No abstract

Groundnut rosette virus disease is the most destructive disease of groundnut in Sub-Saharan Africa, Uganda inclusive. Over the past years, a wide range of management options for this disease have been developed and recommended for farmers in Uganda. Relevant efforts have also been made by researchers in disseminating improved technologies to farmers in several parts of the country. However, questions on the extent to which farmers are currently utilizing these technologies and their effectiveness in controlling the disease in their fields remain unanswered. This study aimed at assessing the effect of farmers' practices on the severity patterns of groundnut rosette virus disease in Uganda. A survey was conducted within five agro-ecological zones in Uganda to obtain information on the various practices farmers employ in the management of the crop and disease in their fields using a structured questionnaire. Disease severity was scored in each farmer's field. Farmers were found to be employing a range of practices in groundnut production, including: early sowing, intercropping, use of improved groundnut genotypes, crop rotation; and uprooting and burning diseased plants among others. However, only two management practices: early sowing and use of improved varieties were found to significantly (P<0.05) reduce rosette severity in groundnut fields. Special consideration should therefore be given to these two GRVD management strategies while developing and promoting management packages for this disease.

Urban and peri-urban farming has a potential to address challenges related to food insecurity among city and town dwellers. It provides the urban population with food, nutrition and a source of income and employment, thus reducing on poverty and food scarcity. It has the advantage of proximity to urban markets which saves on transportation costs, thereby increasing farmers' profitability. This study was carried out to establish the current characteristics and trends of urban and peri-urban crop farming in Central Uganda. To accomplish this, a household survey was conducted in Kampala, Wakiso and Masaka districts, Central Uganda. A total of 297 farming households were interviewed on a number of aspects including cropping practices, income sources, home gardening techniques, marketing, irrigation and household waste management. Focus group discussions were also held in each district. Cropping activities were found to contribute on average 40% to the income of farming households, complementing other livelihood sources such as transport business, livestock production, formal employment and other trade. The major crops grown were vegetables, maize, beans, bananas and avocado. A number of home gardening techniques were identified among farmers, for instance, growing crops on food towers, in buckets and bags (sacks). Irrigation and fertilizer application were practiced by 60% of households, mainly on vegetables. Sixty-four percent of the households recycled waste and of these, 75% converted kitchen waste into manure for crop production. We recommend farmers' training on use of household biodegradable waste in home gardening for improved nutrient use efficiency, economical irrigation water management strategies, and other agronomic and marketing aspects of crops that are commercially viable in urban areas, particularly horticultural crops.

Efficient breeding and selection of superior genotypes requires a comprehensive understanding of the genetics of traits. This study was aimed at establishing the general combining ability (GCA), specific combining ability (SCA), and heritability of sweetpotato weevil (Cylas spp.) resistance, storage root yield, and dry matter content in a sweetpotato multi-parental breeding population. A population of 1,896 F1 clones obtained from an 8 × 8 North Carolina II design cross was evaluated with its parents in the field at two sweetpotato weevil hotspots in Uganda, using an augmented row-column design. Clone roots were further evaluated in three rounds of a no-choice feeding laboratory bioassay. Significant GCA effects for parents and SCA effects for families were observed for most traits and all variance components were highly significant (p ≤ 0.001). Narrow-sense heritability estimates for weevil severity, storage root yield, and dry matter content were 0.35, 0.36, and 0.45, respectively. Parental genotypes with superior GCA for weevil resistance included “Mugande,” NASPOT 5, “Dimbuka-bukulula,” and “Wagabolige.” On the other hand, families that displayed the highest levels of resistance to weevils included “Wagabolige” × NASPOT 10 O, NASPOT 5 × “Dimbuka-bukulula,” “Mugande” × “Dimbuka-bukulula,” and NASPOT 11 × NASPOT 7. The moderate levels of narrow-sense heritability observed for the traits, coupled with the significant GCA and SCA effects, suggest that there is potential for their improvement through conventional breeding via hybridization and progeny selection and advancement. Although selection for weevil resistance may, to some extent, be challenging for breeders, efforts could be boosted through applying genomics-assisted breeding. Superior parents and families identified through this study could be deployed in further research involving the genetic improvement of these traits.