Front Cover
 Title Page
 Table of Contents
 Sources of data
 Farmer circumstances in the...
 Chatacteristics of the technological...
 Analysis of farmers' actual adoption...
 List of available CIMMYT economics...

Group Title: CIMMYT working paper ; 82/4
Title: The rate and sequence of adoption of improved cereal technologies
Full Citation
Permanent Link: http://ufdc.ufl.edu/UF00080079/00001
 Material Information
Title: The rate and sequence of adoption of improved cereal technologies the case of rainfed barley in the Mexican Altiplano
Series Title: Working paper
Physical Description: 43 p. : ; 28 cm.
Language: English
Creator: Byerlee, Derek
Hesse de Polanco, Edith
Publisher: International Maize and Wheat Improvement Center
Place of Publication: México D.F. México
Publication Date: 1982
Subject: Barley -- Mexico   ( lcsh )
Agricultural innovations -- Mexico   ( lcsh )
Genre: bibliography   ( marcgt )
non-fiction   ( marcgt )
Spatial Coverage: Mexico
Bibliography: Includes bibliographical references (p. 42-43).
Statement of Responsibility: by Derek Byerlee, Edith Hesse de Polanco.
Funding: CIMMYT economics program working paper ;
 Record Information
Bibliographic ID: UF00080079
Volume ID: VID00001
Source Institution: University of Florida
Rights Management: All rights reserved by the source institution and holding location.
Resource Identifier: oclc - 31174786

Table of Contents
    Front Cover
        Front Cover
    Title Page
        Title Page
    Table of Contents
        Table of Contents
        Page 1
        Page 2
    Sources of data
        Page 3
        Page 4
        Page 5
    Farmer circumstances in the Altiplano
        Page 6
        Page 7
        Page 8
    Chatacteristics of the technological components and the predicted adoption pattern
        Page 9
        Page 10
        Page 11
        Page 12
        Page 13
        Page 14
        Page 15
        Page 16
        Page 17
        Page 18
        Page 19
        Page 20
        Page 21
    Analysis of farmers' actual adoption patterns
        Page 22
        Page 23
        Page 24
        Page 25
        Page 26
        Page 27
        Page 28
        Page 29
        Page 30
        Page 31
        Page 32
        Page 33
        Page 34
        Page 35
        Page 36
        Page 37
        Page 38
        Page 39
        Page 40
        Page 41
        Page 42
        Page 43
    List of available CIMMYT economics working papers
        Page 44
Full Text






Derek Byerlee
Fdith Hesse de Polanco

Working Paper 82/4

Views expressed in this paper are not necessarily those of CIMMYT.


From 1971 to 1976 the CIMTYT Economics Program sponsored a series
of adoption studies on wheat and maize technologies, particularly var-
iety and fertilizer, in six countries. The results of these studies
emphasized the importance of the agroclimatic and socioeconomic circum-
stances of farmers in explaining adoption patterns. Where nonadoption
occurred, it was usually found that the technology was not consistent
with farmer circumstances; that is, adoption was more a function of the
characteristics of the technology than characteristics of the farmer,
such as age, sex, education and extension contacts, which had been em-
phasized in previous adoption studies.
The current study strengthens these conclusions by bringing togeth-
er new and different sources of data from a region in which CIMMYT has
been working over the last five years. Data from on-farm experiments
over several years enable more precise measures of technological charac-
teristics, such as profitability and risk. Time series data from a ran-
dom sample of farmers provide unique information on farmers' adoption
patterns over a five-year period. Finally, instead of analyzing adop-
tion of one component alone, such as variety, the present study jointly
considers a series of both biochemical and mechanical technological com-
ponents in which the effect of interactions among technological compo-
nents is also analyzed.

Donald L. Winkelmann, Director
Economics Program


We are grateful to Edgardo Moscardi for the use of data from a farm
survey he conducted in 1975 in which detailed records of names and ad-
dresses of farmers and locations of their field enabled us to easily
resurvev the same farmers in 1980. We also appreciate the excellent co-
operation from the CTI1YT Wheat Training Program, especially Paul Marko,
Hikmat Nasr and Ron Knapp, who have conducted the on-farm experimental
program from which data are extracted for the analysis in this paper.



Introduction 1

Sources of Data 3

Farmer Circumstances in the Altiplano 6
Agroclimatic Circumstances 6
Socioeconomic Circumstances 7
Sources of Improved Technologies 8

Characteristics of the Technological Components and the
Predited Adoption Pattern 9
A Model for Analyzing Adoption Decisions as a
Function of Technological Characteristics 9
Overview of the Technological Components Analyzed 10
Characteristics of the Mechanical Technological Components 12
Characteristics of the Biochemical Technological Components 14
Interactions Between Technological Components 19
Predicted Adoption Sequence 21

Analysis of Farmers' Actual Adoption Patterns 22
Logit Analysis of Major Factors Affecting Adoption 23
Logistic Curves of Adoption Patterns 24
Adoption Path for Mechanical Technological Components 29
Adoption Path for Biochemical Technological Components 32
Technological Packages versus Step-wise Adoption 33




In efforts to understand the process of agricultural development,
economists and other social scientists have invested substantial re-
sources in literally hundreds of studies of the adoption of new agricul-
tural technologies. Recent reviews of these studies (Rogers, 1976;
Byrnes, 1982; Feder, 1981) indicate that despite this large amount of
research, there remain three major deficiencies in our empirical know-
ledge of the adoption of agricultural technologies. First, most adop-
tion studies have had a "pro-innovation" bias that assumes that the in-
novation is "right" and that patterns of adoption therefore relate to
the socioeconomic characteristics of the farmer. However, the extensive
series of adoption studies completed by the CI.MYT Economics Program
highlighted the fact that major differences in adoption of technologies
usually arose from variation, sometimes subtle, in the agroclimatic en-
vironment (Perrin and Winkelmann, 1976). Farmers rejecting the technol-
ogy were acting quite rationally because the technology was not suitable
for their particular circumstances. The only farmer characteristic that
consistently appeared as important in the CIMMYT studies was farm size
and, even here, there was evidence that after an initial time lag, small
farmers usually adopted the same technologies as larger farmers.
A second deficiency is that adoption studies have been of a "snap--
shot nature", based on data on adoption and nonadoption at one point in
time. Of the studies reviewed by Rogers (1976), only six percent used
time series information; yet adoption is by nature a dynamic process
that occurs over time. The failure to recognize this, led early studies
of the adoption of new wheat varieties of the so-called Green Revolution
to conclude that large farmers benefited more from the new technology.
Later studies have shown that small farmers generally followed large
farmers in accepting the technology (Byerlee and Harrington, 1982).

Finally, adoption studies have usually focused on only one innova-
tion among a set of practices used for growing a crop (Feder, 1981). At
the same time, agricultural researchers and extension agents have typi-
cally promoted a "package" of practices consisting of a number of tech-
nological components. Proponents of the "package" approach argue that a
package captures the positive interactions between several components.
On the other hand, because of capital scarcity and risk considerations,
farmers are rarely in a position to adopt complete packages. Moreover,
there is evidence that packages can often be disaggregated into pieces
or "clusters" (Mann, 1977) of one or two components which allow critical
interactions to be exploited and enable adoption to follow a sequential
pattern with elements initially adopted providing the highest rate of
return on increments in capital expenditures (Ryan and Subrahmanyan,
1975). This question of single technological components versus packages
is important since it has implications for the way experiments are de-
signed, as well as for the recommendations promoted to farmers.
This paper aims to interpret the rate and sequence of adoption of
an array of technological components followed by farmers in barley pro-
duction in the Altiplano of Mexico. The emphasis is on interpreting
rates and sequence of adoption in terms of the characteristics of the
technology, such as profitability, risk and divisibility, rather than
such characteristics of the farmers as age, education and extension con-
tacts, which have dominated previous adoption studies. An unusually rich
data base enables us to treat some of the major deficiencies in previous
adoption studies. A total of eight technological components including
both mechanical and biochemical technologies are analyzed. Adoption of
these technological components is traced over a five-year period, since
surveys have been conducted with the same random sample of farmers in
both 1975 and 1980. During this same five-year period, an extensive
series of on-farm experiments has been conducted in the area, which pro-
vides good information on the performance of many of the technological
components and their interactions under farmers' conditions. Finally,
the study area is characterized by considerable variability with respect
to agroclimatic factors and farm size, both found to be important in
interpreting different rates of adoption of agricultural technologies in
the earlier CIMMYT studies by Perrin and Winkelmann (1976).

