The Economics of Integrated Pest Control in Irrigated Rice: A Case Study from the Philippines

206 Pages·1986·4.463 MB·English

by  Dr. Hermann Waibel (auth.)

CROP PROTECTION
MONOGRAPHS
Editor-in-Chief
1. Kranz, GieBen, Fed. Rep. of Germany
Editorial Board
K. H. Biichel, Leverkusen, Fed. Rep. of Germany
R. E. Frisbie, College Station, TX, USA
1. Palti, Tel Aviv, Israel
R. L. Zimdahl, Fort Collins, CO, USA
CROP PROTECTION MONOGRAPHS
Already published volumes
J. Palti, R. Ausher (Eds.)
Advisory Work in Crop Pest and Disease Management
H. Waibel
The Economics of Integrated Pest Control in Irrigated Rice
Further volumes in preparation
D.P. Singh
Breeding for Resistance to Diseases and Insect Pests
I. Wahl and G. Fischbeck
Role of Wild Relatives in Control of Crop Diseases,
Development of Their Epidemics, and Evolution of Pathogens
Hermann Waibel
The Economics of
Integrated Pest Control
in Irrigated Rice
A Case Study from the Philippines
With 19 Figures and 81 Tables
Springer-Verlag
Berlin Heidelberg New York
London Paris Tokyo
Dr. HERMANN WAIBEL
Thai German Plant Protection Programme (TGPPP)
P.O. Box 9-100
Bangkok 10900, Thailand
and
7077 Alfdorf-Stixenhof
West Germany
ISBN-13:978-3-642-71321-7 e-ISBN-13:978-3-642-71319-4
DOl: 10.1007/978-3-642-71319-4
This work is subject to copyright. AIl rights are reserved, whether the whole or part of the mate
rial is concerned, specifically those of translation, reprinting, re-use of illustrations, broad
casting, reproduction by photocopying machine or similar means, and storage in data banks.
Under § 54 of the German Copyright Law, where copies are made for other than private use, a
fee is payable to "Verwertungsgesellschaft Wort", Munich.
© Springer-Verlag Berlin Heidelberg 1986
Sof tcover reprint of the hardcover 1s t edition 1986
The use of registered names, trademarks, etc. in this publication does not imply, even in the ab
sence of a specific statement, that such names are exempt from the relevant protective laws and
regulations and therefore free for general use.
2131/3130-543210
To myfather
and to my late mother
for their motivation
and to my family
Mila Linda,
Matthias and Christoph
for their patience
~cknowledgements
I am indebted to Prof. Dr. 1. Zeddies, Professor of Agricultural Eco
nomics at the University of Hohenheim, and to Prof. Dr. 1. Kranz,
Professor for Phytopathology and Applied Entomology of Tropical
Agriculture for their continuous help and advice.
During the field study in the Philippines I was supported by nu
merous persons and institutions. To all of them I am indebted for their
personal help and support. I am particularly thankful to Mr. 1. Suman
gil, the Chief of the Crop Protection Division of the Bureau of Plant
Industry. Mr. Mauricio Bayoneta, Acting Chief of the regional Crop
Protection Center in Iloilo deserves my special gratitude for his unself
ish support of my work. I should also like to thank the other members
of the regional Crop Protection Centers from Iloilo as well as the staff
from Pili and Maligaya for the execution of the cooperatively planned
field trials. I am also indebted to the German staff of the Philippine
German Crop Protection Programme, especially to Mr. R. Kaske,
GTZ, for his outstanding and continuous support.
In the technical preparation of this work I was assisted by Mrs.
Agnes Bardoll, Mrs. Barbara Obert-Loercher, Mrs. Karin Althaus
from the Institute of Agricultural Economics, University of Hohen
heim, Mrs. C. Mode translated the text from the German and Miss Su
sanne Koch prepared the figures.
The study was financed in part by the Deutsche Gesellschaft fUr
Technische Zusammenarbeit (GTZ), the German Academic Exchange
Service (DAAD) and the University of Hohenheim. These institutions
deserve my special thanks.
