• TABLE OF CONTENTS
HIDE
 Introduction
 Crop background
 Past research emphasis: world...
 CIAT strategy
 CRSP strategy
 The principle of complimentary
 Achievements in research and...
 Need to revaluate research...
 Future research needs
 Conclusion
 Reference






Title: Strategies, achievements and challenges in bean research: the CIAT perspective
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Title: Strategies, achievements and challenges in bean research: the CIAT perspective
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Language: English
Creator: van Schoonhoven, A.
Publication Date: 1978?
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Farm life   ( lcsh )
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Table of Contents
    Introduction
        Page 1
    Crop background
        Page 1
        Page 2
    Past research emphasis: world wide
        Page 3
    CIAT strategy
        Page 4
    CRSP strategy
        Page 5
    The principle of complimentary
        Page 5
        Page 6
    Achievements in research and training
        Page 7
        Page 8
        Page 9
    Need to revaluate research strategies
        Page 10
        Page 11
    Future research needs
        Page 12
        Page 13
        Page 14
        Page 15
    Conclusion
        Page 16
        Page 17
    Reference
        Page 18
        Page 19
Full Text






STRATEGIES, ACHIEVEMENTS AND CHALLENGES IN BEAN RESEARCH;

THE CIAT PERSPECTIVE



A. v. Schoonhoven*



Introduction



National and international bean research programs have been engaged in

past years in developing improved common bean varieties and production

practices. Considerable progress has been made in certain research areas,

yet, despite concerted efforts, progress is lacking in others. This paper

briefly highlights past research strategies, including major achievements, or

lack thereof and proposes some strategic changes to meet future challenges.

Since research, done by CIAT and the CRSP greatly influences national programs

in developing countries, a periodic and critical evaluation of these

international efforts, and how they relate to each other, is highly

appropriate.



Crop Background



Dry beans, Phaseolus vulgaris L., originating in the medium elevation

mountain ranges of Meso-America and South America, were distributed worldwide

by early colonizers.


* Leader Bean Program. CIAT, A.A. 6713; Call, Colombia.










STRATEGIES, ACHIEVEMENTS AND CHALLENGES IN BEAN RESEARCH;

THE CIAT PERSPECTIVE



A. v. Schoonhoven*



Introduction



National and international bean research programs have been engaged in

past years in developing improved common bean varieties and production

practices. Considerable progress has been made in certain research areas,

yet, despite concerted efforts, progress is lacking in others. This paper

briefly highlights past research strategies, including major achievements, or

lack thereof and proposes some strategic changes to meet future challenges.

Since research, done by CIAT and the CRSP greatly influences national programs

in developing countries, a periodic and critical evaluation of these

international efforts, and how they relate to each other, is highly

appropriate.



Crop Background



Dry beans, Phaseolus vulgaris L., originating in the medium elevation

mountain ranges of Meso-America and South America, were distributed worldwide

by early colonizers.


* Leader Bean Program. CIAT, A.A. 6713; Call, Colombia.









Current annual bean production in the tropics amounts to about 4 million

tons in the New World, 1.5 million tons in Central Africa and about 0.3

million tons in West Asia, and North Africa. Total production has increased

over the last years, but this increase was mostly due to area increases.

Beans have been increasingly forced to more marginal agricultural land, to

make room for more profitable crops.



Beans are an important subsistence and cash crop, especially in rural

areas. Per capital bean consumption is highest in Rwanda and Burundi (about 40

kg/person/year), and is about half that rate for the two leading producers in

the Americas, Brazil and Mexico. In Rwanda and Burundi one third of total

protein intake is from beans. In the tropics, consumption of green or snap

beans is substantial. Bean leaves are also consumed in Africa.



Most beans are produced by small farmers, many of whom are women, and who

are often unable or unwilling to use inputs to increase production.

Typically, beans are produced in association with other crops, mostly maize,

and in many different production systems. Beans are also attacked by a large

number of pathogens, many of which are seed-borne. These factors keep

productivity low, at around 550 kg/ha, although total crop return per hectare

is higher. Bean monoculture equivalent yield in the tropics is estimated at

around 800 kg/ha. Beans are also produced in monoculture under high input

conditions, mostly in coastal Mexico, Chile, and Argentina, where yields are

relatively high. In Chile, yields average around It/ha, but in some years

they have gone as high as 1300 kg/ha (FAO Production Yearbooks).










