Sweetpotato: Major Pests, Diseases, and Nutritional Disorders

166 Pages·1997·3.59 MB·English

by  T. et al.(eds) Ames

Sweetpotato: Major
Pests, Diseases, and
Nutritional Disorders
T.Ames, N.E.J.M. Smit, A.R. Braun,
J.N. O'Sullivan, and L.G. Skoglund
The International Potato Center (CIP) is a
scientific, nonprofit institution dedicated to the
increased and more sustainable use of potato,
sweetpotato, and other roots and tubers in the
developing world, and to the improved
management of agricultural resources in the
Andes and other mountain areas. CIP is part
of the global agricultural research network
known as the Consultative Group on
International Agricultural Research (CGIAR).
International Potato Center
Apartado 1558
Lima 12, Peru
ISBN 92-9060-187-6
Press run: 1000
Printed in Lima, Peru
August, 1997
Cover: Photo of chlorotic spots with and without purple margins induced
by SPFMV (taken byS. Fuentes).
T.Ames, N.E.J.M. Smit, A.R. Braun, J.N. O'Sullivan, and L.G. Skoglund.
1996. Sweetpotato: Major Pests, Diseases, and Nutritional Disorders.
International Potato Center(CIP). Lima, Peru. 152 p.
1. Sweetpotato - Insect pests. 2. Sweetpotato - Diseases.
3. Sweetpotato-Nutritional disorders. 4. Sweetpotato-Integrated manage-
ment. I. International Potato Center.
C O N T E N TS
Page
Foreword vi i
Acknowledgments vi i i
Introduction 1
Insect Pests of Sweetpotato and Their
Management 3
Storage Root Feeders 4
Sweetpotato Weevils (Cylas spp.) 4
West Indian Sweetpotato Weevil (Euscepes
postfasciatus) 10
Rough Sweetpotato Weevil (Blosyrus sp.) 12
Clearwing Moth (Synanthedon spp.) 14
Peloropus Weevil (Pe/oropus batatae) 1 4
White Grubs 15
Stemborers and Feeders 1 6
Clearwing Moth (Synanthedon spp.) 16
Sweetpotato Stemborer (Omphisia anastomasalis) 1 8
Striped Sweetpotato Weevil {Alcidodes dentipes and
A. erroneus) 22
Sweetpotato Weevils (Cylas spp.) 24
Minor Stemborers and Feeders 25
Peloropus Weevil (Peloropus batatae) 25
Sweetpotato Bug (Physomerus grossipes) 26
Long-Horned Beetle 26
Foliage Feeders 28
Sweetpotato Butterfly (.Acraea acerata) 28
Tortoiseshell Beetles (Aspidomorpha spp. and others) 30
Sweetpotato Hornworm (Agnus convolvuli) 34
Armyworms (Spodoptera eridania, S. exigua, S. litura) 36
Page
Leaf Folders (Brachmia convolvuli, Herpetogramma
hipponalis, and others) 40
Strobiderus Beetle (Strobiderus aequatorialis) 43
Rough Weevil (Blosyrus sp.) 43
Sweetpotato Weevils (Cylas spp.) 43
Minor Leaf Feeders 44
Grasshoppers and Locusts (.Zonocerous variegatus,
the variegated grasshopper and Attractomorpha
psitticina, the slant-faced grasshopper,
and others) 44
Virus Transmitters 46
Aphids (Aphis gossypii and others) 46
Whiteflies (Bemisia tabaci) 48
Mites 50
Erinose caused by Eriophyid mites, Aceria sp. 50
Eriophyesgastrotrichus 50
Natural Enemies 52
Earwigs 53
Spiders 53
Pheidole and Other Predacious Ants 54
Beetles 56
Flies and Parasitic Wasps 58
Viruses 61
Fungal Pathogens (Metarrhizium anisopliae and
Beauveria bassiana) 62
Diseases and Pathogens of Sweet-
potato and Their Management 65
Viral Diseases 66
Sweetpotato Feathery Mottle Virus (SPFMV)
(Aphid-transmitted potyvirus) 66
Page
Sweetpotato Sunken Vein Virus (SPSW)
