Evaluation of the Sensitivity of Thirteen (13) Promising Cassava Varieties to Diseases (Viruses-Bacteria) and Pests (Mealybugs-Mites) in Central Côte d’Ivoire

Cassava (<i>Manihot esculenta</i>), a plant with starch-rich roots, plays a crucial role in global food security. For producers, it has become both a subsistence and cash crop. In Côte d’Ivoire, it ranks second among crops after yam. However, cassava is severely affected by bacteria, fungi, viruses, mites, and mealybugs, causing yield losses ranging from 20% to 90%. This study was conducted at the Food Crop Research Station (FCRS) of the National Center for Agronomic Research (NCAR) in Bouake in central Côte d’Ivoire. The plant material consisted of thirteen varieties of cassava of the <i>Manihot esculenta</i> species, from the national cassava collection. It aimed to assess the performance of thirteen promising cassava varieties, originating from the national cassava collection, against these diseases and pests under natural infestation conditions. The results revealed that the Yacé variety showed the highest sensitivity to viruses, with an incidence (I) of 96.25% and a severity index (IGS) of 2.8. In contrast, the Yavo variety was the least sensitive, with an incidence of 11.50% and a severity index of 1.3. All varieties studied demonstrated high sensitivity to bacterial blight and mite attacks, with high incidence rates observed in Bocou1 (71.25%) and Bocou3 (68.75%). However, mealybug infestation was relatively low, ranging from 8.75% (Yavo) to 33.75% (Bocou2). Except for mosaic disease, the severity indices for diseases and pests were similar across all varieties.