PAST RESEARCH EMPHASIS: WORLD WIDE



Bean production constraints are numerous; nevertheless it is generally

agreed that diseases and insects are the most destructive. Drought and

infertile soils rank high, too. The bean literature, in CIAT's world-wide

bean documentation centre reflects this hierarchy. Of the 6798 bean documents

(published papers, research reports, etc.) processed to date, 1629, or 24.0%,

are concerned with diseases. Agronomy publications make up the second most

important research area, covering 1444 or 21.2% of all articles. Genetic

improvement, in third place, covers 637 or (9.3%) of the articles. Articles

referring to bean research for human consumption trail far behind with 254

documents (3.7%). Of the articles on genetic improvement, 34.6% involve

breeding for disease and insect resistance. About 27.1% of all breeding

articles involve yield breeding; which means, only 2.5% of all documents in

CIAT's documentation centre discuss yield breeding!



The emphasis on breeding for disease resistance is probably stronger than

the statistics indicate. In the past, much effort was directed towards

breeding early maturing varieties. Early maturity would shorten the crop's

exposure to diseases and insect pests. Admittedly, there were other reasons

for developing early maturing varieties, including: to fit beans into a crop

rotation cycle, or climate cycle; to catch the early market high prices; or to

provide food as early as possible after the dry season.









CIAT STRATEGY



From its formation in 1973 CIAT's Bean Program has placed most emphasis

on breeding for tolerance to stress, principally disease resistance. Surveys

justified this emphasis. Two studies support this conclusion: a survey in

Colombia in 1974-75 identified diseases and pests as the main production

constraints both of small and large farmers (Ruiz de Londoio et al, 1978). A

second study of a large on-farm project to improve maize and bean yields in

Honduras (PROMYF) concluded that the use of fertilizer or other inputs was too

risky until a more disease-resistant bean variety became available.



The CIAT Long Range Plan, (CTAT 1981), gave highest priority to disease

control research. At the beginning of the 80's, about 80% of CIAT's total

crosses involved disease resistance. In 1984, for example, the CIAT Bean

Program made 4163 new hybrid combinations. Of these, 79% were made to obtain

multiple disease or insect resistance, to improve grain type, or to create

levels of variation not found in the gene bank. Over one third of these

crosses were done to obtain higher levels of disease resistance; only 12.5%

were specifically intended to improve yield potential and architecture. The

basis of the priority to develop disease resistant varieties was: the

small-farmer nature of the crop; the widespread importance of diseases; the

fact that most diseases are seed-borne and persist because farmers usually

save their own seed; and due to the difficulty to control diseases by any

means other than by genetic resistance. Throughout the 1970s, CIAT's bean

breeding efforts concentrated on controlling diseases through the development

of multiple- disease resistant varieties. Priorities were given to Bean

Common Mosaic Virus (BCMV), Rust, Common Bacterial Blight (CBB), Anthracnose










and Angular Leaf Spot. We believed that a multiple disease resistant

variety would reduce production costs, especially production risk, and

stimulate farmers to further increase yields through increased inputs.



CRSP STRATEGY



The Bean/Cowpea CRSP was formed to support research on these two basic

foodcrops in the developing world. Of the 18 projects which form the global

plan of this CRSP, 12 involve dry beans. Five of the bean projects (42%) are

specifically devoted to the development of disease resistance.



In the 1984 CRSP Annual Report, 151 articles, reports or presentations

are listed of which 30% discuss bean diseases and pests, and only 2% yield

potential. Clearly the CRSP, like CIAT, is strongly biased towards pest and

disease control through genetic resistance.



THE PRINCIPLE OF COMPLEMENTARITY



Bean research is sometimes divided into two broad categories: character

improvement and character recombination. The former is the development of

parental material with a high level of disease resistance, yielding ability,

etc. The latter, in the form of commercial varieties, combines this superior

germplasm with agronomic and consumer requirements. While character

improvement mostly involves basic research, character recombination (or

character deployment) is mainly applied research.










and Angular Leaf Spot. We believed that a multiple disease resistant

variety would reduce production costs, especially production risk, and

stimulate farmers to further increase yields through increased inputs.