The sequence of adoption of technological components in small
grains (wheat and barley) in drier areas with relative labor scarcity,
such as the Mexican Altiplano, is also of particular interest because of
the somewhat conflicting evidence currently available. Bolton (1979), an
agronomist, hypothesizes an adoption sequence that emphasizes biochem-
ical technologies, especially weed control followed by fertilizer, to
more efficiently utilize available moisture. It is assumed that tillage
methods to conserve moisture depend on tractor mechanization and will be
adopted more slowly. Yet evidence from the drier areas of Turkey (Mann,
1982), Jordan (El Hurani, 1980) and Algeria (Masson, 1981) all suggest
that tractor mechanization of initial tillage operations using (in many
cases) rented tractors, precedes the use of biochemical technologies.
However, most agree that changes in agronomic practices will be initial-
ly more important than varietal changes in drier areas (Byerlee and
Winkelmann, 1981).
The analysis in this paper is developed in the following order.
After a brief description of the study area and data collection methods,
we construct a list of technological characteristics that we hypothesize
to be important in farmers' adoption decisions. Evidence from on-farm
experiments in the study area is used to rank technological components
according to these characteristics and hence predict the rate and se-
quence of adoption. We then use longitudinal farm survey data to examine
actual adoption patterns in light of these predictions and interpret the
rate and sequence of adoption among the array of technological compo-
nents. This also enables us to draw conclusions about the effects of
interactions between technological components and the question of tech-
nological pieces versus packages.

Sources of Data

Tn 1975, CIMMYT's Wheat Training Program began an on-farm research
program in the Mexican Altiplano for the purpose of training agronomists
in rainfed wheat and barley production. The study area, shown in Figure
1, consists of parts of the States of Hidalgo, Mexico and Tlaxcala, that
are within about one hours' drive from CIMMYT Headquarters and where
barley is an important crop.

Figure 1. Mop of the Study Area


SEpazoyucon .o. .M

Tolcayuca / Singu ...

Zempoal o

Temascaltion practices as a basis for designing on-

Twere chosen by randomly identifying points on a map of scale
toMexico.e. .

Texcoco CIMMYT

Majo foodsOP PUEBLA Espoito
Arajor roods

Dry zone

In 1975 a survey was conducted with the objective of gathering in-
formation on barley production practices as a basis for designing on-
farm experiments on barley and wheat in the study area. A total of 54
randomly selected farmers were interviewed in this survey.1/ These same
54 farmers were revisited in 1980 and data collected on the same pro-

Since no complete lists of farmers were available, these farmers
were chosen by randomly identifying points on a map of scale
1:50000. These points were located on the ground and the farmer
working that field identified and interviewed. This sampling proce-
dure led to some bias toward large farmers who have larger fields
and/or a larger number of fields and hence statistics presented at
the regional level are biased toward large farmer practices.

duction practices and where possible for the same field.- These surveys
are unique in enabling a longitudinal tracking of farmers' practices
over a five-year period of rapid change in the area. Data quality in
each survey is high. Experienced research assistants from CIMMYT con-
ducted the 1975 farmer interviews under close researcher supervision. In
1980, we conducted or were present in nearly all the interviews. How-
ever, the sample size is small in relation to the variability in the
In 1979, another survey of 87 farmers was carried out in only the
southeastern and wetter parts of the study area in the valley of Calpu-
lalpan and Apan. The main objective of this survey was to gather more
detailed information and understanding of farmers' practices and prob-
lems in order to help plan experiments of the Wheat Training Program in
this area. Results of the survey are described in Byerlee, Harrington
and Marko (1981). In this survey, farmers were asked the year in which
they first used selected new practices. Because of the larger sample
size and greater detail, information from this survey is used to sup-
plement the results of the longitudinal results.
An on-farm experimental program has been a major component of
CIMMYT's production agronomy training program since its beginning. On-
farm experiments in the study area generally consisted of research and
verification experiments. These experiments have focused on the major
agronomic problems of barley, i.e. variety, fertility (mostly nitrogen
and phosphorous), weeds and stand establishment. For the purpose of this
study, the results of 106 experiments over a five-year period have been
analyzed to obtain response data on improved practices under farmer con-
ditions. The experiments, however, were concentrated in the wetter zone,
so disaggregation into rainfall zones sometimes leaves relatively few
observations in the drier zone.

- In two cases, the selected field was worked by a different farmer,
and in a few cases maize was planted in the selected field, so
questions were asked about the barley production practices in one
of the farmers' other fields. In eight cases, the farmer did not
plant barley in 1980, so that final sample size in 1980 was reduced
to 46 farmers.

Farmer Circumstances in the Altiplano

Agroclimatic Circumstances

The study area is characterized by considerably heterogeneity in

agroclimatic circumstances of farmers. These same circumstances also

vary considerably from year to year, creating substantial risk to farm-

ers. Annual average rainfall varies from less than 450 nm in the western

part of the study area to more than 700 nm in the southeastern part.

Based on rainfall data and experience obtained in five years of experi-

mentation, the study area was divided into wet and dry zones. Rainfall

distributions for representative sites in each zone are shown in Figure

Figure 2. Histogram of Monthly Rainfall Distribution for Sites in Each Rainfall Zone

Wet Zone: Colpulalpan
(Average AnnualRainfall 1948-1978: 635 mm)



Dry Zone: Tezontepec
(Average Annual Rainfall



F -r 14 10-
814 14 l


1948-1978: 536 mm )

-- 1 80


- I I

J A J J A S 6 Nk D

S] Average monthly precipitation over a//years
[ ] Average monthly precipitation in 20% of driest cases

Source: Unpublished data from Servicio Meteoroldgico Nocional,Mdxico



j A S 0 N D


1B 7

- r I


I 41

2. In the dry zone, rainfall is lxbth lower and less reliable. On the
basis of on-farm experimental results, we estimate that in this zone
farmers suffer total or almost total crop losses one year in five. In
the wet zone, this probability falls to one year in twenty.
With an average altitude of over 2500 meters above sea level, the
length of the growing season in the study area is also constrained by
the incidence of frosts in the latter part of the season (September and
October). This means that late planted barley (late June) that matures
in 120-125 days runs a significant risk of frost damage.-
The region can be further disaggregated into flat and sloping land.
On sloping land there are severe erosion problems. The planting of the
perennial cactus "maguev" on the contour is one measure used to reduce
erosion damage. In this case, barley is interplanted among maguey rows,
but narrow inter-row distance often prevents or complicates mechaniza-
tion of operations.

Socioeconomic Circumstances
Major crops grown in the study area are barley, maize and maguey.
Maize is the subsistence crop and relatively little is marketed. Barley
is the cash crop. Two distinct markets exist for barley--for forage and
for malting. Traditionally, most barley was produced for animal forage,
either for the farrier's own animals or for sale. However, as the de-
mand for beer in Mexico has increased rapidly throughout the 1970s, much
more barlev is now produced for malting purposes, especially given the
location of the area near large breweries in Mexico City.
Farm size and land tenure arrangements vary considerably over the
study area. Small farmers with less than 20 hectares predominate; these
tend to hold land under the ejido system of the land reform program al-
though there are also some small private farmers. Larger farmers with

S Normally, rainfall is sufficient to allow earlier planting, but
farmers who delay planting after opening rains to control weeds or
for lack of machinery, run the risk of early frost.
2- Data from the 1970 Agricultural Census indicate that approximately
60 percent of barley was produced for forage purposes in the wet
zone, and nearly all barley produced in the dry zone was for

over 20 hectares of land control a substantial share of the total crop-
ped area. These farmers own land privately and the largest farmers (over
100 hectares) often rent additional land.
Several features of the economic environment are important to un-
derstanding technological change in the study area. Barley prices, in-
fluenced by the increasing demand for malting quality barley and the
higher proportion of barley sold for malting purposes, have risen rela-
tive to competing activities. From 1975 to 1980, prices received by
farmers for barley increased by over three times, compared to a doubling
of maize prices and a 162 percent increase in the consumer price index.
At the same time, real wage rates have increased by about 20 percent in
response to alternative opportunities in the nonagricultural sectors in
the area (including an industrial complex at Sahagun and a state capital
at Pachuca), as well as in the nearby Mexico City labor market.l

Sources of Improved Technologies
Several institutions have a role in promoting improved technology
in the area. A private organization of major breweries, Impulsora Agri-
cola, has promoted barley production for malting purposes, especially
among large farmers, in several ways: (1) through distribution of im-
proved varieties of higher malting quality, (2) by providing technical
advice, and (3) by acting as a buying agent. The official credit bank
also requires as part of its loan the use of a package of inputs that
usually includes an improved variety, herbicide and fertilizer. There is
an extension service, although its primary activity is to provide tech-
nical advice through the official bank. They do not have a demonstration
program, nor is there a research program operating in the area to pro-
vide recommendations to farmers. However, there is no doubt that the
CIMMYT on-farm research/training program, through its on-farm experi-
ments and demonstrations, has also had some impact on the spread of new

- Real wage rates were calculated by deflating money wages by the
official consumer price index.
2- INIA, the national agricultural research institute, has successful-
ly developed improved barley varieties, but has done relatively
little research on management practices for the area, especially
under farmers' conditions.

technologies, even though its major objective has been training. Final-
Iv, farmers themselves have been a major source of innovation. Many
large farmers have contacts with farmers in more advanced irrigated
areas in other parts of the country, or even contacts abroad, and bring
back new ideas and inputs for experimentation.

