Storage Practices, Incidence and Economic Losses Caused by the Yam Scale Insect, Aspidiella Hartii Cockerell in Nasarawa State, Nigeria

Yam (Dioscorea species) is an annual root-tuber crop with social and economic significance in terms of food security, cash returns and human health, which has social and economic importance in terms of food, cash and medicine. Insect pests present major constraints to production, storage and marketing resulting in yield and revenue reduction, and deterioration of tuber quality in storage. This study was thus designed to assess yam storage practices by the farmers and the prevalence and economic impacts of the yam scale insect, Aspidiella hartii in selected locations of Nasarawa state, Nigeria. A multi-stage sampling technique was used to select 60 yam farmers from the study area. The first stage involved random selection of four Local Government Areas (LGAs) out of the five in the study area. The second stage was the purposive selection of three villages from each of the selected LGAs while the 3rd stage was random selection of five yam farmers from each of the 12 selected villages who were interviewed using a pretested structured questionnaire. Data collected were analyzed using descriptive statistics. Results showed that the common yam storage structures were open sheds, under tree canopies, and field barns with varied dimension of 5-10 m2. Most respondents (98.3%) affirmed the presence of the yam scale insects on stored yams on those stored in the open, barns and stores, with increased incidence with extended duration in storage. Significant reduction of 36% – 50% in the market value of yam due to infestation of the yam scale insect was reported under all storage conditions. Many respondents (60%) recognized misuse and abuse as consequences of pesticide application thus, creating the need for farmers to adopt more environmentally friendly storage practices for management of the yam scale insect in the study area.