CRSP STRATEGY



The Bean/Cowpea CRSP was formed to support research on these two basic

foodcrops in the developing world. Of the 18 projects which form the global

plan of this CRSP, 12 involve dry beans. Five of the bean projects (42%) are

specifically devoted to the development of disease resistance.



In the 1984 CRSP Annual Report, 151 articles, reports or presentations

are listed of which 30% discuss bean diseases and pests, and only 2% yield

potential. Clearly the CRSP, like CIAT, is strongly biased towards pest and

disease control through genetic resistance.



THE PRINCIPLE OF COMPLEMENTARITY



Bean research is sometimes divided into two broad categories: character

improvement and character recombination. The former is the development of

parental material with a high level of disease resistance, yielding ability,

etc. The latter, in the form of commercial varieties, combines this superior

germplasm with agronomic and consumer requirements. While character

improvement mostly involves basic research, character recombination (or

character deployment) is mainly applied research.









CIAT's Bean Program emphasizes applied research (character

recombination). It adapts the developed world's knowledge about bean growing

to the tropics, and combines it with the best knowledge found in the bean

producing countries. Obstacles encountered in the research process are often

solved by seeking help from basic research institutes, such as universities in

the developed world and in the tropics. This form of applied bean research

concentrates on the development of improved germplasm, and its accompanying

agronomy promoted to farmers through national programs. CTAT training

programs for national research program personnel help the latter develop and

promote new technology to farmers.



CIAT recognizes the CRSP as an association between US universities and

developing countries designed to improve food production. The CRSPs are

mainly concentrated in universities where the principle orientation is towards

basic research (character development). Progress in basic research allows

more rapid progress in the area of applied research, such as is conducted

mainly by the national programs and CIAT.



CIAT and the CRSP are largely complimentary. The Memorandum of

understanding signed by both institutions spell this out clearly.

Nevertheless, if either program, CIAT or the CRSP, would deviate from the

sphere of its comparative advantage (CIAT concentrating on basic research or

the CRSP being over-involved in varietal development and promotion)

duplication and waste of resources would result.



USAID has reserved a small IARC-targeted budget for Special Constraints

Research by US institutions. This program precisely fits the principle of










'comparative advantage'. US universities geared toward basic research would

be financed to resolve bottlenecks IARC's encounter in their applied research

programs. Applying the comparative advantage principle, this new AID

initiative would well fit within the CRSP crop mandate.



The establishment of research ties between US universities and CIAT is

difficult due to restrictions on the use of US federal funds to travel to

Colombia. Such has not been the case with European agricultural research

centres which have increased their Bean Program support through several

collaborative basic research projects.



In summary, at CIAT we believe that the CRSP and its sponsors should

recognize that the goal of improved nutrition requires both basic and applied

research. Efforts to make the CRSP projects impact directly on national

program production are understandable and humane but, nevertheless, they may

prove duplicative and should not be encouraged. Similarly, CIAT should not

enter the area of basic research, unless no solutions are available from

outside.



ACHIEVEMENTS IN RESEARCH AND TRAINING



Progress in research and training over the last decades has been

impressive. This is specially so when we take into consideration the

relatively small body of researchers investigating beans or cowpeas, as

compared to crops such as maize, wheat or soybeans.









1. Over the past 10 years CIAT's training has created a strong research

capability in the national programs to control diseases through

resistance breeding, and to a lesser extent through integrated disease

control. Of 572 national program scientists trained at CIAT from 1973

until now, 159 (27.8%) were trained in pathology (excluding production

training). Those trained in breeding were mostly involved in breeding

for disease resistance and, if included, would raise the percentage of

scientists trained in disease control to 50.4%.



2. The six CRSP projects and CIAT, both involved in disease resistance

breeding, have strengthened university and national program potential

to control diseases. The CRSP-sponsored degree training is highly

beneficial and is most appreciated at the national program level. This

training will have a continuing positive effect on future research.