Last but not least I want to thank for their patience and coopera
tion the Filipino rice farmers who were willing to provide their fields
for on-farm trials and to answer questions during interviews. As with
many other researches, it is also likely in this case that the farmers'
contributions to the solutions found in this study were larger than the
researcher's.
The greatest thanks, however, has to go to my wife, Mila Linda,
who had the greatest, although invisible effect on the successful com
pletion of this book and who had to bear the major share of the "social
costs" involved.
HERMANN WAIBEL
Contents
Introduction
Background Conditions and Current Situation
in Irrigated Rice Farming . . . . . . . . . 3
1.1 General Cropping Conditions 3
1.2 Organization of Extension and Crop Protection Services 5
1.2.1 Organizational Structure of the General Extension Service 5
1.2.2 Organizational Structure of the Crop Protection
Service ..... . 6
1.3 The Major Pests of Rice 7
2 Assessment of Crop Loss Due to Pests in
Irrigated Rice Farming . . . . . . . 11
2.1 Assessment of Crop Loss in the Philippines 11
2.1.1 Official Pesticide Evaluation Trials 12
2.1.2 Trials Concerning Higher Levels of Crop Protection
Intensity ................. . 14
2.1.3 Trials Concerning Alternative Pest Control Methods 16
2.1.4 Trials Conducted by the Author ....... . 18
2.1.5 Summary of Crop Loss Assessments in the Rice Crop of
the Philippines ................ . 20
2.2 Crop Loss Assessments by Means of Damage Coefficients 21
2.2.1 Methodology ........ . 22
2.2.1.1 Selection of Exogenous Variables 22
2.2.1.2 Selection of Endogenous Variables 23
2.2.1.3 Determination of the Potential Yield 23
2.2.2 Selection of the Correct Type of Function 24
2.2.3 Presentation of Available Data 29
2.2.3.1 Data for Non-Resistant Varieties 29
2.2.3.2 Data for Resistant Varieties 31
2.2.4 Sorting of Available Data . . . 32
2.2.5 Determination of Damage Coefficients by
Means of Simple and Multiple Regression Analysis 33
X Contents
2.2.5.1 Gre.enhouse and Cage Trials ........ . 34
2.2.5.2 Insecticide Trials .... ........ . 35
2.2.5.3 Results Obtained for Resistant Varieties Using Data
from Field Trials ............. . 40
2.2.5.4 Summarizing Assessment of Findings and Comparison
with the Relevant Extension Recommendations 46
2.2.6 Computation of Crop Losses on the Basis of Infestation Data
and Damage Coefficients . . . . . . . 49
2.2.6.1 Analysis of Pest Development Over Time 50
Non-Resistant Varieties ...... . 50
Resistant Varieties - Untreated Plots 54
Resistant Varieties - Observation Stations 54
2.2.6.2 Results of Crop Loss Computations 59
Non-Resistant Varieties .... 60
Resistant Varieties - Untreated Plots 61
Resistant Varieties - Observation Stations 63
Summarizing Evaluation of Crop Loss Computations 65
3 Bases of Micro-Economic Analysis
of Chemical Crop Protection Measures 66
3.1 Definition of the Concept of Economic Thresholds 67
3.1.1 Entomologists' Definition 67
3.1.2 Economists'Definition 68
3.1.3 Relation Between Economic Damage Threshold
and Control Threshold 70
3.1.3.1 Relation Between the Two Threshold Levels for
Rice Pests 72
3.1.4 Consideration of Mixed Infestations 73
3.1.5 Dynamic Aspects 74
3.1.6 Summary 75
3.2 Methods of Calculation for Economic Analysis
of Crop Protection Measures 75
3.2.1 Analysis of Production Functions 76
