FIFRA-88 by supporting minor use registrations that would have other-

chal-T ABLE 1 Progress of the IR-4 Project

Project accomplishment—pesticide clearances 1963–1998

4745 food crop clearances

5142 ornamental clearances

107 biopesticide clearances

FIFRA 88 responses

Reregistered 700 minor uses on food crops

Reregistered over 2000 ornamental uses

Obtained 10 biopesticide tolerance exemptions on 56 crops

FQPA responses

1997: 45 reduced risk studies out of 150 total studies

1998: 78 reduced risk studies out of 163 total studies

1999: 82 reduced risk studies out of 139 total studies

Source: Ref 22.

wise been lost in the reregistration process and the FQPA by focusing its researchefforts and the registration of pesticides classified by the USEPA as reduced riskproducts In fact, nearly 45% of all recent pesticide research projects sponsored

by the IR-4 averaged over a 3 year period involve reduced risk pesticides.Because research for the purpose of establishing the registration of a pestcontrol product is generally beyond the purview of state and federal agriculturalscientists as well as most commodities-based organizations, there is abundantopportunity for these segments of the agricultural community to interact withthe IR-4 Project to identify needs and participate in the research process withsupplemental funds available from the IR-4 More often, research carried out bystate agricultural experiment station and federal research scientists forms the basis

of new and innovative pest management systems and techniques that benefit nor crop producers Information developed by these scientists often applies di-rectly to nonchemical control methods that may supplement or in some instancesreplace traditional pesticide-based control measures or that may identify inte-grated pest management strategies that require the new registration of a pesticide

mi-or biologically based product to achieve implementation In such instances, publicand private sector scientists work closely together with the IR-4 to respond tothese research needs

The issue of pest management on minor crops is not limited to the UnitedStates The Federal Republic of Germany convened a symposium in 1993 tostudy the issue of expanded pesticide labeling to include off-label crops and toexplore ways to harmonize the use of pesticides among the European Communitynations A discussion of the need for expanded pesticide labeling for pesticides

on minor crops was included in a pesticide residue workshop in Tokyo in 1996

In addition, the Canadian government established a minor use program that worksclosely with the USDA’s minor use program These countries, together with Mex-ico, are concerned with the need for properly labeled safe and effective pesticidesfor use on low volume crops or for the occasional use on major crops where pestoutbreaks are sporadic or geographically limited

Through the USDA’s IR-4 Minor Use Program, the United States hasjoined efforts with Germany’s Federal Biological Research Centre for Agricultureand Forestry and with the Canadian minor use program to sponsor research pro-grams and share research information on projects of mutual interest Testing pro-tocols and good laboratory practice compliance procedures have been imple-mented to enable the exchange and use of data by the respective regulatoryagencies There are presently about 20 cooperative projects under way with theCanadian government and several additional research projects involving Ger-many and Mexico Data resulting from these trials will be combined and used

by the respective countries to support new pesticide labels

Pest management on minor crops is clearly a global problem Althoughdifferent countries are approaching the issue in varying ways, the growing trend

toward international cooperation will hasten the registration of newer and saferpest control products for a variety of minor crops while benefiting growers byreducing the associated research and development costs This approach will likelyexpand to include partnerships with the agricultural chemicals industry as theavailability of reduced risk products increases.

2 IMPORTANCE OF ECONOMIC LOSSES

Crops and livestock are attacked by about 50,000 species of fungi that causemore than 1500 diseases About 15,000 species of nematodes attack crop plants,and more than 1500 of these cause serious damage More than 10,000 species

of insect pests cause losses to crops, livestock, forests, structures, and storedproducts About 600 species of insects cause heavy losses to crops each year.About 30,000 species of weeds compete with crops, and about 1800 of thesecause serious losses each year Losses caused by insects, plant pathogens, nema-todes, and weeds continue to reduce the maximum potential yield of crops grownthroughout the world In the United States, preharvest losses to pests have beenestimated at about 37%, with insects accounting for 13% of the losses and plantpathogens and weeds each accounting for 12% Postharvest losses to pests areestimated to be about 9% These losses occur despite the fact that good agricul-tural practices with pest control technologies are followed [4]

Research on pests is a very important component of the budgets of theuniversities, SAES, and the USDA In 1997, federal funds from the USDA andfederal plus non-federal funds were about $174 million and $407 million, respec-tively, to support research on pests [5] Table 2 indicates the distribution of thesefunds

Justification for expenditures of research dollars in the public and privatesectors on pests and their control is based in part on losses caused by pests,acreage of the crop grown, and the extent of pesticide use To some extent, themagnitudes of pest losses also influence what studies an investigator will under-take and the ability to obtain increases in research budgets

