Tropical Root and Tuber Crops: Cassava, Sweet Potato, Yams and Aroids (Agriculture)

Most of the world's poorest smallholders depend on tropical roots and tubers crops as their principal source of food and nutrition. These species produce large quantities of dietary energy and have stable yields under difficult environmental conditions. The most important crops are cassava, sweet potato, yam and the aroids, sharing important common traits such as bulkiness, post-harvest perishability and vegetative propagation. This book compiles the most up to date information on the origin, genetics, physiology, agronomy, pests and diseases and post harvest processing of these crops, while attempting to provide ideas for further research and development. CONTENTS......Page 6 ACRONYMS AND ABBREVIATIONS......Page 14 PREFACE......Page 16 SECTION I: CASSAVA......Page 22 Domestication......Page 24 Discovery of the Crop by Western Explorers......Page 28 Present Geographical Distribution......Page 30 Classification......Page 34 Morphological Description of M. esculenta Crantz......Page 35 Related Species......Page 39 Cytology......Page 40 Objectives and Selection Criteria......Page 42 Sexual Reproduction and Sterility......Page 43 Crossing Techniques and True Seed Production......Page 44 Selection Methods and Programmes......Page 46 Heritability of Major Traits......Page 49 Genotype × Environment Interactions......Page 52 Use of Related Species......Page 53 Rapid Vegetative Propagation......Page 54 Use of Molecular Markers......Page 56 Transgenic Technologies......Page 57 Germplasm Conservation......Page 58 Growth Cycle......Page 60 Temperature......Page 65 Nutrition......Page 66 Water Deficit and Stress......Page 67 Yield Potential......Page 68 Soil Preparation......Page 70 Propagule Selection and Preparation......Page 71 Plant Densities and Crop Establishment......Page 73 Intercropping......Page 75 Weeding......Page 77 Fertilization and Nutrient Disorders......Page 78 Harvesting......Page 81 Pests......Page 84 Bacteria......Page 88 Fungi......Page 90 Viruses......Page 92 Integrated Pest and Disease Management......Page 96 Chemical Composition......Page 98 Physiological Disorders in Freshly Stored Roots......Page 99 Marketing and Quality Standards......Page 101 Storage Methods......Page 102 Traditional Processing Techniques......Page 104 Industrial Processing......Page 106 SECTION II: SWEET POTATO......Page 110 Domestication......Page 112 Discovery of the Crop by Western Explorers......Page 114 Present Geographical Distribution......Page 118 Morphological Description of Ipomoea batatas (L.) Lam......Page 120 Related Species......Page 123 Cytology......Page 125 Objectives and Selection Criteria......Page 128 Sexual Reproduction, Incompatibility and Sterility......Page 129 Crossing Techniques and True Seed Production......Page 131 Selection Methods and Programmes......Page 132 Heritability of Major Traits......Page 136 Genotype × Environment Interactions......Page 139 Use of Related Species......Page 140 Rapid Vegetative Propagation......Page 141 Use of Molecular Markers......Page 143 Transgenic Technologies......Page 144 Germplasm Conservation......Page 146 Growth Cycle......Page 148 Photoperiodism......Page 151 Temperature......Page 152 Nutrition......Page 154 Water Deficit and Stress......Page 155 Yield Potential......Page 157 Soil Preparation......Page 160 Propagule Selection and Preparation......Page 161 Plant Densities and Crop Establishment......Page 163 Intercropping......Page 164 Weeding......Page 165 Fertilization and Nutrient Disorders......Page 166 Harvesting......Page 170 Pests......Page 172 Nematodes......Page 177 Bacteria......Page 179 Fungi......Page 181 Viruses......Page 184 Integrated Pest and Disease Management......Page 186 Chemical Composition......Page 188 Marketing and Quality Standards......Page 192 Storage Methods......Page 193 Traditional Processing Techniques......Page 195 Industrial Processing......Page 198 SECTION III: YAMS......Page 202 Domestication......Page 204 Discovery of the Crop by Western Explorers......Page 208 