SOUTHERN JOURNAL OF AGRICULTURAL ECONOMICS DECEMBER 1990
ECONOMIC ANALYSIS OF ALFALFA INTEGRATED
MANAGEMENT PRACTICES
Clement E. Ward, Alan K. Dowdy, Richard C. Berberet, and Jimmie F. Stritzke
Abstract
Integrated pest management (IPM) initially
focused on insect pest control. More recently, IPM
encompasses a broader concept of management, one
which crosses several disciplinary boundaries. This
article reports results of research dealing with four
integrated management decisions for alfalfa (cul-
tivar selection, inset control, weed control, and end-
of-season harvest options).
Key words: integrated pest management (IPM),
alfalfa, cultivar selection, harvest
management, economic returns
Economic research on Integrated Pest Manage-
ment (IPM) has focused both on farm-level impacts
of pest management strategies, and on aggregate
impacts (Rajotte et al.). Numerous analytical tools
and methodologies have been employed (e.g. math-
ematical programming, econometric estimation,
simulation, stochastic dominance, and Bayesian
decision theory, among others). Studies concentrat-
ing on individual management decisions, such as the
need for pest control and how it affects various
aspects of the farm enterprise (e.g. yields, risk, and
profitability), have determined that IPM generally
decreases pesticide use and/or production costs
while increasing net returns (Rajotte et al.).
Alfalfa growers make a variety of management
decisions that affect profitability (including cultivar
selection, fertility program, insect and weed con-
trols, harvest method, and marketing timing). Mc-
Guckin expanded the IPM concept for alfalfa to
include harvest alternatives along with pest manage-
ment. Debertin et al. also included alfalfa manage-
ment practices in addition to pest control. Alfalfa
IPM programs at Oklahoma State University,
developed with research and extension input, have
emphasized integration of pest control and
agronomic aspects of management (Ward 1988),
thereby fitting more closely the broader concept of
IPM than is often apparent in the literature.
The objective of this study was to determine the
economic returns within and between years resulting
from combinations of alfalfa cultivars, end-of-
season harvest methods, as well as insect control and
weed control alternatives. Therefore, effects on al-
falfa yields, forage quality, prices, and production
costs were considered. Experimental agronomic
data collected over a five-year period were analyzed
by binary variable regression.
BACKGROUND AND PREVIOUS WORK
The alfalfa weevil is the most important insect pest
of alfalfa in Oklahoma (Berberetet al. 1980). Losses
result primarily from feeding of larvae during
growth of the first crop in March and April (Berberet
et al. 1981). The timing of larval infestations is
determined by the hatching time of eggs laid by adult
weevils during the winter months. The highest egg
numbers (and subsequent larval infestations) are
typically found in those fields having abundant fall
growth of alfalfa where habitats are favorable for
adults. Winter grazing of alfalfa stands by cattle has
been used as a means of reducing overwintering
habitat for weevils and may result in 50 to 70 percent
fewer eggs being present to contribute to larval
populations in the spring (Senst and Berberet). Ad-
ditionally, some alfalfa cultivars, such as Arc, have
been selected for tolerance to feeding of alfalfa
weevils. These cultivars may reduce the need for
applications of chemical insecticides.
Annual weeds compete with alfalfa for soil
nutrients, moisture, and light (Dowdy). If a full stand
of alfalfa (25 to 30 stems per square foot) is main-
tained, weed interference has minimal effects on
productivity. However, if alfalfa plants are stressed,
as occurs with infestations of weevil larvae, weeds
may gain the competitive advantage. High weed
populations can then reduce alfalfa forage yields and
shorten stand life. Weeds typically have a lower
protein content than alfalfa and some less palatable
weeds reduce forage intake by animals. Thus, high
weed content reduces alfalfa hay quality and price
(Dutt et al.; Ward 1987). Dormant-season herbicide
Qement E. Ward is a Professor of Agricultural Economics, Richard Beiberet is a Professor of Entomology, and Jimmie F. Stritzke is
a Professor of Agronomy at Oklahoma State University; Alan K. Dowdy is a Postdoctoral Researcher, U. S. Grain Marketing Research
Lab, ARS USDA.
Copyright 1990, Southern Agricultural Economics Association.
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