3. Significant progress has been made in the development of multiple disease

resistant germplasm. Since 1979, most CIAT coded lines are BCMV

resistant. The race variability and inheritance of resistance is well

understood, enabling US and CIAT bean researchers to resolve the problems

of necrotic strains in the USA, and deal with blackroot in Africa in a

relatively short time. Anthracnose resistance is abundantly available;

pathogenic variation has been studied and many new races have been

identified, and bean genotypes with wide resistance are available. There

is no evidence that the fungus has formed new races, overcoming

resistance sources. New resistance sources to common bacterial blight

(CBB) have been identified from crosses made by CRSP scientists between

P. vulgaris and P. acutifolius. Screening methods for CBB are well










developed, and additional resistant parents have been identified.

Angular leafspot, though, is one of the least researched major bean

pathogens. Recent research has clarified the pathogen's race

distribution and resistant germplasm has been identified for different

bean producing regions. The International Bean Rust Nursery has

identified many sources of germplasm with ample and more stable

resistance. The small rust pustule type, characteristic of some bean

accessions, is especially promising, as it influences yield less than the

large pustule present on susceptible varieties. A standard evaluation

scale for rust has been established. Many examples of research progress

can be cited for other bean diseases and pests. Such as: upright

architecture to avoid whitemold; integrated web blight control strategy;

new sources of non race specific resistance to the halo blight pathogen;

etc. Numerous other examples could be mentioned to highlight the

impressive research progress that has been made to control bean diseases

through varietal resistance.



4. Research on insect resistance, drought tolerance and nitrogen fixation,

despite limited efforts, has made considerable progress. Resistance to

seed-infesting bruchids has been found in wild, uncultivated forms and is

being incorporated in commercial cultivars. Bean pod weevil and Mexican

Bean Beetle resistance has been identified and used in crosses. Drought

tolerance identified so far in beans seems to be mainly related to the

ability of bean genotypes to root deeply. The ability to fix atmospheric

nitrogen was transferred from tropical germplasm into temperate material.










5. Many national programs 1ave released disease resistant germplasm.

Guatemala has greatly increased production and productivity with BGMV

tolerant varieties; self-sufficiency in beans has been achieved and

prices are down. In 1984, Argentina's -net production increased US$2.1

million by planting new BCMVl anthracnose and BCLMV resistant varieties.

Costa Rica may have reached self-sufficiency in beans through the use of

multiple disease-resistant varieties. Cuba released ICA-Pijao, which is

resistant to BCMV and BGMV. Other examples could be cited where disease

resistant varieties have had an impact on production. However, it is too

soon for FAO statistics to reflect those achievements.



6. Many more research achievements, some probably even more important than

the ones listed, could be cited. It is obvious that a grLat deal of

research progress has been made over the past years.



NEED TO REEVALUATE RESEARCH STRATEGIES



In the past 45 years, research in the US has doubled or tripled yields of

such crops as wheat, soybeans, maize and sorghum. Soybean breeding over the

last 75 years has increased yields through new varieties by 47%, or a yield

gain of 18.8 kg per year through genetic improvement alone (Burton, 1981;

Specht and Williams, 1984). A significant proportion of this yield increase

resulted from hybridization in the mid fourties after widening the genetic

base (Specht and Williams, 1984), despite the problem of photoperiod

sensitivity in soybean germplasm. In another legume, peanuts, yields went up

4.6 fold in 25 years of research in Georgia (from both improved varieties and

agronomic practices). However, in the last 45 years of research in the US,









only a very modest dry bean yield increase was achieved. (FAO, Production

Yearbooks; Fig. 1).



While great progress has been made in bean research, it is generally not

reflected in increased yields in the USA or in the tropics. The reasons for

this are diverse. Disease resistance may have been overcome by new pathotypes

(e.g., for rust) or by the introduction of new strains (e.g., BCMV blackrot

into the USA). Earliness is associated with reduced yield potential, and

beans, especially in the tropics, have been moved to more marginal land. Past

research may have stabilized yields, but one firm conclusion can be drawn:

this research did not increase bean yields significantly.



CIAT's ten years of genetically improving beans has made substantial

progress in breeding for disease resistance, upright architecture, insect

resistance, etc. A significant increase in production has been made in

several countries. However, in the IBYAN and other yield trials, the best

black seeded CIAT lines show no higher potential for yield than elite bean

varieties such as ICA Pijao or Jamapa, superior varieties developed by

national programs before CIAT's formation (Table 1). Similarly, Brazil's

leading cream striped variety, Carioca, still ranks among the top yielders in

most yield trials. During years of little disease pressure, or in high yield

areas, CIAT developed germplasm does not offer a yield advantage over

traditional varieties (Table 1). However, during wet, disease intensive

years, CIAT lines outperform local checks. We realized, therefore, that a

change in research strategy was called for by placing greater emphasis on

yield potential, as spelled out in our Medium-Term Plan (CIAT, 1985).