T ABLE 2 Allocation of Federal Funds in Fiscal Year

1997 to Pest Control Research

Funds ($million)

Control of fruit and vegetable pests 80.5 185.8

Estimates of crop losses can also assist in determining the constraints incrop production that may be overcome by the application of more expensivetechnologies in integrated pest management (IPM) programs Some of these tech-nologies may require considerable research and development expenditures beforethey are ready for commercialization Loss estimates are useful in estimating theeffects of pest density on yield These data are most often used to construct equa-tions or mathematical models to predict losses for various pest densities Thisinformation can then be used in the decision-making process of when or whennot to apply measures to reduce the pest population density to avoid an economicloss and is useful in the development of pest management programs An economicloss is defined here as the production value of the estimated loss of the commodity

as a result of a pest infestation These data help provide some insight as to thecapacity of the pest to cause a loss and the conditions under which that lossoccurs They also can serve as a gauge to measure the effectiveness of differentpest control measures

Crop losses are not the major driving force behind the decisions of pesticidemanufacturers to develop and label new pesticides or expand the labels of existingpesticides These decisions are based primarily on the market size, which is gov-erned by the acreage of the crop grown, the number of pesticide applications tocontrol the pest, and crop liability in the case of product failure or crop destruc-tion Pesticide manufacturers generally target their products for the major cropssuch as corn, cotton, soybeans, and wheat These four crops were planted to 213million acres in 1998, which accounted for about 68% of the total cropland har-vested for food and feed crops in the United States, whereas commercial acreage

of fruits and vegetables was about 7 million acres Development of data to registerminor uses is generally left up to publicly funded programs such as the IR-4program in the United States and similar programs in Canada and Germany.The basic philosophy of managing pests to prevent or reduce losses is dif-ferent for each of the major categories of pests With few exceptions, the wayweeds cause major losses in crops is by interference [6] This includes weedcompetition with the crop for environmental factors contributing to plant growthsuch as light, moisture, and nutrients Allelopathy plays a role in some species

of weeds Therefore, the major strategy to prevent losses from weeds has been toeliminate the weeds from the crop environment by either mechanical or chemicalmethods or a combination of the two More recently, genetic engineering hascome to play a significant role in weed control for the major crops through theintroduction of herbicide-resistant genes Sethoxydim, glyphosate, and glufosi-nate-ammonium are some of the herbicides used with transgenic crops such ascotton, corn, and soybeans Approximately one-third of U.S soybean acreagewas planted to the Roundup Ready variety in 1998 The future trend will be tohave more acreage planted to transgenic plants in the major crops for weed con-

trol However, public resistance to this new technology may delay its application

on a large scale for the minor use food crops

Diseases, insects, and nematodes, on the other hand, are dependent on thehost plant at some stage in their life cycles These pests cause losses that can beattributed to a parasitic relationship For the most part, these organisms are held

in check by biotic factors It is only when pest outbreaks occur or are likely tooccur that pest control measures are applied There are times, particularly in thecase of insects, when pest control measures cause outbreaks of other pests The

insect pathogen Bacillus thuringiensis was introduced into corn, cotton, and

pota-toes in 1995 and 1996 and offers an effective way of controlling lepidopterouspests with minimum disruption to beneficial insects The predominant method toprevent disease and nematode losses has been and continues to be the use ofresistant cultivars and the treatment of seed with fungicides, with the use of fungi-cides and nematicides as preventive or curative measures

The per-acre value of the crop is an important consideration when methods

to control pests to reduce losses are considered Vegetables, fruits, and nuts areworth about 3.5–16-fold more in value per acre than cotton, corn, soybeans andwheat (See Table 3.)

It is worthy of note that losses to minor crops represent a much greatervalue than do losses to major crops at the same percentage reduction in yield.This most likely influences the degree of acceptance of losses and the extent towhich control measures are applied to prevent or reduce losses It also influences

to some extent the crops that pesticide registrants will add to their labels because

of the liability incurred if crop damage or product failure occurs

The USDA National Agricultural Statistics Service (NASS) periodicallyconducts surveys to determine pesticide usage on various commodities Theirsurveys conducted in 1996 and 1997 for vegetables and fruits, respectively, showthat a high percentage of acres is treated for most of these crops (Appendixes 4

