Whitefly and whitefly-borne viruses in the tropics : Building a ... - cgiar

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Benin or disease problem, the main methods used were weeding and application of wood ash. Even though no farmer reported the use of resistant varieties as a whitefly/disease control method, further questioning revealed that 8% of farmers listed “Agric” and 5% listed Odounbo as varieties they had planted on the basis of recommendations that they were tolerant to CMD. Twenty percent of these farmers indicated that the better performance of these varieties was mainly because of better sprouting and establishment of the cutting. Agronomic features were more important than pest/disease resistance as criteria for the selection of planting material. About 12% of the selection criteria related to disease-free stems, health of stems and disease resistance, whilst 23% related to size, maturity, better yield, colour and size of the parent stem. Where disease-specific criteria were used for selecting planting material, only 10% of the farmers reported that the method was effective and 7% noticed that the “clean” material became diseased after planting. Because the single most frequently cited sources of planting material were farmers’ own fields (30%) and neighbours’ fields (22%), adoption of appropriate planting material selection would be expected to reduce recycling of CMBs considerably. Whilst no farmer indicated roguing as a specific CMD control method, 7% of them conducted roguing to prevent and reduce disease and 2% because of poor plant growth; 7% of the farmers reported some impact from this control measure. However, the current high incidence of cutting infection would make roguing very labor intensive and unattractive for adoption, unless carried out in combination with the selection of CMD-free planting material. Pesticide use was rare. Conclusions In Africa, cassava root yield losses due to CMD have been estimated at 28%-40% annually (Thresh et al., 1994). In Benin, there appears to be a contradiction between field data and farmers’ perception of the CMD problem. The research data indicate only a very small proportion of cassava plants with moderate or severe disease damage but 25% of the farmers attribute high losses to the disease. In such cases, farmer participatory trials would help farmers and researchers jointly to better understand the relationship between disease incidence and yield, and to validate loss estimates. The studies would help establish whether losses to CMD really are significant in Benin and, if so, convince farmers of the need to adopt integrated management practices against the disease. Such an approach will provide for action learning by farmers to improve their access to information and understanding of the causes and nature of the disease problem. For example, cutting infection was found to be much more important than Bemisia whiteflies in the spread of CMD, suggesting that a participatory learning and extension effort focusing on planting material selection and sanitation and roguing could have a positive impact. Generally, training of national program partners would strengthen the collaborative links established in the pilot phase of the project and further enhance national capacity to undertake priority CMD and whitefly research activities. For example, field studies on the population dynamics of B. tabaci would be needed to understand temporal and spatial changes in the insect’s abundance in relation to its ability to spread CMD. There is also the need to quantify the effectiveness of parasitism by E. sophia, 33