Characteristics of the Technological Components and the
Predicted Adoption Pattern

A Model for Analyzing Adoption Decisions as a Function of Technogical
In this study, we emphasize the characteristics of the technology
as they affect the pattern of adoption. A technology is the aggregate of
all practices or technological components used to grow a crop. A prac-
tice or technological component is defined by the time, method and in-
tensity of a particular operation in crop production. For example, a
practice for weed control with herbicide is defined by the type, method,
rate and time of application of the herbicide. The adoption pattern of a
particular technological component can be defined by the time of initia-
tion of adoption and the rate of adoption once initiated. Given a series
of independent technological components with no interaction between the
components, we hypothesize the adoption pattern to be defined by five
characteristics of the technological component: a) profitability, b)
riskiness, c) divisibility or initial capital requirements, d) complex-
ity, and e) availability.-
Profitability, defined here as return to investment in a given
technological component, is expected to be an overriding factor in farm-
ers' adoption decisions. Farmers with capital constraints will adopt
that practice giving highest returns to available capital. However,
adoption of a profitable technology is expected to be slower if it in-
creases risks. Divisibility of the technology measured in terms of ini-
tial cash costs may also affect rates of adoption patterns--large fanm-
ers are expected to adopt less divisible inputs before small farmers.

- Byrnes (1982) hypothesizes similar but not identical characteris-
tics consisting of observability, comparability, profitability,
reliability and trialability.

Technological components requiring more management complexity may re-
quire a longer time to diffuse as farmers build up sufficient experience
to capture potential returns from using the technology. Finally, all
these factors are modified by the availability of inputs, equipment and
information for each technological component, which in turn is a func-
tion of such institutional factors as the relative role of the private
and public sector in providing inputs and information to farmers.
Profitability and riskiness of a component are themselves a func-
tion of elements of the agroclimatic and socioeconomic environment, such
as rainfall and prices. Moreover, heterogeneity in the farm population
is likely to lead to a slower rate of adoption because of differences in
risk aversion, management capacity, information and capital availability
among farmers in the population. Farm size, which has been identified as
an important variable in previous adoption studies (e.g. Perrin and
Winkelmann, 1976; Feder, 1981), is a proxy for many of these factors.
Finally, interactions between technological components will affect
adoption patterns. Where positive interactions exist, the adoption of
one technological component is expected to accelerate the adoption of
additional components. In the extreme case, where inputs are perfect
complements, all technological components would be adopted as a package
since no one component would function without the presence of the

Overview of the Technological Components Analyzed
A total of eight different technological components are examined in
this study. Table 1 compares the "improved" method with the "tradition-
al" method. These improved practices have been divided into mechanical
components and biochemical components. Following Hayami and Ruttan
(1971), the mechanical components are labor saving while the biochemical
components are yield increasing or land saving. Hence, we expect a some-
what different adoption pattern depending on relative factor prices.
Also, it is generally assumed that mechanical technologies favor large
farmer adoption, while biochemical technologies are essentially scale
neutral and, given equal access to input and product markets, can be
equally well adopted by either small or large farmers.

Table 1. Comparison of Different Elements of the Traditional
and Improved Technologies



Mechanical Components

1. Land Preparation

a. Power source and
implement for
initial tillage

b. Intensity of tillage
prior to planting

c. Timing of initial

2. Planting

3. Harvesting

Biochemical Components

1. Variety

2. Weed Control

3. Fertilizer

Animal with wooden or
steel plow

One tillage operation
and sometimes none

After rains begin in

Broadcast and covered
by tillage implement

Cutting by hand4 and
threshing with animal
or stationary thresher

"Comun" a variety in-
troduced by the Spanish
in the colonial period

None or same hand

None or use of some
organic manure

Tractor with disc plow
or subsoiler

Ploughing combined with
one or more harrowings

After the previous har-
vest in October to

Use of seed drill

Use of combine

Apizaco, Cerro Prieto
and other varieties
released by the Mexican
research institute
(INIA) since 1965

Use of back-pack sprayer
to apply 2,4-D herbi-
cide to control broad-
leaf weeds

Application of nitrogen
and sometimes phospho-
rous fertilizer.

/ A few farmers also employed an intermediate harvesting technique, using a
horse or tractor drawn "stripper" to cut and then to transport the barley to
a mechanical thresher. This practice is not analyzed in this study.

- -


Characteristics of the Mechanical Technological Components
The mechanical components examined in this study essentially repre-
sented the replacement of animal or human power by motor power. There is
considerable evidence that the cost of motor power is substantially
cheaper than their animal- or human-powered counterparts. By 1980, the
cost per hectare of renting animals for ploughing was double the cost of
renting a tractor, and this did not include the cost of labor or forage
in using rented animals. Likewise, in 1980 the cost of hand harvesting
was more than double the cost of mechanical harvesting by combine (Table
2). Even assuming hand harvesting is performed by lower cost family la-
bor (which is not usually the case), hand harvesting still requires the
use of a stationary thresher, which is only marginally cheaper than a
combine harvester.
The use of the drill to replace hand-broadcasting of seed is the
only mechanical technology in which there is no real cost advantage,
largely because little labor is employed in hand-broadcasting; about 0.5
person-days/ha is required compared to at least 5 person-days/ha for
hand harvesting.
There is also considerable evidence that the cost of mechanization
has declined over time. The real cost of tractor ploughing and combine
harvesting in terms of grain equivalents has decreased by about 20
percent over the period 1975 to 1980 (Table 2). The increased competi-
tion to provide rental services arising from an increased number of ma-
chines, a steadily increasing subsidy on fuel, and a favorable sales tax
and import duties for agricultural machinery, have been factors in this
declining real cost. Over the same period, the cost of labor in grain
equivalents has remained steady, indicating a fall in the relative
costs of mechanical practices.

Because we are using price and cost data from two points in time in
a period of rapid inflation, we have converted money costs to grain
equivalents using field prices of barley of $1.3/kg in 1975 and
$4.1 in 1980.
2- As mentioned earlier, the real wage rate calculated by deflating
money wages by the consumer price index has risen by 20 percent.

Table 2. Costs of the Mechanical Technological Components
in 1975 and 1980

Year Percent Change
1975 1980 1975 to 1980

(kg of grain equivalent per ha)a

Animal rental for ploughing n.a. 220 n.a.

Tractor rental for ploughing 153 122 -21

Tractor rental for harrowing 77 61 -21

Rental of drill n.a. 73 n.a.

Rental of combine 230 195 -16

Hand harvesting (with labor cost) 531 497 -6
(without labor
cost) 223 192 -14

(kg of grain equivalent per day)

Unskilled wage rate per day 31 30 -3

a/ Based on field price of barley of $1.3/kg in 1975 and $4.1/kg in 1980.

n.a. not available.

These cost differences might be modified if there are yield effects
of the mechanical technologies, especially since a switch to tractor
power also involves a change in tillage implements. Because the on-farm
experimental program emphasized biochemical technologies, we do not have
complete evidence on yield effects. Eight experiments were carried out
over the period to compare broadcasting and drilling. Broadcasting out-
yielded drilling by 8 percent, but the difference was not significant.
However, drilling does allow large farmers with limited labor to plant
in a more timely manner.- Two experiments were also conducted on addi-
tional tillage operations in 1979 and 1980 and showed an average yield
increase of 315 kg/ha to one additional harrowing. This is similar to an
estimated yield response of 280 kg/ha derived from an analysis of farm-
ers' yields in 1979 (Byerlee, Harrington, Marko, 1981). These yield
increases compare very favorably to an estimated cost of 60 kg/ha in

SIn the 1979 survey, farmers with over 20 ha planted an average of
one week earlier if they used a drill.

grain equivalents for the additional harrowing.
The other characteristics of the mechanical technologies--riski-
ness, divisibility, complexity and availability--depend largely on the
type of farmer. For a large farmer who purchases his own tractor, we
expect divisibility to be a problem, but risk may he reduced since more
timely operations are possible.- However, complexity is increased be-
cause of the need to manage and maintain the equipment. For small farm-
ers who adopt by renting machinery, divisibility is overcome and there
is no problem of increasing complexity, since the farmer rents the
operator as well as the machine. However, availability and riskiness may
be a problem, since in a limited rental market, farmers may have to
queue for machinery services. There is evidence that tractor renters
perform less timely operations than owners because of the difficulty in
obtaining a tractor when moisture conditions are appropriate for tillage
or planting (Byerlee, Harrington, Marko, 1981). However, it is expected
that as the rental market develops and a larger number of tractors be-
comes available, these problems should be reduced.2

Characteristics of the Biochemical Technological Components
Characteristics of each biochemical component are shown in Table 3
and Figure 3. Profitability and riskiness of the technological compo-
nents have been calculated from the results of the on-farm experiments
conducted from 1976 to 1980. Calculations in Table 3 do not consider
interactions, which are analyzed separately in the following section. We
have disaggregated the analysis into wet and dry zones, because the re-
sults are quite sensitive to rainfall.-

/- Risk may be reduced by increased moisture conservation in dry years
through earlier tillage and better weed control prior to planting.
Drilling may also enable better placement of seed in relation to
moisture in a dry seed bed.