T ABLE 3 Crop Value per Acre, 1996–1998

Production value Acres

and 5) On average, insecticide acreages are the highest, herbicides next, followed

by fungicides The percentage of acres treated ranges from 52% to 72% for tables and from 75% to 77% for fruits Multiple applications of insecticides andfungicides are generally used to maintain the quality that the U.S consumer isused to and expects in the marketplace and to meet the marketing standards ofthe Agricultural Marketing Service (AMS) and USDA and Food and Drug Ad-ministration standards for pest parts in processed foods

vege-In the United States, there has been no attempt to develop comprehensivenational data on losses for all pest classes since the publication of the USDAhandbooks on losses in 1951 [7] and 1965 [8] The Weed Science Society con-ducted a survey in 1979 on the percentage average annual losses due to weedsfor 64 crops [9] Their data suggest that loss of potential production can range

as high as 20% for fruits and vegetables Sometimes losses can be so severe thatgrowers are compensated by the Farm Service Agency of the USDA For in-stance, in 1996 and 1997 growers were paid about $9 million each year for lossesdue to Kamal bunt fungus [10]

In 1988, an extensive survey was conducted in North Carolina to estimatelosses caused by plant diseases and nematodes [11] Losses for the vegetablesand fruits and nuts categories were estimated at 24.7% and 22.8%, respectively,while losses for field crops were estimated at 14.9% Overall, the losses to crops

in North Carolina attributed to diseases and nematodes in 1988 were $500.1 lion for crops valued at $3.3 billion These losses accounted for 15% of the eco-nomic value of the crops For vegetables and fruits and nuts, the economic losseswere much higher, representing 32.7% and 29.5%, respectively

mil-The following provides specific information on pest losses as compiled andreported by the Pesticide Impact Assessment Program (PIAP) and reported intheir Crop Profiles page on the Web

According to the crop profile for walnuts [12], California produces 99%

of the walnuts grown in the United States on approximately 177,000 acres duction averages about 235,000 tons/year and was valued at $314 million in

Pro-1995 Approximately 60% of the acreage is susceptible to damage by the codlingmoth and requires from one to three treatments per year If uncontrolled, damagecan exceed 40% Other pests of walnuts grown in California and the potentialfor damage are listed inTable 4

Mushrooms are Pennsylvania’s largest cash crop, with a farm gate value

of $272 million in 1996, and account for 45% of the nation’s total production[13] Scarid fly larvae can limit the yield of mushrooms by as much as 70%,whereas Phorid flies cause crop losses as vectors of certain mushroom pathogens.Losses from viral epidemics can range from 10% to 100% Bacterial blotch,which causes a discoloration of the mushroom cap, reduces the crop value by30–80% Fungal diseases also take their toll of mushroom yields Trichodermagreen mold currently causes losses of 5–10%, but when it was at its worst it

T ABLE 4 Insect and Disease Pests of Walnuts

Insect

Mites (two-spotted, European red, Pacific) 25

Soft scales, frosted, European fruit Lecanium 10

a Weeds cause serious problems in walnut production, but no percent loss was vided.

pro-caused losses of 20–80% Verticilium spot and dry bubble routinely cause croplosses between 15% and 60%, at times reaching 100%

3 PEST MANAGEMENT STRATEGIES FOR MINOR CROPS

A great deal of concern has been expressed over the past decade about the fects of federal pesticide legislation on the continued ability of minor crop farm-ers to produce quality products Initially, the 1988 amendment to FIFRA fo-cused attention on the vulnerability of the minor crop industry to an inadequatesupply of safe and effective pest control products National surveys and work-shops conducted by the IR-4 Minor Use Program in 1989 suggested that about

ef-1000 minor use registrations important to the agricultural community would belost because of the economics associated with the cost of reregistration for mi-nor crops [14]

Losses of pest control agents of this magnitude in the minor use market,together with associated losses in the major crop market, were forecast as havingsignificant effects on U.S agricultural production The most profound of thesewould be a substantial increase in the cost of foods, which would result in thegreatest hardship being borne by the lower income population Along with in-

creased costs there would be decreased quality of produce When coupled, thesefactors would lead to reduced consumption of U.S produce with a concomitantincrease of imported foods Fortunately, IR-4 researchers, with additional fundingprovided by Congress and with the help and cooperation of state and federalresearchers, private industry, and commodity producers, were able to present data

to defend about 700 of the most important minor crop reregistrations

The 1996 Food Quality Protection Act (FQPA) presented additional andmore complex challenges to the minor crop industry In addition to establishingnew standards to protect the health of the public in general and that of infantsand children in particular, the act also contains provisions that will encourageprivate sector registrations for minor crops These provisions will likely focusincreased commercial interest on minor use clearance needs Nevertheless, thereassessment of upward of 10,000 tolerances by 2006 will result either in certainuses being voluntarily canceled or in the USEPA mandating additional exposuredata This will increase the cost to registrants to maintain these registrations,which will be passed on to the consumer in the form of higher costs for freshfruits and vegetables Moreover, because minor crops utilize a disproportionatelygreater percentage of the risk cup,* the economic disincentive inherent to minoruses will be further exacerbated It is clear that many, if not all, of the nearly

