ABSTRACT

Insecticidal potency of Piper guineense, AzadirachIa indica Capiscum annum. and combinations of these against Callosobruchus maczilatus (Coleoptera 13ruchus) were investigated .in the present research work. Acetone, ethanol ,water and saline extrac these plants as well as their powder were incubated singly and in combination with cowpea seeds infested with C. maculatus for a period of 1 80- 360 days. Test samples were monitored for the number of eggs laid, mortality of adult insect, number of insect emergence hole on cowpea seeds, residual toxicity's of the plant products and their possible synergistic effects. The optimal incubation temperature that would prevent the emergence of C.maculatus adults was also determined. Results obtained showed that acetone extracts of P.guineense, A. indica and c.annum were more effective in preventing oviposition than ethanol, water and saline extracts or their correspondi rg powder. Addition of test doses of these plant product powders offers up to 90 to 150 days protection to the seeds (less than 3 emergence holes per seed and less than 3 progenies per seed). However, treatment of seeds with acetone and ethanol extracts of plant products offered better protection to the seeds against the cowpea weevil than the powders. Treatment of seeds by incubation at 550 C for 6h after eggs have been laid on them Were found to preveñ the emerger o du1 t progenies. Cowpea seeds treated with ethanol extract of the combination plant products showed significantly reduced progeny emergence and insect emergence holes despite the fact that this treatment did not significantly affect the number of eggs laid when compared with the other treatments (single plant product ethanol extract).

TABLE OF CONTENTS

Title page

Certification ii

Dedication iii

Acknowledgement iv

Table of contents v-xi

List of Tables ix

List of Figures xii

Abstract xiii

CHAPTER 1: INTRODUCTION

1.1 Statement of the problem 4

1.2 Justification S

1.3 Objectives 6

1.3.1 Majorobject 6

1.3.1 Specific objectives 6

CHAPTER 2: LITERATURE REVIEW 7

2.1 Taxonomy 7

2.2 Center of Origin Distribution of Cowpca 7

2.3 The Cowpea Seed 8

2.4 Use of Resistant cultivars for Genetic Improvement 9

2.5 Seed and pod —Resistant lines 10

2.6 The Importance of Cowpea 11

2.7 Consumption Pattern of Cowpeas 12

2.8 Nutrition value of cowpeas 13

2.9 Cowpea in Nigerian Diet 14

2.10 Effect of Some Processing Method on Cowpea Utilization 16

2.10.1 Soaking. I 6

2.10.2 Dehulling 16

2.10.3 Germination (Sprouting) 17

2.10.4 High temperature treatment 17

2.10.5 Proper Storage 17

2.10.6 Alkaline Treatment 18

2.10.7 Fermentation 18

2.11 Life History and Behaviour of Cowpea (C. maculalits)

2.12 Identification and Distributions of the Cowpea Storage pest 21

2.13 Insects Pest Management 21

2.14 Losses Common with Cowpea Storage Pest 23

2.15 Control of Insect Pest Storage Cowpea 24

2.15.1 Biological Control 24

2.15.2 Solar and other Heat Disinfestation 24

2.15.3 Chemical Control 25

2.15.4 Use of Oil and Botanicals 25

2.15.6 Triple Plastic Bagging 2?

2.15.7 Co-Storage with Ash and other Abiotic Material 27

2.15.8 Use of Phytochemical /Local Biopreservalive 28

2.16 Seeds Viability 29

2.17 Seed Taint 30

2.18 Efficacy arid Safety 30

2.19 Azadirachta indica (eem) 31

2.19.1 Commercial Application 33

2.20 Piper guineense 33

2.21 Capiscum annum 34

CHAPTER 3: MATERIALS AND METHODS 35

3.1 Procurement of Material 35

3.2 Disinfestation of Cowpea Seeds 35

3.3 Preparation of Plant Products Extracts 35

3.4 Collection! Rearing of insects C.maculaius 36

3.5 Evaluation of the Effects of Pulverized Plant Products 36

3.6 Evaluation of the effects of Plant Products Extracts 37

3.7 Determination of the Affect of Drying Temperature and Drying Time

On progeny Emergence of C.. inaculatus 38

3.8 Determination of moiture Ccontent of Cowpea 38

3.9 Statistical Analysis 39

CHAPTER FOUR: RESULTS AND DISCUSSIONS 4. •

4.1 Effect of Treatment with Plant Products on Oviposition, Emergence

hole and Progeny emergence on Cowpea seeds by C'. maculatus.

4.1 .1 Effect of Acetone Extracts of the Plant Products on eggs laid by C'. maciilatus

4.1.2 Effect of Ethanol Extracts of the Plant Products on eggs laid by (7. macn/at us 44

4.1.3 Effect of Water Extracts of the Plant Products on eggs laid by C.maculaIus

4.1.4 Effect of Saline Extracts of the Plant Products on eggs laid by C'. maculatus

4.1.5 Effect of treatment of the plant products on eggs laid by C.maculaius

4.2 Effect of Treatment with Plant Products on Percentage (%) 1)aily mortality of

C.maculutus versus Period at ig powder lOg Cownea.

4.3 Effects of Incubation Temperature on C'. maculatus

CHAPTER 5: CONCLUTION AND RECOMMENDATIONS

REFERENCES

APPENDICES