particularly as a possible factor influencing the importance of the vector in spreading CMD. In view of the low abundance of B. afer in the country, it would not be appropriate to commit further resources to investigating its role in CMD epidemiology. 34 References Burban, C.; Fishpool, L. D. C.; Fauquet, C.; Fargette, D.; Thouvenel, J. -C. 1992. Host associated biotypes within West African populations of the whitefly Bemisia tabaci (Genn.) (Hom., Aleyrodidae). J. Appl. Entomol. 113:416-423. Gregory, P. H. 1948. The multiple infection transformation. Ann. Appl. Biol. 35:412-417. IITA (International Institute of Tropical Agriculture). 1998. Ecologically Sustainable Cassava Plant Protection (ESCaPP) in South America and Africa. Africa: Project findings and recommendations. Ibadan, NG. James, B. D.; Legg, J. P.; Gbaguidi, J. B.; Annang, D.; Asiabaka, C. C.; Cudjoe, A. R.; Echendu, T. N. C.; Maroya, N. G.; Ntonifor, N.; Ogbe, F.; Salawu, R. A.; Tumanteh, J. A. 1998. Understanding farm-level epidemiology of cassava mosaic disease. In: Abstracts, 7th Triennial Symposium of the International Society for Tropical Root Crops- Africa Branch (ISTRC-AB), 11-17 October 1988, Cotonou, BJ. p. 122. Whiteflies and Whitefly-borne Viruses in the Tropics Legg, J. P.; Gibson, R. W.; Otim-Nape, G. W. 1994. Genetic polymorphism amongst Ugandan populations of Bemisia tabaci (Gennadius) (Homoptera: Aleyrodidae), vector of African cassava mosaic geminivirus. Trop. Sci. 34:73-81. Legg, J.; James, B. D.; Cudjoe, A.; Saizonou, S.; Gbaguidi, B.; Ogbe, F.; Ntonifor, N.; Ogwal, S.; Thresh, J.; Hughes, J. 1997. A regional collaborative approach to the study of ACMD epidemiology in sub- Saharan Africa. Afr. Crop Sci. J. 3:1021-1033. Sotomey, M.; James, B. D.; Gbaguidi, B. 1995. Les espèces de Bemisia sur le manioc en Afrique occidentale et centrale. In: 11th meeting and scientific conference of the African Association of Insect Scientists, 6-11 August 1995, Yamoussoukro, CI. p. 4. Thresh, J. M.; Fishpool, L. D. C.; Otim- Nape, G. W.; Fargette, D. 1994. African cassava mosaic virus disease: An under-estimated and unsolved problem. Trop. Sci. 34:3-14. Yaninek, J. S.; James, B. D.; Bieler, P. 1994. Ecologically Sustainable Cassava Plant Protection (ESCaPP): A model for environmentally sound pest management in Africa. Afr. Crop Sci. J. 2:553-562.
Page 2 and 3: About the Partners CIAT The Interna
Page 4 and 5: Centro Internacional de Agricultura
Page 6 and 7: Chapter 4 Whiteflies and Whitefly-b
Page 8 and 9: Chapter 6 Whiteflies and Whitefly-b
Page 10 and 11: Contents Page Foreword vii Introduc
Page 12 and 13: Contents Chapter SECTION THREE Whit
Page 14 and 15: Foreword This book is the product o
Page 16 and 17: Introduction Introduction The Probl
Page 18 and 19: Introduction In addition to the yie
Page 20 and 21: Introduction in pesticide use in La
Page 22 and 23: Introduction annual crops, especial
Page 24 and 25: Introduction Plant Resistance contr
Page 26 and 27: Introduction Otim-Nape, G. W.; Bua,
Page 28 and 29: SECTION ONE Whiteflies as Vectors o
Page 30 and 31: Introduction CHAPTER 1.1 Introducti
Page 32 and 33: Introduction diseases than is cassa
Page 34 and 35: Introduction Sub-project on Whitefl
Page 36 and 37: Introduction References Aritua, V.;
Page 38 and 39: Introduction Thresh, J. M.; Otim-Na
Page 40 and 41: Ghana 1997, on 80 farms. These incl
Page 42 and 43: Ghana (6.2%), Bakentenma (5%) and K
Page 44 and 45: Ghana Legg, J. P.; James, B. D. 199
Page 46 and 47: Benin Northern guinea savannah Sout
Page 50 and 51: Nigeria CHAPTER 1.4 Nigeria Introdu
Page 52 and 53: Nigeria TMS 30572 (18.8%) and TMS 3
Page 54 and 55: Nigeria FAO (Food and Agriculture O
Page 56 and 57: Cameroon protocol, to enable valid
Page 58 and 59: Cameroon Farmers undertook various
Page 60 and 61: Cameroon Robertson, I. A. D. 1987.