SUntil recently, machinery services in the area have been entirely
the province of the private sector. Now, the official credit bank
is also giving loans to groups of small farmers for machinery pur-

S For example, average yields in the variety experiments in the dry
zone were 1.60 ton/ha with a coefficient of variation of 55 percent
compared to average yields of 2.45 ton/ha and a coefficient of
variation of 27 percent in the wet zone.

Rates of return to investment, as a measure of profitability, were
calculated following the methodology of Perrin et al. (1976). Full de-
tails and assumptions are given in Appendix A. Of the three biochemical
components, improved variety gives the highest rate of return on invest-
ment in both rainfall zones. This arises despite the fact that average
yield increases from using improved varieties were only 11 percent in
the wet zone and 3 percent in the dry zone. However, the cost of chang-
ing variety is low, since seed may be kept over several years. Also the
major factor leading to high profits from using newer varieties has been
the development of a market for barley of malting quality. This has led
to an average price premium for improved varieties of 10 percent over
prices received for the local variety, which has poor malting quality.
Returns to improved varieties are particularly high in the wet zone.
Herbicide, and then fertilizer follow variety in terms of profita-
bility in the wet zone, where both give significant increases in yields.
Herbicide gives particularly high returns at 1980 prices in the wet zone
where weed problems are more severe. At 1975 prices, herbicide use was
only marginally profitable in the dry zone, but because of a decline in
real prices should be attractive to farmers in 1980. Similarly, returns
to fertilizer use have increased dramatically from 1975 to 1980, reflec-
ting a 44 percent decline in the real price of nitrogen fertilizer mea-
sured in grain equivalents. The higher return to fertilizer use in the
dry zone reflects a lower optimal fertilizer dose,- a smaller number of
observations, and the dominance of two unusually high yielding sites.
The distribution of yields over sites and years in the experiments
was used to calculate two measures of risk in each rainfall zone for
each biochemical component. In both cases, it is assumed that risk
averse farmers are concerned about consequences at the lower end of the
distribution of economic benefits, i.e. the worst results. First, the
absolute risk from using the new component was calculated by the gain or
loss in grain equivalents for the lowest 20 percent of the distribution

/- The optimal dose in the dry zone was estimated to be 45 kg/ha of
nitrogen, compared to 80 kg/ha of nitrogen in the wet zone.

Table 3. Characteristics of the Biochemical Technological
Components in 1975 and 1980

Improved Variety / Herbicide

Average yield increase (kg/ha) -

Marginal rate of return on in-
vestment (percent/year)

Risk Measure I (kg/ha grain
equivalent gained or lost in
20% worst cases at 1980 prices)

Risk Measure II (estimated prob-
ability that net benefits of im-
proved technological ccnponents
are less than those of tradi-
tional technological components
at 1980 prices)

Initial cash costs (kg/ha grain




Wet Dry
Zone Zone

43 282* 118

1419 411
2172 667

122 -19

6 36

87 -17

13 22

Fertilizer -

Wet Dry
Zone Zone

598* 451*


-15 -113

13 33

* Significantly different from check treatment at 5 percent level.

aRefers to purchase of certified seed. Seed from other sources (e.g. neigh-
bors) usually costs less. In addition, it can be used over a five-year

b80 kg/ha of nitrogen in the wet zone and 45 kg/ha of nitrogen in the dry

/ Calculated taking into account lost sites.

Source: Based on on-farm experimental data, 1976 to 1980 (see Appendix B).

Figure 3. Comparison of Yield Increase, Marginal Rate of Return on Capital and Risk of the Three Biochemical
Technological Components




V [~~ Use of Improved Varieties (Apizaco, Cerro Prieto, Centine/o, Pueblo)
H W Use of Herbicide (2 It/ho Esteron 47)
F E I Use of Fertilizer (80 kg/ha and 45 kg/h of Nitrogen in Wet and Dry Zone Respectively)

/ Calculated at 1980 prices

Source: Based on results from on-farmexperiments, 1976-80

as in Perrin, et al. (1976). Second, we calculated the incidence of risk

by estimating the percentage of years in which farmers would experience
an economic loss (i.e. negative returns on capital) for a given change

in technology when compared to the traditional practice.-

In the case of variety, there is virtually no risk from using im-

proved varieties in the wet zone and only a very small risk in the dry

zone--whichever risk measure is used. In the dry zone, the local variety

gives higher returns in over one-third of the years but, because the

In each case the distribution of yields over many experiments and
years is assumed to represent true year to year variation faced by
farmers. In practice, the distribution also includes site to site
variation which we have reduced but not eliminated, by stratifying
by rainfall zone.

cost of'chanqing varieties is not high, the absolute risk is not high.-
Herbicide was not considered risky in the wetter zone. Herbicide
gave positive returns in the wet zone even for the 20 percent worst re-
sults. However, in the dry zone, because the incidence of crop loss is
about one in five, use of any input is risky. Even so, absolute losses
from herbicide use in the dry zone are not high because of its low cost.
Moreover, since herbicide is applied one month after planting, the farm-
er can reduce risks by not applying if the crop shows poor early devel-
Finally, fertilizer is by far the most risky of the inputs consid-
ered, although losses are small in the wet zone. In the dry zone, fer-
tilizer use (at a lower dose of 45 kg/ha of nitrogen) is risky even for
the worst 33 percent of the results and expected losses in the driest
years are over 100 kg/ha in grain equivalents.
In terms of initial capital costs, the lowest cost change is for
herbicide use, provided a back-pack sprayer is rented. A capital outlay
of only about 50 kg/ha in grain equivalent was necessary for adoption of
herbicide in 1980. The initial cost of using an improved variety depends
on the source of seed. If certified seed is used, initial costs are
quite high. However, most farmers who do not work with the bank pur-
chased seed from friends and neighbors at substantially lower prices.
Fertilizer use at recommended doses is the most costly change, but like
the other biochemical inputs, it is divisible and hence initial adopters
with scarce capital can use lower doses.

I- Also for variety, stability parameters were calculated for the six
most commonly used varieties in the study area following the method
of Eberhard and Russell (1966). Yield of individual varieties was
regressed on the mean yield of all varieties at that location. A
slope of the regression line greater than one indicates relatively
better response to good conditions, while thy intercept indicates
the response under poor conditions. A high R indicates wide adap-
tation. The local variety ComGn and the improved varieties, Apizaco
and Cerro Prieto, had a slope of less than one, while the new early
varieties, Centinela and Puebla, show greater response to better
environments. The local variety also shows the widest adaptability,
as indicated by the high R while Centinela shows quite variable
performance. This often arises because a dry spell during the
growing cycle does not allow this early variety to recover. By
these measures, Com6n, Apizaco and Cerro Prieto are less risky var-
ieties and in fact, were the most widely grown varieties in 1980.

Variety is also the least complex of the changes, providing there
are no strong variety by management interactions (see next section).
Seed of the new variety is simply substituted for that of the old var-
iety at the same seed rate. Fertilizer and herbicide both require cal-
culations of dosages per unit of area and judgements on the appropriate
time of application in relation to crop development and climatic condi-
tions. Fertilizer represents an additional complication in the study
area because of the number of different products with varying nutrient
composition, which requires that farmers have some knowledge of nutrient
needs and the ability to calculate dosages. On the other hand, only one
herbicide product is commonly used on barley.
Finally, the availability of the different inputs varies. Both seed
for improved varieties and herbicide are available in private stores or
veterinarians" Moreover, a farmer working with the official credit bank
is usually obligated to use improved seed provided through the bank.
Fertilizer, on the other hand, is only available through the official
credit bank or government owned stores. Distribution points were few
and stocks of fertilizers erratic, so farmers using fertilizer had to
travel a considerable distance to obtain supplies.

Interactions Between Technological Components
Some limited evidence is available on the interaction between var-
iety, herbicide and fertilizer. Five experiments have been conducted on
variety by management with local and improved varieties being tested
with and without the application of fertilizer and herbicide. Results
are shown in Figure 4. At low management levels, there was no difference
between local and improved varieties. At high management levels, the
improved variety gives significantly higher yields, since the local var-
iety tends to lodge with the application of nitrogen fertilizer. A fur-
ther variety by weed control interaction arises in the market for mal-
ting quality barleys that are discounted for weed seed impurities. This
further raises the return from herbicide weed control in improved var-

Figure 4. Variety by Management Interactions in the Wet Zone

Improved Varieties

2500- / Local Variety
5 / 0/



Without Herbicide
Without Fertilizer

Application of 2/t/ha Esteron 47Herbicide
Application of 80kg/ho of Nitrogen

Source: Calculated from data from 5 on-form experiments during 1976-80

Twelve experiments have been conducted on fertilizer by herbicide
use, mostly in the wet zone. As expected, there was positive interaction
between herbicide and fertilizer. Marginal rates of return analysis
shown in Figure 5 strongly indicates the sequence of adoption to be
herbicided followed by fertilizer. The addition of herbicide alone costs
little and provides high returns. The addition of fertilizer alone, how-
ever, gives much lower returns and was only marginally profitable at
1975 prices. Figure 5 also indicates the extent to which real costs of
adoption of biochemical technologies have fallen since 1975.

