Search results for: sweetpotato

Authors: Jerah Mystica B. Novenario, Flor A. Ceballo-Alcantara

Abstract:

Sweetpotato is grown in tropical countries for its edible tubers, which became an important source of food. It is usually propagated through vine cutting which may be obtained from harvested plants or from nurseries intended for cutting production only. The recurrent use of vines may cause increased weevil infestation. The crop is known to be infested with insect pests, more importantly, the sweetpotato weevil, Cylasformicarius, which targets the tubers and thus cause economic losses. Sweetpotato farmers in Tarlac claim that only one sweetpotato cultivar is being attacked by C. formicarius. However, in was found in this experiment that feeding and feeding behavior of the weevil were not affected by the cultivar provided; such that no significant differences were observed on the average amount of tuber consumed by both male (F=0.86; df=2; P=0.45) and female (F=2.71; df=2; P=0.11) and feeding time (F=0.9; df=2; P=0.43). Conversely, in terms of damage assessment, significantly different (F=1.64; df=2; P=0.23) results were noted.

Keywords: cylas formicarius, feeding behavior, insect pest, sweetpotato

Procedia PDF Downloads 55

Authors: John Saaka

Abstract:

The increasing world population poses a threat to food security. To meet current and future food demands, sweetpotato stand a good chance because of its recent food security roles. Concerted efforts are needed for both regional and local level varietal development. Heterosis exploiting breeding scheme (HEBS) is one of the options used to improve yield in some crop species and could be a good approach for sweetpotato improvement in Ghana by establishing heterotic gene pools within a population. To achieve this, 22 parental lines were collected from different sources and put in a full diallel arrangement. A total of 149 families, 20 individual cuttings per family, were taken to the field, including ‘checks’ and parental lines for experimentation in a 1m X 0.3m planting order according to the Westcott design. Results from this study led to the characterization of the selected parents into three main heterotic gene pools based on their suitability for use as male, female or both, respectively. This study serves as a baseline for further characterization of the rest of the germplasm in the Ghanaian sweetpotato breeding program.

Keywords: sweetpotato, heterosis, germplasm, food security

Procedia PDF Downloads 34

Authors: Dernie Taganna Olguera

Abstract:

Marginal uplands are fragile ecosystems in the tropics that need to be evaluated for sustainable utilization and land degradation mitigation. Thus, this study evaluated the dominant soil degradation processes in selected marginal uplands of Samar Island, Philippines; evaluated the important factors influencing soil degradation in the selected sites and identified the indicators of soil degradation in marginal uplands of the tropical landscape of Samar Island, Philippines. Two (2) sites were selected (Sta. Rita, Samar and Salcedo, Eastern, Samar) representing the western and eastern sides of Samar Island respectively. These marginal uplands represent different agro-climatic zones suitable for the study. Soil erosion is the major soil degradation process in the marginal uplands studied. It resulted in not only considerable soil losses but nutrient losses as well. Soil erosion varied with vegetation cover and site. It was much higher in the sweetpotato, cassava, and gabi crops than under natural vegetation. In addition, soil erosion was higher in Salcedo than in Sta. Rita, which is related to climatic and soil characteristics. Bulk density, porosity, aggregate stability, soil pH, organic matter, and carbon dioxide evolution are good indicators of soil degradation. The dominance of Saccharum spontaneum Linn., Imperata cylindrica Linn, Melastoma malabathricum Linn. and Psidium guajava Linn indicated degraded soil condition. Farmer’s practices particularly clean culture and organic fertilizer application influenced the degree of soil degradation in the marginal uplands of Samar Island, Philippines.

Keywords: soil degradation, soil erosion, marginal uplands, Samar island, Philippines

Procedia PDF Downloads 371