Page 62 and 63: Uganda between November 1997 and Ja
Page 64 and 65: Uganda environment, host plant heal
Page 66 and 67: Uganda local varieties. Assessments
Page 68 and 69: Uganda Harrison, B. D. 1987. Proper
Page 70 and 71: Kenya Recent epidemiological studie
Page 72 and 73: Kenya respective diseases were reco
Page 74 and 75: Kenya Bock, K. R. 1983. Epidemiolog
Page 76 and 77: Tanzania CHAPTER 1.8 Tanzania Intro
Page 78 and 79: Tanzania Adult whiteflies were more
Page 80 and 81: Tanzania loss) to assess yield loss
Page 82 and 83: Tanzania Legg, J. P.; Raya, M. 1998
Page 84 and 85: Malawi Increased Biological Underst
Page 86 and 87: Malawi Physiology and Ecology in th
Page 88 and 89: Madagascar Tanzania Madagascar Moza
Page 90 and 91: Madagascar surprising, particularly
Page 92 and 93: Diversity of African Cassava Mosaic
Page 98 and 99:
Sweetpotato Virus Disease in East A
Page 100 and 101:
Page 102 and 103:
Page 104 and 105:
Factors Associated with Damage CHAP
Page 106 and 107:
Factors Associated with Damage Mean
Page 108 and 109:
Factors Associated with Damage % SP
Page 110 and 111:
Factors Associated with Damage thro
Page 112 and 113:
Factors Associated with Damage Gedd
Page 114 and 115:
Conclusions and Recommendations col
Page 116 and 117:
Conclusions and Recommendations Mal
Page 118 and 119:
Conclusions and Recommendations Mpi
Page 120 and 121:
Conclusions and Recommendations com
Page 122 and 123:
Conclusions and Recommendations con
Page 124 and 125:
Conclusions and Recommendations (2)
Page 126 and 127:
Conclusions and Recommendations Ger
Page 128 and 129:
SECTION TWO Whiteflies as Pests and
Page 130 and 131:
Introduction CHAPTER 2.1 Introducti
Page 132 and 133:
Introduction Czosnek, H.; Navot, N.
Page 134 and 135:
Sudan cotton, leading to the introd
Page 136 and 137:
Sudan Table 1. Reproductive host pl
Page 138 and 139:
Sudan Historically, Sudan has been
Page 140 and 141:
Sudan Only 10% of producers reporte
Page 142 and 143:
Sudan Conclusions The work conducte
Page 144 and 145:
Kenya CHAPTER 2.3 Kenya Introductio
Page 146 and 147:
Kenya Increased Biological Understa
Page 148 and 149:
Kenya Samples of 10 plants per fiel
Page 150 and 151:
Kenya Table 4. Maximum incidence (%
Page 152 and 153:
Kenya Seventy-nine percent of tomat
Page 154 and 155:
Kenya under Phase 2 of the TWF-IPM
Page 156 and 157:
Tanzania CHAPTER 2.4 Tanzania Intro
Page 158 and 159:
Tanzania The reproductive host plan
Page 160 and 161:
Tanzania Geographical range of whit
Page 162 and 163:
Tanzania Local names given to white
Page 164 and 165:
Tanzania Nono-Womdim, R.; Swai, I.
Page 166 and 167:
Malawi levels of infestation by the
Page 168 and 169:
Malawi Table 3. Maximum incidence (
Page 170 and 171:
Malawi (40%) believe that the white
Page 172 and 173:
Tomato Yellow Leaf Curl Virus in E.
Page 174 and 175:
Page 176 and 177:
Page 178 and 179:
Conclusions and Recommendations CHA
Page 180 and 181:
Conclusions and Recommendations (Fi
Page 182 and 183:
Conclusions and Recommendations Cen
Page 184 and 185:
Conclusions and Recommendations the
Page 186 and 187:
SECTION THREE Whiteflies as Vectors
Page 188 and 189:
Page 190 and 191:
Introduction especially for export.