Figure 5. Net Benefit Curves Showing Interaction of Herbicide and Fertilizer
in the Wet Zone at 1975 and 1980 Prices2/

/ 4- 1975 Prices

T traditional technology
H application of 2 It/ha Esteron 47
F F application of 80 kg/ha of nitrogen
H+F application of herbicide and nitrogen

Total Costs That Vary
(kg/ha grain equivalent)

Net benefits andmarginalrates ofreturn calculated at 1975prices
---- Net benefits and marginalrates of return calculated at 1980 prices

./Numbers in brackets ore marginal rates of return on investment
Source: Calculated from data from9on-form experiments during 1976-80

Predicted Adoption Sequence

In sum, there is substantial evidence that factor price relation-

ships favor rapid mechanization of land preparation and harvesting but

not drilling. Yield effects of additional tillage operations and prob-

ably of earlier tillage, are also associated with tractor use for land

preparation. However, adoption patterns are likely to be strongly in-

fluenced by farm size, as larger farm size favors machinery ownership.

Small farmers who adopt by renting machinery should lag in their adop-

tion of machinery, especially if rental services are provided by larger

farmers. Finally, we expect adoption of mechanical components to be in-

fluenced by topography, since large machinery can be used more efficien-

tly on flat open land. In the study area, the interplanting of barley

and maguey on sloping land complicates the use of machinery.

Among the biochemical components, the evidence on rates of returns,
risk, complexity, and availability all points toward an adoption se-
quence of variety followed by herbicide and then fertilizer, at least in
the wet zone. Note that yield increases run in the reverse order from
about 600 kg/ha for fertilizer to only 250 kg/ha for variety in the wet
zone (Figure 3). Data on interactions between these components also sug-
gest adoption in the same order to enable exploitation of high marginal
returns on initial capital expenditures. Although there are positive
interactions between herbicide and fertilizer, these inputs can be adop-
ted separately with strong indications in the wet zone that it will be
more effective to adopt herbicide before fertilizer.
We are not able to analyze interactions between the biochemical and
mechanical technological components. However, three observations are
relevant. First, the initial cost of mechanical components when adopted
by renting are not high in relation to the biochemical components, espe-
cially at 1975 prices. However, the initial cost of the biochemical com-
ponents in terms of grain equivalents has fallen by 30 percent for herb-
icide and 44 percent for fertilizer, compared to 20 percent for me-
chanical components. Hence, we expect more rapid adoption of biochemical
components in later years. Second, we expect complementarity between
moisture conservation practices, such as early tillage and additional
secondary tillage, and the use of such biochemical components as im-
proved varieties and fertilizer. Finally, the use of yield-increasing
biochemical components is likely to place a premium on mechanical har-
vesting, in which costs are relatively insensitive to yields.

Analysis of Farmers' Actual Adoption Patterns

Two measures of adoption were used in this study. First, farmers
were asked about the use of a given practice in the year of the survey.
This provides a longitudinal measure of adoption of specific technolo-
gical components in 1975 and 1980. This measure may underestimate adop-
tion if a particular practice was not used in the survey year because of
climatic or other reasons. Second, we asked farmers if they had ever
used a given practice and if so in what year they first used this prac-
tice. This measure could overstate actual adoption since some farmers

may have adopted and then rejected a practice. In fact, we rarely en-
countered this in the survey.
Both measures of adoption were used to analyze adoption patterns in
a two-step procedure. First, given the substantial variability in farm-
ers circumstances encountered in the area, we wanted to divide farmers
into more homogeneous subgroups for the analysis of adoption patterns.
logit analysis of actual use of a practice was employed for this pur-
pose. Second, the time of initiation of adoption and the rate of adop-
tion of each technological component for each subgroup was estimated by
fitting a logistic curve to data based on farmers recall on the year of
adoption. Parameters of these logistic curves were then used to compare
adoption patterns across technological components for each farmer sub-

Logit Analysis of Major Factors Affecting Adoption
To delineate subgroups of farmers, we used a logit analysis to re-
late adoption of each technological component to major variables ex-
plaining different agroclimatic and socioeconomic circumstances of farm-
ers." These variables were rainfall, topography, farm size and some-
times use of bank credit. We have already seen from the analysis of the
on-farm experiments that rainfall has an important effect on returns and
risk from using the biochemical technological components. Topography has
been identified as important in other adoption studies (e.g. Perrin and
Winkelmann, 1976) probably as a proxy for information and market access,
since hilly areas are generally less well served by roads and are fur-
ther from market centers. Also, mechanization is expected to be less
efficient in hilly areas where the intercropping of barley with maguey
is practiced. Farm size has been another important variable in many
adoption studies. It may be a proxy for a number of factors, such as
economies of scale of use of new technologies (particularly mechanical
technologies), economies of scale in acquiring information, ability to
take risks, and access to capital and inputs. In dividing by farm

SWith a bivariate dependent variable (i.e. two values representing
nonadoption and adoption) error terms are biased in a standard re-
gression. Logit analysis with maximum likelihood estimation fol-
lowing Nerlove and Press (1973) overcomes this problem.

size, we followed an earlier study that showed that farmers with less
than 20 ha depended largely on the rental of tractor services, while
larger farmers owned tractors (Byerlee, Harrington, Marko, 1981). Final-
ly, the bank often provides inputs in kind, and hence bank credit is ex-
pected to influence adoption, especially of biochemical components.
To get maximum discriminating power in the logit function, we chose
that survey (1975 or 1980) for which the adoption level of the component
was closest to 50 percent. That is, the 1975 survey data were analyzed
for tractor, combine and variety and the 1980 survey data were used for
drill, herbicide and fertilizer. A logit function was then run for each
technological component using nonadoption/adoption as the dependent var-
iable, and rainfall, topography, farm size and sometimes bank credit as
the independent variables.
Results of the logit analysis are presented in Table 4. In the case
of mechanical components, except for the drill, topography had the
largest effect on adoption levels. The combine is still not used on al-
most half of farms in sloping areas regardless of farm size. Farm size
significantly influenced the adoption of tractors and drills. Only in
the case of a drill does rainfall significantly affect the adoption of a
mechanical component.
As expected, rainfall generally had the largest effect on the adop-
tion of all three biochemical components. Farm size affected the adop-
tion of variety and fertilizer but did not significantly influence herb-
icide use. As hypothesized, bank credit influenced the adoption of var-
iety and also affected fertilizer adoption at the 10 percent level of

Logistic Curves of Adoption Patterns
Logistic curves of cumulative adoption levels over time were fitted
to analyze the adoption path of each farmer subgroup for each technolog-
ical component. The logistic curve is defined as:
At = K/( + ect)
where At is the cumulative percentage of adopters by time t, K is the

Table 4. Estimated Logit Function of Adoption for

Six Technological

Components a

Survey Year

Number of

Farm Size
(0: 20 ha)
(1: >20 ha)


dry )
wet )

(0: slope )
(1: flat )

Credit Use
(1: user )

Tractor Combine

1975 1975

54 54

.34 .13
(2.69)* (1.32)

-.02 .02
.26) ( .24)

.37 .34
(3.52)* (3.93)*

Drill Variety





Herbicide Fertilizer


.27 .29 .14
(2.60)* (2.36)* (1.18)

.26 .40 .38
(2.87)* (3.03)* (3.53)*

.002 .21 .10
(.02) (1.84) ( .97)


* Significant at the 5 percent level; numbers in parenthesis are asymototic

SEstimated change in the probability that a farmer will adopt given a one
unit change in the independent variable, using the logit estimation proce-
dure of Nerlove and Press (1973).

SThe equation for drill is estimated by ordinary least squares because sume
independent variables take only one value for adopters, making logit estima-
tion impossible.






upper bound on percentage adoption,- 6 is the rate at which adoption
occurs and c is the constant term. This curve (see Figure 6) was chosen
because the cumulative adoption path for new technologies generally fol-
lows a similar S-shaped path (Griliches, 1957). The number of adopters
increases slowly at first because only the most progressive and/or less
risk-averse farmers adopt. Then it increases more rapidly as other farm-
ers become aware of the advantages of this technological component and
finally slows down as all farmers who find the component profitable have
adopted. The ceiling, (i.e. 100 percent of adoption) might not be
reached or could be reached rather slowly (Jarvis, 1981).
Using the logistic curve, the adoption pattern can be described by
two parameters from each curve shown in Figure 6. First, we calculated
A, the year in which 20 percent of the farmers had adopted a given prac-
tice. This was arbitrarily chosen as a measure of the time of initiation
of adoption to represent a point where a significant number of farmers
had already adopted.- Second, we determined BC, the number of years
required for 50 percent of the farmers to adopt the practice during the
period of most rapid adoption.
The logistic curve was fitted to each subgroup of farmers depending
on the factors identified in the logit analysis as affecting adoption of
a specific practice at the 20 percent level of significance. Where topo-
graphy and farm size both affected adoption (i.e. tractor and variety),
the sample was divided into large farmers (over 20 ha, most of which are
on flat land), small farmers in flat areas and small farmers in sloping
or hilly areas. This was necessary because of the positive association

-/ K may vary depending on the expected terminal adoption rate. In our
case, all technological components (with the possible exception of
the drill) are expected to be completely adopted in the long run be-
cause of their profitability and hence 100 percent adoption was

SBecause the logistic curve is asymptotic to the X-axis, it is not
possible to estimate the time of initiation of adoption directly.