3.2.2 Cost and Returns Analysis 78
3.2.3 Systems Analysis Approach 80
3.2.3.1 Bio-Economic Simulation Models 80
3.2.3.2 Decision Theoretic Approach 81
Pay-Off Matrix 82
Theoretical Decision Rules 82
Practical Decision Rules 83
3.2.3.3 Summary and Comparison 85
Contents XI
4 Alternative Crop Protection Strategies in Irrigated Rice
Cultivation: Comparison and Evaluation by Means of
a Computer Model 86
4.1 Description of the Model 86
4.2 Model Assumptions 88
4.2.1 Control Strategies 89
4.2.1.1 Strategies for Granules 89
4.2.1.2 Strategies for Sprays 91
4.2.1.3 Strategies Used by Farmers 92
4.2.1.4 Extension Recommendations 93
4.2.1.5 Other Strategies 93
4.2.2 Effectiveness of Control 93
4.2.2.1 Strategies for Granules 96
4.2.2.2 Strategies for Sprays 96
4.2.2.3 Strategies Used by Farmers 98
4.2.2.4 Extension Recommendations 101
4.2.2.5 Other Strategies 101
4.2.3 Control Costs 102
4.2.3.1 Pesticides 102
4.2.3.2 Labour 103
4.2.3.3 Interest 104
4.2.3.4 Cost of Additional Harvest 104
4.2.4 Socio-Economic Conditions in
the Three Investigation Areas 105
4.2.4.1 Farm and Family Size 105
4.2.4.2 Land Tenure 106
4.2.4.3 Costs and Returns 106
4.2.4.4 Potential Yield 109
4.2.4.5 Crop Prices 110
4.2.4.6 Farm Income Situation and Necessary Minimum Yields 112
4.2.4.7 Liquidity Position 114
4.2.4.8 Opportunity Costs of Cash 115
4.3 Results of the Model Computations 118
4.3.1 Results Computed for the Nueva Ecija Area 121
4.3.1.1 Model Assumptions 121
4.3.1.2 The Optimum Strategy 122
Comparison Between Optimum Strategy
and Farmers' Strategies 125
4.3.1.3 Benefit of the Warning Service 127
4.3.1.4 Benefit of Control Thresholds 131
4.3.1.5 Benefit to Be Derived from Infestation Forecasts 132
XII Contents
4.3.2 Results Computed for the Camarines Sur Area 135
4.3.2.1 Model Assumptions 135
4.3.2.2 The Optimum Strategy 136
Comparison Between Optimum Strategy and
Farmers' Strategies .... 139
4.3.2.3 Benefit of the Warning Service 140
4.3.2.4 Benefit of Control Thresholds 140
4.3.2.5 Benefit ofInfestation Forecasts 143
4.3.3 Results Computed for the Iloilo Area 145
4.3.3.1 Model Assumptions ..... . 145
4.3.3.2 Optimum Strategy and Comparison
with Farmers' . . . . . . . 147
4.3.3.3 Benefit of the Warning Service 149
4.3.3.4 Benefit of Control Thresholds 151
4.3.3.5 Benefit ofInfestation Forecasts 152
4.3.4 Comparative Assessment of Model Results for the
Three Investigation Areas . . . . . . 153
4.3.4.1 Economics of Crop Protection Measures 153
4.3.4.2 Benefit of Information Improvement 157
4.3.4.3 Realizability of Strategies from the Point of View
of the Individual Farm ........ . 160
4.3.5 Possibilities and Practicability of the Control
Threshold Concept ....... . 163
4.3.5.1 Farmers' Methods of Pest Observations
and Decision Criteria ............ 164
4.3.5.2 Farmers' Ability to Interpret Infestation Situations 166
4.3.5.3 Economic Benefit of Currently Existing
Control Thresholds ............. 168
4.3.5.4 Required Reliability of Control Thresholds and Effectiveness
of Control Based on Thresholds 170
Increasing the Effectiveness of Control 171
4.3.5.5 Possibilities ofImproving Threshold Values 173
5 Conclusions 179
5.1 Technical Progress in Control Strategies 179
5.2 Improvement of the Information Basis 180
5.3 A New Basic Concept of Crop Protection 182
Appendix 185
References 190
Subject Index 195