The decision to plant beans depends on the advantage a farmer expects

from them over other crops. If we o y include legumes as alternatives,

significant research progress in those 'legumes will affect the competitive

advantage of beans. In chickpeas, far example, new, upright, late maturing,

high yielding, Ascochyta leaf blight-resistant varieties will form a very

attractive alternative in many areas where both crops are grown (see ICARDA

Annual Reports). Other examples could be cited, where the lack of research

progress relative to other crops, has resulted in loosing ground.



It is, therefore, time to critically rethink bean research strategies.

We at CIAT have concluded that the following three areas will need increased

attention:

/



FUTURE RESEARCH NEEDS



1. Yield Potential. Initially, yield potential needs to be increased in

irrigated areas where diseases and other stresses play an insignificant

role. Next in areas where farmers have adopted disease resistant

varieties. Yield potential is related to disease resistance breeding.

If two varieties with equal levels of disease resistance are subjected to

the same level of disease pressure, then the one with the highest yield

potential will yield most. We assume that the biological mechanism

causing the disease resistance does not reduce yield. In addition,

research on other crops has created an increasing need to raise the yield

potential of beans. Neither research in the US, nor at CIAT has

identified the factors that could increase bean yield. Methods to raise









bean yielding ability are simply not available at this time. It is,

therefore, my firm belief that the principal factor which will determine

beans place among world crops in the future will be based on whether or

not their yield potential under stress conditions can be raised.

Research, however, should start with raising yields under no-stress

conditions.



2. Adaptation of Tropical Germplasm. Beans originated in the tropics. The

inability of tropical germplasm to adapt to higher latitudes has hindered

US and European breeders from utilizing the full broad genetic

variability. This is illustrated by a statement of the National

Academy of Science (1972); ... "that, for a considerable part of the

edible dry bean acreage in the United States, annual production rests

upon a dangerously small germplasm base" (page 225). A similar

statement is made about snap beans. Only recently have US breeders tried

to broaden the genetic base of their breeding programs. While this will

provide the means to achieve increased yield potential, change in

architecture, (e.g., the use of NEP-2) etc., it will require long-term

research efforts to fully utilize tropical germplasm, as the mechanisms

and inheritance of adaptation are not well-understood. Increased

attention to these matters is now needed to meet future needs. The

difference in yield potential of small and large seeded types is a

related problem which also needs to be resolved. The problems involved

in adaptation research are the reason it has not been done more

vigorously in the past. Existing new germplasm stored in the CIAT gene

bank (which now comprises 35.000 accessions), or materials derived from

it, nearly always perform very poorly in the US or Europe. Sixty percent









of CIAT's germplasm is photoperiod sensitive and not adapted to the US.

Lack of understanding of the mechanisms and inheritance patterns of

photoperiod and temperature adaptation greatly delay breeding efforts and

hinder the addition of new variability to US breeding programs, thus

limiting progress. CIAT was not established to support the US dry beans

industry. Nevertheless, greater emphasis on research in this area could

provide enormous benefits to the US bean industry. It will also be

essential in improving the usefullness of CRSP projects, and in enhancing

the return of existing or improved germplasm to tropical countries. The

Cornell-Guatemala CRSP, for example, addressed these issues, by studying

the photoperiod by temperature interaction on bean adaptation. However,

it is too little and too early to benefit US breeders by offering methods

to fully explore the entire wealth of tropical genetic variability in

beans.



3. Digestibility and cooking time. Beans are a poor man's food. As income

increases, consumption increases, especially of preferred grain type; but

it declines again as income levels further increase. For example, in

Brazil, for the high income quartile of the population, the expenditure

elasticity for beans is estimated at 0.28, but for the lowest income

quartile at + 0.19 (CIAT, 1985). Wives participating in the job market,

the time it takes to prepare beans, the "heaviness" of the meal, all

contributed' to the decline in bean consumption in the industrialized

world. If the decline is to be prevented in the tropics and the human

diet to be based on a wide variety of plant species, including beans,

increased attention is needed to breeding for quality factors. Current

attention to those factors in the CRSP is probably adequate. Some shift









of emphasis may be needed in order to learn more about genetic

variability to better understand the magnitude of the environmental

component and the inheritance of quality factors. Reduced emphasis may

be given, at least initially, to the biochemical processes involved.