Figure 6. Logistic Function Representing the Adoption Process







- -- -
< 20 ---- ---

A B Year

A : Initiation of the adoption process (i. e. 20percent of farmers have adopted)
BC: Number of years in which 50percent of farmers adoptduring the period
of fastest adoption

between farm size and flat land.1 No such association was found between
rainfall and topography or rainfall and farm size.
Parameters for the logistic curves are given in Table 5. In addi-
tion, the actual use of the practice in 1975 and 1980 is reported.-
Looking at the time of initiation of adoption for the whole sample, it
is evident that except for the use of a seed drill, mechanical techno-
logical components have been adopted before all three biochemical compo-
nents. However, the rate of adoption for mechanical components is gener-
ally slower than for the biochemical components, indicating the greater
divisibility of the biochemical components. By 1980, the ranking of

SThe sample size in the 1975 and 1980 surveys is too small to allow
a breakdown of large farms by topography. 83 percent of the large
farmers operated on flat land.

2/ Differences between the two sets of results arise from the differ-
ent definitions of adoption noted above, as well as possible uncer-
tainty on the part of farmers about the year in which they first
used a practice.

Table 5. Parameters of the Logistic Function and

in 1975 and 1980

Parameters of Logistic Function
Time of Initiation Rate of
of Adoption Adoption

Actual Use of Practice

(Year in
which first
20% farmers

(Number of years
required for
middle 50% of
farmers to adopt)

Mechanical Components
All farmers
Large farmers
Small farmers/flat land
Small farmers/slopes



All farmers 1967.2 8.6
Large farmers 1963.8 4.6
Small farmers/flat land 1966.7 6.7
Small farmers/slopes 1973.9 n.a
All farmers 1981.6 16.3
Large farmers 1970.0 n.a

Biochemical Components
Improved Varieties
All farmers 1969.1 12.3
Large farmers 1967.6 5.6
Small farmers/flat land 1964.0 11.2
Small farmers/slopes 1977.2 n.a
Wet zone 1964.0 9.6
Dry zone 1975.6 5.4
All farmers 1971.9 9.7
Large farmers 1966.7 n.a
Small farmers 1972.2 8.9
Wet zone 1968.2 7.2
Dry zone 1978.4 n.a
All farmers 1971.6 11.4
Large farmers 1963.9 11.7
Small farmers/flat land 1971.2 6.5
Small farmers/slopes 1977.5 n.a
Wet zone 1969.2 10.3
Dry zone 1975.4 6.5

n.a. not analyzed because of too few observations.



used in





Actual Adoption Levels

adoption for the whole sample was tractor, combine, variety, herbicide,
fertilizer and drill. This is almost identical to the ranking of adop-
tion levels in the 1975 survey.

Adoption Path for Mechanical Technological Components
Tractor use for land preparation was the first component adopted
and preceded combine harvesting by about 10 years. Among both tractor
and combine users, early adopters were large farmers on flat land, fol-
lowed by small farmers on flat land and, finally, small farmers on slop-
ing land. This last group lagged large farmers in adoption by 19 years
for tractors and by 10 years for combines (see Figure 7). It is partic-
ularly significant that early users of tractors (i.e. large farmers)
generally adopted by purchasing a tractor. In both 1975 and 1980, 75
percent of large farmers using tractors were tractor owners. Later adop-
ters are almost entirely renters of machinery services. For example, all
but one farmer who changed from animal to tractor power between 1975 and
1980 adopted through tractor rental. On sloping land, this enabled trac-
tor use among small farmers to increase from 12 percent in 1975 to 82
percent in 1980--a particularly rapid rate of adoption even compared to
large farmers.
Adoption of combines on sloping land was also very rapid, reflec-
ting the high cost of hand harvesting. Again, all farmers who changed
from hand harvesting to combines from 1975 to 1980 adopted by rental.
Many large farmers also adopted combine harvesting through rental--only
42 percent of large farmers owned a combine harvester in 1980. The rent-
al market for combines has also been strengthened by the development of
a national rental market in which combine harvesters from other parts of
Mexico are imported to the area at harvest time. Interplanting of barley
with maguey has prevented the complete change-over to combine harvesting
and kept the adoption rates lower than for tractors. Many farmers, how-
ever, are removing some maguey rows to increase inter-row spacing and
facilitate combine harvesting.
Associated with the adoption of tractors has been an increase in
the intensity of tillage operations. More than twice as many farmers
ploughed early after the previous harvest in 1980 compared to 1975 (Ta-
ble 6). The number of tillage operations also increased slightly between

Figure 7. Logistic Curves for the Adoption of Six Improved Technological Components

Mechanical Components

Large Farmers /0

S Farmers /
S/on Flat
Land Small Farmers
Sn on Slopes

-b 80-
' .


- -

1944 48 52 56 60 64 68 72 76 80


00 A A
80- Large Farmers 0 moll
/ Farmers
0 /on Flat
60 Land /*

20 Farmers
1944 48 52 56 60 64 68 72 76 80


Biochemical Components
Improved Varieties

Wet Zone


A 0
S DryZone

1944 48 52 56 60 64 68 72 76 80


Wet Zone,



I 80-
U -



1944 48 52 56 60 64 68 72 76 80


Actual points used to fit logistic curves are represented by A o0

b 100-
1 80-

. 60-
^ -



0. 60-



Large Farmers


Wet Zone

1944 48 52 56 60 4 '68 72 '76 8'0


Table 6. Timing of Initial Tillage and Total Number of Tillage Operations
by Power Source in 1975 and 1980

Percent of Farmers Doing
Early Initial Tillage a/

Average Nunber of
Tillage Operations


Animal Power

Rented Tractor

Owned Tractor

Whole Sample









a/ October to January.

n.a. not analyzed because of less than 5 observations.

1975 and 1980. In both cases there is a significant positive correlation
between the intensity of tillage operations and the use of a tractor
versus animal power. Also among tractor users, significantly more trac-
tor owners plough early and undertake additional secondary tillage oper-
ations compared to tractor renters, as shown by Table 6. The increase in
timing and intensity of tillage between 1975 and 1980 is due both to a
switch from animal power to use of a rented tractor and an increase in
tractor ownership. Twenty-seven percent of tractor renters in 1975 had
become tractor owners by 1980 (Table 7).

Table 7. Changes in Source of Power Between 1975 and 1980

Power Source in 1980

Animal Power(percent)

Rented Tractor(percent)

Owned Tractor(percent)


Power Source in 1975

Animal Rented Owned
Power Tractor Tractor

(Percent Farmers)





Finally, adoption of seed drilling in place of broadcasting lagged
compared to the other mechanical components. By 1980, only 13 percent of
farmers used a drill, and this was almost entirely confined to large
farmers in wetter areas. This result is in agreement with our prediction
that based on the low cost of hand broadcasting of seed, drilling would
only be profitable for large fanners wishing to ensure timely planting.

Adoption Path for Biochemical Technological Components
Within the biochemical group of technological components, the use
of improved varieties was generally the first practice to be adopted.
However, its adoption lagged behind that of mechanical practices, par-
ticularly tractor use. By 1980, improved varieties had been adopted by
nearly all farmers in the wet zone. Small farmers lagged large farmers
in adoption, but the lag was less than in the case of tractor use. Im-
proved varieties have also been adopted very rapidly in the dry zone,
but with a substantial lag in initiation of adoption compared to the wet
zone. In 1980, 61 percent of farmers used improved varieties in the dry
zone compared to only 29 percent in 1975. These results accord with the
data from on-farm experiments, which indicate that use of improved var-
ieties is the most profitable and least risky of the biochemical compo-
nents. Widespread adoption of improved varieties by both small and large
farmers has also been aided by their relatively simplicity and low ini-
tial capital cost.
Use of improved varieties has been closely followed by adoption of
herbicide and fertilizer, but the pattern is somewhat different between
the wet and dry zone. In the wet zone, herbicide adoption leads the use
of fertilizer and was also adopted more rapidly. As with other prac-
tices, large farmers adopted earlier than small farmers, although the
lag is small in the case of herbicide. This is most apparent in the
adoption pattern in the 1979 large sample in the wet zone shown in Fig-
ure 8. For both farm size groups, herbicide leads fertilizer in adop-
tion. These results correspond to the higher returns, lower risks and
lower initial capital costs of herbicide relative to fertilizer. The
greater lag in the adoption of fertilizer by small farmers may reflect
the problems of availability of this input.

