Groundnuts (Arachis hypogaea L.) are the second most important legume crops after beans, an important source of protein (23 to 25%), fats/oils (40 to 52%) and carbohydrates (10 to 20 %) and widely grown and consumed in Uganda including the Lake Albert Crescent Zone (LACZ). Due to susceptibility of local varieties to groundnut rosette, National Agricultural Research Organisation (NARO) through the National Semi Arid Resources Research Institute (NaSARRI) developed and released the serenut varieties. Adaptive trials were therefore established in the LACZ, to select the most location specific adapted varieties for promotion in this ecologically diverse zone. Four serenut varieties namely serenut 5, 8, 10 and 14 and a locally grown variety (Red beauty) were planted on three farmers' fields in each of the three sub-ecological areas. Data were collected on total pod dry weight (yield), number of pods and on 100 seed weight. In this study, we show that overall yields of serenut 5, serenut 14, serenut 8 and serenut 10 were highly significantly (P < 0.001) different for all traits measured across the subecological areas. Best yields were recorded from the humid tropical rain forest sub-ecological area where 1900 kg/ha were obtained for serenut 14, 2366 kg/ha for serenut 10, 1763 kg/ha for serenut 8 and 1795 kg/ha for serenut 5. The yields obtained from these varieties were generally worst in the semi-arid sub-ecological area. These serenut varieties are generally adapted to wider environmental conditions although their performance per se was found to be generally inconsistent. This study has also found that among all the varieties tested, Serenut 5 was the best adapted across all the sub-ecologies. Overall, we therefore recommend farmers in this ecologically diverse zone to grow these groundnut varieties with improved growing practices such as timely planting, timely weeding, earthing up and pest and disease management in order to obtain consistent high yields.

Weeds represent one of the major biological constraints to upland rice production in low input agricultural systems. The effects of weeding regimes and rice cultivars on weed growth and rice yield were investigated over three seasons. Four weeding regimes [0 (no weeding control), 1, 2, and 3] and three popular rice varieties (NARIC 2, a local cultivar, and NERICA 4), were tested in 4x3 factorial experiment in a Randomised Complete block with three replicates. The most important weed species recorded were; Biden pilosa, Commelina benghalensis L., Euphorbia hirta L., Micrococca mercurialis Benth., Galisonga parviflora Cav, Sida rhombifolia L., Triumfeta spp, Guizotia scabra, Celocia trigyna, Cyprus rotundus, Panicum Maximum Jacq, and Imperata cylindrica L. Across cultivars, the best weeding regimes for weed control and rice yields were single weeding and weeding twice. Differences among interaction effects between variety and weeding regime were not significant for most traits, except ripening ratio and grain yield in experiment one and experiment two. Across weeding regimes, NERICA 4 out yielded the other varieties in all the three experiments. However, a single well timed hand hoe weeding, together with the use of a cultivar with good adaptation to unfavourable rice growing conditions, such as NERICA 4, would increase land and labour productivity of upland rice-based systems in Uganda.