Only when this information is available can quality factors be successful

improved in breeding programs.



4. Disease Resistance. The emphasis on breeding for disease resistance

should be redirected to some degree. Major tropical production problems,

such as Bean Golden Mosaic Virus (BGMV) and Bean Yellow Mosaic Virus

(BYMV), are very poorly understood and are far more important than some

highly researched pathogens. Web blight, currently limiting the climate

range over which beans can be grown in the tropics, is hardly researched

at all. Universities have a clear advantage in providing the needed

basic information on such diseases.









CONCLUSION



The emphasis in bean research in the past has stressed trying to reduce

losses caused by diseases and pests. This strategy has, in general, not lead

to yield increases. Failure may have been partly due to the narrow genetic

base of most research programs. A change in research emphasis is, therefore,

proposed.



Future research should be greatly increased in three main areas: breeding

for increased yield potential; study of the photoperiod-temperature adaptation

of beans, particularly at higher latitudes to widen available genetic

variability; and, finally, to increase consumer acceptability of beans,

/especially urban consumers, by improving bean nutrition. I feel that

/ attention to yield potential is especially required among researchers in the

US and CIAT. However, the emphasis on breeding for disease resistance should

continue at the national program level, where many scientists have been

trained in this area. The CRSP and CIAT should narrow their disease

resistance breeding programs and focus on major, unresolved problems, such as

BGMV, web blight and, possibly, BYMV. New research emphasis should be funded

by shifting resources: In the case of the CRSP, by concentrating more on basic

research; and in the case of CIAT, by decentralizing research and supporting

the genetic improvement through well-trained national programs.











Table 1. Results of black IBYAN trial of 1982 in 7 locations where
yields were recorded above 3 t/ha and thus approach the
genetic potential of the species, and average over all 36
locations where the trial was planted.



Yield 7 best Yield over all
Variety/line locations 36 locations


Best CIAT bred line 3739


Jamapa 3412 1852


XAN 78 3298 1934


EMP 84 3256 1981


As above for IBYAN 1981 (4 and 22 sites respectively)


Best CIAT bred line 4004


Jamapa 3634 1723


BAT 804 3522 1852


BAT 873 3477 1850










REFERENCES


Bean/Cowpea Collaborative Research Support Program (CRSP). 1984.
Collaborative Research in the International Agricultural Research and
Development Network; a Case Study. Program Report, May 1984. 157 pp.


Burton, G. W. 1981. Meeting human needs through plant breeding: past
progress and prospects for the future. In: K. J. Frey (ed.) Plant
Breeding II, Plant Breeding Symposium, 2nd, Iowa State University,
1979: 433-466.


Centro Internacional de Agricultura Tropical (CIAT). 1985. Annual
Report 1984. Bean Program, 311 pp.


Centro Internacional de Agricultura Tropical in the 1980s. A long
range plan for the Centro Internacional de Agricultura Tropical.
1981. CIAT Series 12E-5, 177 pp.


Centro Internacional de Agricultura Tropical. 1985. CIAT in the
1980"s revisited. A medium-term plan for 1986-1980. 215 pp.


National Academy of Sciences. 1972. Genetic Vulnerability of Major
Crops. 307 pp.


Ruiz de Londoio, N., P. Pinstrup-Andersen, J. Sanders and M. Infante.
1978. Factores que limitan la productividad de frijol en Colombia.
CIAT, Series 06SB-2, 44 pp.


Specht, J. E. and J. H. Williams. 1984. Contribution of genetic
technology to soybean productivity retrospect and prospect. In: W.
R. Fehr (Ed.) Genetic contributions to yield gains of five major crop
plants. Proceedings Symposium, December 1981, Atlanta, Georgia, CSSA
Spec. Public. 7, 101 pp.














1600


1500



1400



1300




1200



I I I lI I I I I I I I I I I I I I I I
48/5252/56 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83
YEAR


Fig. 1 Dry bean yield trends in the United States.




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