Page 192 and 193:
Mexico CHAPTER 3.2 Mexico Introduct
Page 194 and 195:
Mexico Culiacán, Sinaloa, in north
Page 196 and 197:
Mexico Table 2. Virus survey of tom
Page 198 and 199:
Mexico results of the molecular bio
Page 200 and 201:
Mexico Strengthened Research Capaci
Page 202 and 203:
Mexico López, R. 1996. Experiencia
Page 204 and 205:
Guatemala 1960s, and at this time t
Page 206 and 207:
Guatemala Table 2. Results of white
Page 208 and 209:
Guatemala Table 5. Cropping systems
Page 210 and 211:
Guatemala contemplated in this prel
Page 212 and 213:
El Salvador CHAPTER 3.4 El Salvador
Page 214 and 215:
El Salvador During the course of th
Page 216 and 217:
El Salvador markets: common bean, m
Page 218 and 219:
El Salvador Current Status of White
Page 220 and 221:
Honduras Copan Ocotepeque Santa Bá
Page 222 and 223:
Honduras Table 3. Biotyping of whit
Page 224 and 225:
Honduras References Caballero, R. 1
Page 226 and 227:
Nicaragua Nueva Segovia Madriz Este
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Nicaragua Lowlands of Nicaragua. Th
Page 230 and 231:
Nicaragua Region VI is a main horti
Page 232 and 233:
Costa Rica CHAPTER 3.7 Costa Rica I
Page 234 and 235:
Costa Rica Table 1. Characterizatio
Page 236 and 237:
Costa Rica Castillo, J. 1997. Movim
Page 238 and 239:
Panama Bocas del Toro Chiriquí Ver
Page 240 and 241:
Panama Gámez, R. 1970. Los virus d
Page 242 and 243:
Haiti Grande-Anse Sud Grande-Anse S
Page 244 and 245:
Haiti collaborators in this project
Page 246 and 247:
Cuba Ciudad de la Habana Pinar del
Page 248 and 249:
Cuba Table 3. Comparative homologie
Page 250 and 251:
Cuba project provided three keynote
Page 252 and 253:
Dominican Republic CHAPTER 3.11 Dom
Page 254 and 255:
Dominican Republic monoclonal antib
Page 256 and 257:
Dominican Republic Strengthened Res
Page 258 and 259:
Reproductive Crop Hosts of Bemisia
Page 260 and 261:
Page 262 and 263:
Page 264 and 265:
Page 266 and 267:
Biotypes of Bemisia tabaci CHAPTER
Page 268 and 269:
Biotypes of Bemisia tabaci For this
Page 270 and 271:
Biotypes of Bemisia tabaci 100 99 B
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Biotypes of Bemisia tabaci biotype
Page 274 and 275:
Biotypes of Bemisia tabaci Table 2.
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Biotypes of Bemisia tabaci Already
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Page 280 and 281:
Conclusions and Recommendations gre
Page 282 and 283:
SECTION FOUR Whiteflies as Pests of
Page 284 and 285:
Page 286 and 287:
Introduction control, due to resist
Page 288 and 289:
Introduction Posada, L. 1976. Lista
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Colombia and Ecuador B biotype B. t
Page 292 and 293:
Colombia and Ecuador assistants and
Page 294 and 295:
Colombia and Ecuador and squash. On
Page 296 and 297:
Colombia and Ecuador Table 2. Main
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Colombia and Ecuador Table 6. Patte
Page 300 and 301:
Insecticide Resistance in Colombia
Page 302 and 303:
Page 304 and 305:
Page 306 and 307:
Page 308 and 309:
Page 310 and 311:
Page 312 and 313:
Conclusions and Recommendations res
Page 314 and 315:
Conclusions and Recommendations rot
Page 316 and 317:
SECTION FIVE Special Topics on Pest
Page 318 and 319:
Sustainable IPM through Host Plant
Page 320 and 321:
Page 322 and 323:
Page 324 and 325:
Page 326 and 327:
Page 328 and 329:
Biological Control of Whiteflies by
Page 330 and 331:
Page 332 and 333:
Page 334 and 335:
Page 336 and 337:
Page 338 and 339:
Page 340 and 341:
Progress of Cassava Mosaic Disease
Page 342 and 343:
Page 344 and 345:
Page 346 and 347:
Page 348 and 349:
Management of the Cassava Mosaic Di
Page 350 and 351:
Page 352 and 353:
Page 354 and 355:
Conclusions Conclusions The Tropica
Page 356 and 357:
Conclusions whitefly pests and thus
Page 358 and 359:
Conclusions developing countries, a
Page 360 and 361:
Acronyms and Abbreviations Acronyms
Page 362 and 363:
Acronyms and Abbreviations FIRA Fid
Page 364 and 365:
Acronyms and Abbreviations PROFRIJO
Page 366:
Acronyms and Abbreviations PYR pyre
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