400 minor crops grown in the United States will be affected and will requireeither additional data to support registration of pesticides for minor crops or theregistration of new lower risk pest management alternatives

It is likely that the “green” industry will be similarly affected by FQPA.Any decisions resulting in the decreased availability of pest control products forfood crops will affect the availability of products that are registered for applica-tion on nursery, floral, and forestry crops and turf grass Conversely, new saferpest control products developed for use for the major crop market will, in alllikelihood, be available for use on nursery, floral, and turf crops

Clearly, some of the older pesticide products will be lost to the minor cropmarket Fortunately, many new products have been or will be introduced thatwill provide effective and environmentally safe pest management One of theprovisions of the FQPA is that of mandating the USEPA to expedite the review

of “safer” or reduced risk pesticides The law requires that the USEPA developcriteria and procedures for expediting the consideration of applications for saferpesticide products that will enhance public health and environmental protection,thus helping them to reach the marketplace more rapidly as replacements forolder and potentially riskier chemicals

* The USEPA establishes the total level of acceptable risk from the lifetime exposure for each cide, which is represented by the pesticide’s population-adjusted dose This is commonly known as the “risk cup.”

pesti-Expedited review is clearly a powerful incentive that has encouraged theagricultural chemicals industry to explore new and safer pesticide chemistriesand will continue to do so Although these efforts will focus primarily on themajor crops, minor crop producers will also benefit.

In 1997 the IR-4 Project adopted a risk reduction strategy to accelerate theregistration of new pest control products for both minor food and ornamentalcommodities This strategy promised to

1 Promote reduced risk pest management for minor crops

2 Develop risk mitigation measures for existing pesticide registrations

3 Assist with the registration of biologically based pest control productsfor minor crops

4 Register and maintain pesticides essential to IPM systems

Utilizing established partnerships with agricultural chemical companies andcrop producer organizations, IR-4 is moving forward rapidly to target productsthat are eligible for the USEPA’s Reduced Risk classification In 1999, over 60%

of IR-4 food use research was focused on reduced risk pesticide chemistry, withthe goal of 21/2years from project initiation to the submission of the tolerancepetition to the USEPA To further expedite the search for safe and efficaciousproducts, it is likely that IR-4 will need to expand its research program beyond itstraditional objective of GLP-compliant residue testing to non-GLP performanceevaluations to assess the value of new products for specific minor (and, particu-larly, ultraminor) crop pest management needs

Working closely with product managers at the agricultural chemical panies, IR-4 has developed and continually updates a list of new products andrecent introductions that may be useful to minor crop producers A discussion

com-of these products is presented to state and federal research scientists, extensionpersonnel, and crop producers at annual minor use workshops in order to elicitbroad-spectrum input into the usefulness of the products

Some newer products that may be beneficial for minor crop pest controlare listed inTable 5.It is important that all producers of minor crops becomeaware of the registration status of pesticide products used in their pest manage-ment programs by contacting state agricultural extension service and pesticidemanufacturer representatives Although registration objectives are generally di-rected toward the more lucrative large volume crops, pesticide manufacturers aremore aware of the minor crop market than in the past and are more likely to directdevelopmental research efforts in this direction The IR-4 Minor Use Program can

be of significant value in assisting with the registration of new products Because

it generally requires 3–5 years from initiation of research to labeling, it is tant that minor crop producers initiate early clearance requests through their stateIR-4 representative

impor-T ABLE 5 Pest Management Products with Potential for Use on Minor Crops

leaf-miners

quisqualis

gicide

larvae

various strains

and stomach poison

and perennial weed control

Emanamectin Proclaim, Strategy Novartis I Controls larval lepidop- IPM potential

temic insecticide

gicide

liar disease control tential

control of broadleaf weeds, nutsedge

tain bacterial and gal disease

against many insects

annual grasses, leaf weeds

broad-T ABLE 5 Continued

mites

replacement

po-tential

verncaria

leaf weed control

many crops

Potassium bicarbonate Armicarb, Kaligreen Church & Dwight F Powdery mildew Biopesticide

tive properties

leaf weed control

ous insect mites