Exotic mango varieties can improve the livelihood security and increase profitability of mango growers in Uganda. There are however, several factors like pests, diseases and orchard management practices which limit mango production and productivity. The study sought to investigate farmers’ knowledge and perceptions of mango pests and diseases and orchard management practices in West Nile zone (WNZ) of Uganda. Farmers growing exotic mango varieties were selected from six districts namely, Arua, Maracha, Koboko, Yumbe, Moyo and Nebbi in WNZ. Both purposive and simple random sampling techniques were used to identify 90 respondents who were interviewed with a semi structured questionnaire. The data was analyzed both descriptively and inferentially. Chi square tests were used to analyze farmers’ perception on pests and diseases. Multinomial logit was used to analyze factors influencing choice of orchard management practices. The results showed a significant variation in perception of farmers on incidence, severity and yield loss due to various pests (fruit flies, seed borer, termites, scales and mealy bugs) and, diseases (anthracnose, bacterial black spot, powdery mildew, algal leaf spot and sooty mould). Farmers’ choice to take a particular management practice like pruning, spraying, manuring and mulching were influenced by age of mangoes, extension service, education level and sex. It was concluded that many pests and diseases of exotic mangoes existed in WNZ and sound scientific orchard management practices were still lacking among the mango farmers. The study recommended awareness creation on various mango pests and diseases, and capacity enhancement of farmers and extension staff on scientific orchard management practices.

Agriculture depends on the ability of seeds to survive until the next planting season under ambient conditions that may be averse to seed quality even when the seed is in a quiescent state. Seed priming invigorates seeds, but the impact on the longevity of seeds has limited its adoption. This study investigated the effect of the storage of primed rice seed on seed viability, vigor, and longevity. Three seed priming methods were employed on the rice cultivar New Rice for Africa (NERICA 4) seeds. Subsequently, the seeds were stored for 120 days at 25 °C and 65% relative humidity, simulating the ambient seed storage conditions of the tropics and sub-tropics. The primed seed recorded increased vigor compared to the non-primed seed until 90 days of storage. However, seed storage for 120 days reduced seed vigor and viability for all the seeds. The results indicated a significant reduction in seed vigor, increased solute leakage, generation of hydrogen peroxide, and accumulation of malondialdehyde after storage. Priming enhances cell membrane integrity and maintains seed vigor in storage at near ambient conditions long enough before reversal of its performance by the storage conditions. This assures that primed seed can either be stored until the following planting season or remain viable in the soil during delayed germination.

Phosphorus (P) deficiency resulting from P fixation is a major constraint limiting sustainable rice cultivation in sub-Saharan Africa. Soil texture also affects P availability and use efficiency. In a factorial experiment, we evaluated the combined effect of soil texture (sand, clay loam, and clay) and P treatments P-dipping (Pdip) and two other broadcasted P fertilizer levels (Brod1 and Brod2) on the growth of NERICA 4 rice in the initial growth stages. Across all soil textures and P treatments, total plant biomass ranged from 1.06 to 4.63 g pot⁻¹. The Pdip treatment significantly increased shoot and root biomass relative to control from 1.27 to 1.98 and 0.23 to 0.38 g pot⁻¹, respectively. Mean photosynthetic rate values under Pdip (20.1 μmol m⁻² s⁻¹), Brod2 (19.5 μmol m⁻² s⁻¹), and Brod1 (19.3 μmol m⁻² s⁻¹) treatments showed significant 42%, 37%, and 36% increases over control, regardless of soil texture. In a striking contrast, P-dipping significantly promoted growth of root length under clay soil, but without a commensurate increase in shoot P uptake. Contrary to our hypothesis, the interactive effect of soil texture and P-dipping influenced NERICA 4 shoot and root physiological and morphological characteristics under clay loam soil texture as opposed to clay.

Phosphorus (P) deficiency is a major constraint limiting sustainable rice cultivation in sub-Saharan Africa—partly due to the deeply weathered soils that have low pH and contain high P-fixing Fe and Al oxides. Soil texture also affects P availability and use efficiency. In this study, we evaluated the combined effect of soil texture (sand, clay loam, and clay) and P treatments (P-dipping and two other P fertilizer levels) on growth of NERICA 4 rice in the initial growth stages. In a factorial experiment, we measured the interaction effects of soil texture and P treatments on shoot parameters and root morphology. Both treatments had significant interaction effects on all measured parameters, except shoot biomass, and affected the photosynthetic rate, with the highest mean values obtained under clay loam soil texture and P-dipping treatment, respectively. The treatments also affected rice root morphology. In a striking contrast, whereas mean root length under clay was significantly higher than that under clay loam texture, mean shoot P uptake under clay loam soil was significantly higher than that under clay soil texture. The interactive effect of soil texture and P-dipping influenced NERICA 4 shoot and root physiological and morphological characteristics under clay loam soil texture.