Present Geographical Distribution......Page 209 Classification......Page 212 Morphological Description of Major Cultivated Dioscorea spp.......Page 214 Related Species......Page 227 Cytology......Page 228 Objectives and Selection Criteria......Page 232 Sexual Reproduction and Sterility......Page 234 Crossing Techniques and True Seed Production......Page 235 Selection Methods and Programmes......Page 237 Heritability of Major Traits......Page 239 Genotype × Environment Interactions......Page 240 Use of Related Species......Page 241 Rapid Vegetative Propagation......Page 242 Use of Molecular Markers......Page 244 Transgenic Technologies......Page 246 Germplasm Conservation......Page 247 Growth Cycle......Page 250 Photoperiodism......Page 253 Nutrition......Page 256 Water Deficit and Stress......Page 257 Yield Potential......Page 258 Soil Preparation......Page 260 Propagule Selection and Preparation......Page 262 Plant Densities and Crop Establishment......Page 264 Weeding......Page 267 Fertilization and Nutrient Disorders......Page 269 Harvesting......Page 271 Pests......Page 274 Nematodes......Page 275 Fungi......Page 277 Viruses......Page 281 Integrated Pest and Disease Management......Page 284 Chemical Composition......Page 286 Physiological Disorders in Freshly Stored Tubers......Page 289 Marketing and Quality Standards......Page 290 Storage Methods......Page 291 Traditional Processing Techniques......Page 293 Industrial Processing......Page 295 SECTION IV: AROIDS......Page 298 Domestication......Page 300 Discovery of the Crop by Western Explorers......Page 302 Present Geographical Distribution......Page 303 Classification......Page 306 Morphological Descriptions of Major Aroids......Page 307 Cytology......Page 319 Objectives and Selection Criteria......Page 322 Sexual Reproduction and Sterility......Page 323 Crossing Techniques and True Seed Production......Page 324 Selection Methods and Programmes......Page 327 Heritability of Major Traits......Page 329 Genotype × Environment Interactions......Page 330 Polyploidy Breeding......Page 332 Rapid Vegetative Propagation......Page 333 Use of Molecular Markers......Page 334 Germplasm Conservation......Page 336 Growth Cycle......Page 340 Photoperiodism......Page 343 Temperature......Page 344 Nutrition......Page 345 Water Deficit and Stress......Page 346 Yield Potential......Page 347 Soil Preparation......Page 350 Propagule Selection and Preparation......Page 351 Plant Densities and Crop Establishment......Page 352 Weeding......Page 354 Fertilization and Nutrient Disorders......Page 355 Harvesting......Page 357 Pests......Page 360 Nematodes......Page 363 Fungi......Page 364 Viruses......Page 369 Integrated Pest and Disease Management......Page 370 Chemical Composition......Page 372 Marketing and Quality Standards......Page 375 Storage Methods......Page 376 Traditional Processing Techniques......Page 378 Industrial Processing......Page 379 REFERENCES......Page 382 A......Page 426 C......Page 427 D......Page 428 H......Page 429 M......Page 430 P......Page 431 R......Page 432 T......Page 433 Z......Page 434

Most of the world's poorest smallholders depend on tropical roots and tubers crops as their principal source of food and nutrition. These species produce large quantities of dietary energy and have stable yields under difficult environmental conditions. The most important crops are cassava, sweet potato, yam and the aroids, sharing important common traits such as bulkiness, post-harvest perishability and vegetative propagation. This book compiles the most up-to-date information on the origin, genetics, physiology, agronomy, pests and diseases and postharvest processing of these crops, while attempting to provide ideas for further research and development.

Most of the world's poorest smallholders depend on tropical roots and tuber crops as their principal source of food and nutrition. This book compiles information on the origin, genetics, physiology, agronomy, pests and diseases and post harvest processing of these crops, while providing ideas for further research and development