Post-Harvest Control of Yam Tuber Rot Caused by Rhizopus Oryzae and Botyodiplodia Theobromea Using Leaf Extracts Of Tobacco (Nicotiana Tabacum) and Papaya (Asimina Triloba)

ABSTRACT

Post-harvest microbial rot is one of yam diseases which occurs both in the field and barn. The pathogenic fungi most frequently encountered in this study included: Rihizopus., oryzae and Bolryodiplodia theohroniea. These organisms were isolated from stored yam tubers. They caused soft rot leading to tissue discolouration and production of foul smell from the rotted portion of the tubers. Tubers which were infected with R .oryzae and B. theobromea rotted completely after 14 days of incubation. However, the alcohol extract of tobacco (Nicotiana tabacum) and Papaya Asimina lriiohq) suppressed the growth of the pathogenic fungi, R,. Oryzae and B. Iheobromea in culture and reduced rot development in yam tubers.

TABLE OF CONTENTS

PAGE TITTLE

 Dedication ii

Acknowledgement iii

Abstract iv

Certification V

List of Plates ... vi

List of Tables •.. vii

Table of Contents viii

CHAPTERS '1.

INTRODUCTION 2.

 MATERIALS AND METHOIS 2.1

Sources of Pathogen on Yarn tuber 8 2.2

The Culture Media 8 2.3

Isolation of Pathogen 2.4

Pathogenicity Test II 2.5

Extraction of the plant Materials 12 2.6

Effect of the Extraôt on the radial Growth of the Fungi 2.7

Effect of Extrat oii rot development on tubers I 3.

RESULTS 3.1

The results of the Isolation 1 3.2

Effect of leaf extract on the radial Growth of Rhizojms oryze 1£ 3.3

Effect of leaf Extract on the radial Growth of Boliyodiplodia iheobromea 3.4

Effect of ethanol leaf Extract on rot Development in yarn tubers by R. Oryazae 17 3.5

 Effect of Extract on rot development in Yam tubers by B. iheohroniea 13 4.

DISCUSSION 0 21

 REFERENCES 24-25