(Whitefly-transmitted closterovirus) 68
Sweetpotato Virus Disease (SPVD) 69
Sweetpotato Mild Mottle Virus (SPMMV)
(Whitefly-transmitted potyvirus) 70
Other Viral Diseases 71
Bacterial Diseases 72
Bacterial Stem and Root Rot (Erwinia chrysanthemi)!2
Bacterial Wilt (Pseudomonas solanacearum) 1A
Soil Rot (Streptomyces ipomoea) 76
Foliar and Stem Diseases Caused
by Fungi 78
Leaf and Stem Scab (Elsinoe batatas, Sphaceloma
batatas) 78
Alternariosis, Anthracnose, Blight (Alternaria bataticola) 80
Phomopsis Leaf Spot (Phyllosticta Leaf Spot)
(,Phomopsis ipomoea-batatas
(,Phyllosticta batatas)) 82
Minor Leaf Spot Fungi 84
Chlorotic Leaf Distortion (Fusarium lateritium) 86
Fusarium Wilt (Fusarium oxysporum f. sp. batatas) 88
Violet Root Rot (Helicobasidium mompa) 90
Sclerotial Blight and Circular Spot (Sclerotium rolfsii) 92
Black Rot (Ceratocystis fimbriata) 94
Storage Root and Postharvest
Diseases 96
Foot Rot (P/enodomus destruens) 96
Java Black Rot (Lasiodiplodia theobromae [Diplodia
gossypina)) 98
Charcoal Rot (Macrophomina phaseolina) 1 00
Soft Rot (Rhizopus stolonifer, Mucor sp.) 102
Page
Diseases Caused by Nematodes 1 04
Root-Knot Nematode [Meloidogyne spp.) 104
Brown Ring (Ditylenchus destructor, D. dipsaci) 1 06
Reniform Nematode (Rotylenchulus reniformis) 1 08
Lesion Nematode (Pratylenchus spp.) 110
Disorders of Unknown Origin 11 2
Fasciation 112
Nutritional Disorders and Their
Management 1 1 5
Causes of Nutritional Disorders 116
Diagnosing Nutritional Disorders 117
Correcting Nutritional Disorders 118
Nutrient Requirements of Sweetpotato 120
Nitrogen Deficiency 122
Phosphorus Deficiency 1 24
Potassium Deficiency 1 30
Magnesium Deficiency 132
Boron Deficiency 1 34
Iron Deficiency 1 36
Acid Soils and Aluminum Toxicity 138
Salinity 140
Literature Consulted 1 42
About the Authors 1 46
Photo Credits 1 47
Index 148
Foreword
This field guide presents information on common pests,
diseases and nutritional disorders of sweetpotato. It is
intended primarily as a tool for correct identification of
these problems and ailments, as an essential first step
in their control.
The principal entries in the guide are accompanied
by photographs orillustrations, and pinpointwherespecific
problems occur. Additional information is provided on
symptoms and recommended control practices, with
emphasis on integrated crop management.
We believe that researchers, extension agents, stu-
dents and farmers alike will find this guide useful, as
it can assist them in controlling pests and diseases while
safeguarding the natural environment needed for sus-
tainable agriculture.
Wanda Collins
Deputy Director General for Research
International Potato Center
Acknowledgments
The information on nutritional disorders of sweetpotato
presented in this field guide was derived from a research
project of the Australian Centre for International Agricultural
Research (ACIAR). The author of the section on nutritional
disorders, J.N. O'Sullivan, is a member of the project based
at the University of Queensland, Australia.
We would like to thank virologist Richard W. Gibson
of the Natural Resources Institute for contributing to the
section on virus diseases.