Figure 8. Adoption Curves for Herbicide and Fertilizer for the 1979 Farmer Survey in the Wet Zone

90- (Small Farmers)
^ Herbicide
80 (Large Fa(Smal Frmers)
70- Fertilizer
(Large Formers)

50- Time of Initiation Rate of Adoption
of Adoption
n (No. of years required
S 40- (year in which first for middle 50% of
H20% farmers adopted) farmers to adopt)
Large Farmers 1964.8 5.2
20- Small Farmers 1968.5 6.6
10- Large Formers 1965.4 7.3
Small Farmers 1971.1 6.0

1960 62 64 66 68 70 72 74 76 78 80

In the dry zone, fertilizer has been more rapidly adopted than
herbicide, although both practices were still used by a small proportion
of farmers in 1980. The earlier adoption of fertilizer relative to herb-
icide in this zone does conform to results from the on-farm experiments,
which indicate high but risky returns from fertilizer use relative to
herbicide use. However, the small number of observations available from
on-farm experiments and the low adoption rates prevent us from drawing
definite conclusions. Furthermore, some farmers counted in the adoption
curve had used fertilizer often within a package provided by the offi-
cial credit bank, but were not using fertilizer in 1980.

Technological Packages versus Step-wise Adoption
From the on-farm experimental results, it appeared that although
there are positive interactions between the biochemical components,
these interactions should not prevent the adoption of each component in
a step-wise manner, especially if farmers follow a sequence of variety-
herbicide-fertilizer. In fact, in no case did a farmer adopt all three
biochemical components in the same year and only about 20 percent of
farmers adopted two components together--usually herbicide and fertil-
izer (Table 8). Furthermore, among farmers using all three components of

the package, the average lag from adoption of the first to the last com-
ponent was nearly five years.

Table 8. Adoption Sequence of Biochemical Technological Camponents
for Individual Farmers in the Wet Zone
1979 1980
Survey Survey
Percent of farmers using at least
one biochemical component who
variety before herbicide and fertilizer n.a. 68
herbicide before variety n.a. 14
fertilizer before variety n.a. 9
variety and herbicide in the same year n.a. 5
variety and fertilizer in the same year n.a. 0
herbicide and fertilizer in the same year n.a. 18
all three biochemical components in the
same year n.a. 0

Percent of farmers using herbicide
or fertilizer who adopted:

herbicide before fertilizer 51 61
fertilizer before herbicide 23 17
fertilizer and herbicide in the
sane year 26 22

n.a. not available.

As indicated by the logistic curve, variety was the first component
adopted in both the wet and dry zone. The on-farm experimental results
indicated that positive interactions exist between variety, herbicide
and fertilizer use, but that variety alone is still quite profitable,
especially in the wet zone. In fact, 68 percent of farmers using at
least one of the biochemical components had adopted variety first,
usually independently of other biochemical components. The experimental
results also suggested large positive interactions between fertilizer
use and herbicide, but with a feasible adoption path of herbicide fol-
lowed by fertilizer. Again, among farmers in the wet zone who had adop-
ted fertilizer and/or herbicide, more than half used herbicide before
fertilizer and less than one-quarter adopted both in the same year (Ta-
ble 8) Two-thirds of the farmers who used both herbicide and fertil-

S This sequence is not apparent in the dry zone, which also accords
with the low level of interaction found in the on-farm experiments.
However, we are reluctant to draw conclusions because of the small
number of observations in the dry zone.

izer in the 1979 survey, and who adopted fertilizer first, followed
within three years with the use of herbicide. Only one-third of farmers
adopting herbicide first followed with fertilizer use in the same space
of three years. The evidence then clearly points to a step-wise pattern
rather than a package approach to adoption. Even with strong positive
interactions between technological components, individual components can
usually be identified that give high returns when adopted in a step-wise


The present study has clearly documented the adoption pattern fol-
lowed by farmers during a period of rapid technological change. During
this period of 10 to 15 years, most farmers have mechanized the major
operations of land preparation and harvesting and, especially in the
wetter zone, adopted a package of biochemical technological components.
Although the area may not be typical because of its proximity to Mexico
City, which has influenced both the labor and product market, the exam-
ple does illustrate the potential for rapid technological change with
appropriate technologies and economic incentives.
The high and rising relative cost of hand and animal methods has
been a major factor favoring rapid mechanization. The drill is the only
mechanical component that has not been widely adopted, and this reflects
the limited potential for saving labor costs by drilling relative to the
other mechanical components.
Mechanization was first adopted by larger farmers on flat land.
However, small farmers have adopted these technologies rapidly, espe-
cially tractors and combines, after a lag of several years. The active
development of a machinery rental market has been a major factor in ex-
plaining high rates of mechanization among small farmers. In fact, 80
percent of small farmers adopted tractors before biochemical technologi-
cal components, indicating that with development of a machinery rental
market, mechanical components are highly divisible inputs. Topography,
which decreases the efficiency of mechanization on slopes, especially
where barley was intercropped with maguey, was generally a more impor-
tant determinant of mechanization than farm size.

While the major motive for mechanization appears to be the saving
of labor, tractor use in land preparation is also associated with yield
increasing practices, such as early ploughing and increased secondary
tillage. These practices increase with both the change from animal to
tractor power and with the change from tractor rental to tractor owner-
Adoption of the biochemical technological components is most
strongly influenced by rainfall. Adoption in the dry zone, where econo-
mic returns were generally lower and risks higher, considerably lagged
adoption in the wet zone. The adoption sequence among the three biochem-
ical components strongly reflects the relative economic returns and
risks to each component. In the wet zone, the sequence followed by farm-
ers was variety-herbicide-fertilizer. Because high economic returns were
closely associated with low risk components, it was not possible to se-
parate the effects of profitability and risk. The order of adoption of
the biochemical components is the reverse of the expected yield increase
from each component.
Although there were strong positive interactions between all three
biochemical components, few farmers adopted more than one component at
the same time. Rather adoption followed a clear step-wise pattern with
components giving highest returns on capital invested being adopted ear-
liest. Hence, farmers over time and in a sequential manner will adopt
the complete package of biochemical components.
The above findings have a number of implications for an efficient
strategy for development and diffusion of improved agricultural technol-
ogies. First, the need to divide farmers into relatively homogeneous
subgroups or recommendation domains for the purposes of research and
extension is illustrated by the results--particularly the sharp distinc-
tion in economic returns, risk, and adoption rate of biochemical compo-
nents between the wet and dry zones. However, definition of these recom-
mendation domains needs to take a long-term perspective. In particular,
after a time lag, small farmers usually followed the same adoption path
as large farmers. The small farmer-large farmer dichotomy, often be-
lieved to require separate research strategies, may not be as important
as comTonly believed, at least for a commercial crop such as the case
analyzed here. The early adoption by large farmers allows experience to

be gained in the use of biochemical technologies by those best able to
take risks. It also allows development of a machinery rental market for
small farmers.
Second, although the research strategy might aim to develop a pack-
age of practices that exploits positive interactions between technolog-
ical components, this package should be a goal for adoption over time
and not for direct extension to farmers. Rather, the research strategy
should seek a step-wise pattern of adopting components in such a way
that each step is both profitable to farmers and appropriate to their
capital constraints. The check plot in each experiment should reflect
existing farmer practice or a projected farmer practice in the future.
In this case study, herbicide trials would be conducted with improved
varieties but without the application of fertilizer. Fertilizer trials
to establish optimal levels of application would be conducted using both
improved varieties and herbicide weed control.
Furthermore, the identification of research priorities should be
based on economic analysis of the likely profitability of each component
rather than potential yield increases. The common strategy of focusing
on "yield constraints" or the "yield gap" would have emphasized research
on fertilizer, which in fact was the last component to be adopted. More-
over, farmers apparently do not need to see large yield increases to be
convinced about adoption of a practice. Improved varieties, which were
adopted first over the whole study area, gave an estimated yield in-
crease of less than 10 percent.
Finally, the private sector has been a major participant in the
diffusion of technologies to farmers in the present case. The private
sector, through machinery distributorships and entrepreneurial farmers,
has largely introduced mechanization and has also, through the associa-
tion of breweries, played a major role in promoting biochemical compo-
nents at least to large farmers. However, the public sector, through the
release of new barley varieties by the research system and the provision
of inputs and credit by the official credit bank, has also been impor-
tant. The public sector, by way of favorable pricing policies, has also
provided strong incentives for technological change. However, we believe
an effective on-farm research and demonstration program in the area,
would have contributed significantly to refining recommendations and

increasing the diffusion rate, especially to small farmers. Even now our
on-farm research results indicate that most farmers could reduce or
eliminate phosphorous application, and that the efficiency of herbicide
use could be increased by more timely application.

Appendix A. Prices, Labor Requirements, and Input Levels Used
in the Economic Analysis of On-Farm Experiments

1975 1980

Labor Requirements
Input Levels

Barley Field Price ($/kg)

Machinery Rental a
Animal power for ploughing ($/ha)-
Disc Plough ($/ha)
Disc Harrow ($/ha)
Drill ($/ha)
Stationery Thresher ($/ha)-
Combine ($/ha)

Wage Rate ($/day)
Labor Costs and Requirements for:
Hand broadcast ($/ha)
Herbicide application ($/ha)
Fertilizer application ($/ha)
Hand harvesting ($/ha)



2 person-days/ha

40 125



.5 person-day/ha
.5 person-day/ha
.5 person-day/ha
5 person-days/ha

Improved Seed ($/kg)
2,4-D as Esteron 47 ($/lt)
Back-pack sprayer rental

Urea ($/kg)
Transport ($/kg)

3 7.5

60 160

50 40



100 kg/ha

.7 It/ha

80 kg of N in wet zone
45 kg of N in dry zone

Capital Cost
(percent per crop cycle)

35 55

/ Two horses without labor and forage costs.
/ Assuming an average yield of 1.7 ton/ha and
n.a. not available.

including transport costs.

Appendix B. Summary of On-Farm Experimental Results, 1976 to 1980

No. of Mean No. of Mean
Observations Yield Observations Yield -
(tTha) (t/ha)
Variety Experiments
Local Variety 15 2.33 9 1.58
Improved Varieties 2.59 1.63
Herbicide Experiments
Without Herbicie 152.08 7 2.18
With Herbicide-' 2.44 2.33
Fertilizer Experiments
Without Nitrogn 22 1.92 12 1.58
With Nitrogen- 2.54 2.14
Variety by Management
Experiments 3 2
Local Variety-Traditional
Management 1.86 .99
Improved Variety-Traditional
Management 1.83 .51
Local Variet 7Improved *
Management-- 2.62 1.43
Improved Var ty-Improved
Management- 3.15 1.12
Herbicide by Fertilizer
Experiments 9 3
Traditional Practce 1.67 1.12
With Herbicide- 1.85 1.36
With Fertilizer- 2.14 *e/ 1.74
With Herbicde and
Fertilizer- 2.65 1.80
Seeding Method Experiments 8
Broadcast 3.16
Drill 2.92
Land Preparation Experiments 2
No disc harrowing 2.57
One disc harrowing 2.93
Two disc harrowings 3.20

Significantly different from check treatment at 5 percent level.
- Does not include lost sites.
-/ Application of 21t/ha of 2,4-D.
- 80 kg/ha of nitrogen in the wet zone and 45 kg/ha of nitrogen in
d/ the dry zone.
Application of both herbicide and fertilizer as specified in footnote
e/ b and c.
/ Significant differences also exist if herbicide alone and fertilizer
alone treatments are compared to application of both herbicide and

Appendix C.

Parameters of the Logistic Curve Estimated
Estimated by Least Squares Regression


Mechanical Components
All farmers
Large farmers
Small farmers on flat land
Small farmers on slopes

All farmers
Large farmers
Small farmers
Small farmers

All farmers
Large farmers

on flat land
on slopes

Biochemical Components
Improved Varieties
All farmers
Large farmers
Small farmers on flat land
Small farmers on slopes
Wet zone
Dry zone

All farmers
Large farmers
Small farmers
Wet zone
Dry zone

All farmers
Large farmers
Small farmers on flat land
Small farmers on slopes
Wet zone
Dry zone

- 9.9













t-value No. of Ob-
served Years














Bolton, F.E. "Agronomic Yield Constraints in Rainfed Cereal Production
Systems." Paper prepared for the Fifth Regional Cereals Workshop,
Algeria, 5-9 May, 1979.

Byerlee, D., L. Harrington, and P. Marko. Farmer's Practices, Produc-
tion Problems and Research Opportunities in Barley Production in
the Calpulalpan/Apan Valley, Mexico. Economics Working Paper No.
81/5, CIMMYT, Mexico, 1982.

Byerlee, D., and L. Harrington. "New Wheat Varieties and the Small
Farmer." Paper presented at the International Conference of
Agricultural Economists, Djakarta, 24 Aug. 4 Sept., 1982.

Byerlee, D., and D. Winkelmann. Accelerating Wheat Production in Semi-
Arid Developing Regions: Economic and Policy Issues. Economics
Working Paper No. 81/2, CIMMYT, Mexico, 1980.

Byrnes, K. J. "Diffusion and Adoption of Innovations in Fertilizers-Re-
lated Agricultural Production Technology in Developing Countries."
Unpublished Report, International Fertilizer Development Center,
Muscle Shoals, U.S.A., 1982.

Eberhart, S. A., and W.A. Russell. "Stability Parameters for Comparing
Varieties." Crop Science 6(1966):36-40.

El Hurani, M. H. "Jordanian Farmers' Perceptions of Improved Wheat
Technology." In: Improving Dry-Land Agriculture in the Middle East
and North Africa. Food Research Institute, Stanford University and
The Ford Foundation Middle East Regional Office, Cairo, Egypt,

Feder, G. Adoption of Agricultural Innovations in Developing Countries:
A Survey. World Bank Staff Working Paper No. 444, Washington, 1981.

Griliches, Z. "Hybrid Corn: An Exploration in the Economics of Techno-
logical Change." Econometrica. 25(1957):501-523.

Hayami, Yujiro, and Vernon W. Ruttan. Agricultural Development; An In-
ternational Perspective. The John Hopkins Press, Baltimore, USA,

Jarvis, L.S. "Predicting the Diffusion of Improved Pastures in Uruguay."
Amer. J. Agr. Econ. 63(1981):495-502.

Mann, C.K. "Factors Affecting Farmers' Adoption of New Production Tech-
nology: Clusters of Practices." Paper prepared for the Fourth Re-
gional Winter Cereals Workshop-Barley, Aman, Jordan, 24-28 April,

Mann, C.K. "Modernization of Turkish Agrichulture." Paper presented at
the International Conference of Agricultural Economists, Djakarta,
24 \Au. 4 Sept., 1982.

Masson, P. "Analysis Agronomique et Economique des Essais CIMMYT-IDGC
1980-81." Unpublished paper, Economics Program, CIMMYT, Mexico,

Perrin, R. K., D. L. Winkelmann, E. R. Moscardi, and J. R. Anderson.
From Agronomic Data to Farmer Recommendations: An Economics
Training Manual. CIMMYT Information Bulletin No. 27, Mexico, 1976.

Perrin, R. K., and D. L. Winkelmann. "Impediments to Technical Progress
on Small Versus Large Farms." Amer. J. Agr. Econ. 58(1976):888-894.

Rogers, E. M. "Where Are We in Understanding the Diffusion of Innova-
tions?", in Schramn W. and D. Lerner, Communication and Change,
1976: 205-222.

Ryan, J. G., and K.V. Subrahmanyam. "Package of Practices Approach in
Adoption of High-Yielding Varieties; An Appraisal." Economic and
Political Weekly, 1975:A101-A110.



81/1 Kwasi Bruce, Derek Byerlee and G.E. Edmeades, "Maize in the
Mampong Sekodumasi Area of Ghana; Results of an Exploratory Sur-
vey" .

81/2 Derek Bverlee and Donald L. Winkelmann, "Accelerating Wheat Pro-
duction in Semi-Arid Developing Regions: Econcmic and Policy

*81/3 Edith Hesse de Polanco and Peter Walker, "A Users Guide to FASAP
-- A Fortran Program for the Analysis of Farm Survey Data".

*81/4 Alan Benjamin, "An Agro-Econmnic Evaluation of Maize Production
in Three Valleys of the Peruvian Andes".

*81/5 Derek Byerlee, Larry Harrington and Paul Marko, "Farmers' Prac-
tices, Production Problems and Research Opportunities in Barley
Production in the Calpulalpan/Apan Valley, Mexico".

81/6 Larry Harrington, "Methodological Issues Facing Social Scientists
in On-Farm/Farming Systems Research".

*82/1 Larry Harrington, et al., "Maize in North Veracruz State, Mexico
--Farmer Practice and Research Opportunities".

*82/2 Larry Harrington, "Exercises in the Economic Analysis of Agron-
omic Data".

**82/3 J. C. Martinez, "Desarrollando Tecnologia Apropiada a las Cir-
cunstancias del productor: El Enfoque Restringido de Sistemas de

82/4 Robert Tripp, "Data Collection, Site Selection and Farmer Parti-
cipation in On-Farm Experimentation".

82/5 Robert Tripp, "Including Dietary Concerns in On-Farm Research: An
Example from Imbabura, Ecuador".

82/6 Derek Byerlee and Edith Hesse de Polanco, "The Rate and Sequence
of Adoption of Improved Cereal Technologies: The Case of Rainfed
Barley in the Mexican Altiplano".

* Available in English and Spanish
** Available in Spanish only

University of Florida Home Page
© 2004 - 2010 University of Florida George A. Smathers Libraries.
All rights reserved.

Acceptable Use, Copyright, and Disclaimer Statement
Last updated October 10, 2010 - - mvs