Diseases and pests of sweet potato: south-east Asia, the Pacific and East Africa (NRI Bulletin No. 46)

The bulletin reviews available information on biotic factors affecting sweet potato in eight countries in three important tropical production regions - south-east Asia, the Pacific, and east Africa. Information was obtained both from published reports, and directly from visits to key root and tuber-crop research institutions and discussions with many researchers in the Philippines, Indonesia, Thailand, Papua New Guinea, Uganda, Rwanda and Kenya. The most important diseases and pests are identified; the current status of sweet-potato research is reviewed; and specific recommendations are made for future research in these countries

Driver Simulation-Based Training of Heavy Vehicle Operators: Targeted Task Analysis and Considerations for Training Design

The use of simulation for training operators of heavy vehicles is gaining momentum. However, there still exists a gap in knowledge about the appropriate skills to target, and in particular, with regards to skill areas of a nontechnical nature. By taking a first-principles approach, we first sought to conduct a targeted analysis of the heavy vehicle operator task and, in turn, to assess which of the goal-based tasks identified through the task analysis would be most appropriate for simulation-based training. In general, simulation provides a safe and efficient option for training critical skills that could otherwise be trained on road (e.g., gear shifting). Simulation also provides the opportunity to train critical skills in a structured and formal way that could otherwise not be achieved in a real heavy vehicle, except on an opportunistic or incidental basis (e.g., hazard perception). Nonetheless, the challenge for training system design still remains: what constitutes the appropriate balance between simulator-based and real truckbased practical training, and for which curriculum components and skill sets

Variability in decision-making and critical cue use by different road users at rail level crossings

Collisions at rail level crossings (RLXs) are typically high-severity and high-cost, often involving serious injuries, fatalities and major disruptions to the transport network. Most research examining behaviour at RLXs has focused exclusively on drivers and consequently there is little knowledge on how other road users make decisions at RLXs. We collected drivers’, motorcyclists’, bicyclists’ and pedestrians’ self-reported daily experiences at RLXs for two weeks, focusing on behaviour, decision-making and information use in the presence of a train and/or activated RLX signals. Both information use and behaviour differed between road users. Visual information (e.g., flashing lights) was more influential for motorists, whereas pedestrians and cyclists relied more on auditory information (e.g., bells). Pedestrians were also more likely to violate active RLX warnings and/or cross before an approaching train. These results emphasise the importance of adopting holistic RLX design approaches that support cognition and behaviour across for all road users.Practitioner summary: This study explores how information use and decision-making at rail level crossings (RLXs) differs between road user groups, using a two-week self-report study. Most users make safe decisions, but pedestrians are most likely to violate RLX warnings. Information use (visual vs. auditory) also differs substantially between road user groups

Random amplified polymorphic DNA variation within and among bean landrace mixtures (Phaseolus vulgaris L.) from Tanzania

Genetic characterization of 51 individual pure lines from 13 landraces of three common bean (Phaseolus vulgaris L.) mixtures from the southern highlands of Tanzania was undertaken using random amplified polymorphic DNA (RAPD) analysis. A dendrogram generated by cluster analysis from data derived from fragments amplified by 12 random 10-base primers divided the bean individuals onto two main branches with less than 60% genetic similarity. Branches A and B subdivided into two and four clusters, respectively. Mixture 2, comprising three landraces, was the most uniform, most plants appearing on cluster 4 of branch B. Three of the four landraces of mixture 1 appeared on cluster 3 of branch B while the fourth landrace appeared on major branch A. Mixture 3 showed the greatest genetic variation with components appearing on both major branches. The clear separation of the 13 landraces onto two main branches of the dendrogram together with phenotypic characters, notably variation in bean size, suggests that the two groups might represent two distinct gene pools of P. vulgari

Grain legume seed systems for smallholder farmers: Perspectives on successful innovations

Grain legumes are nutritionally important components of smallholder farming systems in sub-Saharan Africa and Asia. Unfortunately, limited access to quality seed of improved varieties at affordable prices due to inadequate seed systems has reduced their contribution to improving nutrition and reducing poverty in these regions. This paper analyses four seed systems case studies: chickpea in Ethiopia and Myanmar; cowpea in Nigeria; and tropical grain legumes in Nigeria, Tanzania and Uganda highlighting outcomes, lessons learned, and the enabling factors which supported the successful innovations. All four case studies highlighted at least some of the following outcomes: increased adoption of improved varieties and area planted; increased productivity and income to farmers; improved market access and growth; and significant national economic benefits. Important lessons were learned including the value of small seed packets to reach many farmers; the value of innovative partnerships; capacity building of value chain actors; and continuity and coherence of funding through Tropical Legumes projects II and III and the recently funded Accelerated Varietal Improvement and Seed Delivery of Legumes and Cereals in Africa (AVISA) project. Successful adoption of innovations depends not just on the right technologies but also on the enabling environment. The case studies clearly showed that market demand was correctly identified, establishment of successful partners and institutional linkages overcame constraints in production and delivery of improved seed to smallholders, and fostered conducive policies supported national seed systems. All were integral to seed system viability and sustainability. It is hoped that these examples will provide potential models for future grain legume seed systems efforts. In addition, the analysis identified a number of areas that require further research

Is Users’ Trust during Automated Driving Different When Using an Ambient Light HMI, Compared to an Auditory HMI?

The aim of this study was to compare the success of two different Human Machine Interfaces (HMIs) in attracting drivers’ attention when they were engaged in a Non-Driving-Related Task (NDRT) during SAE Level 3 driving. We also assessed the value of each on drivers’ perceived safety and trust. A driving simulator experiment was used to investigate drivers’ response to a non-safety-critical transition of control and five cut-in events (one hard; deceleration of 2.4 m/s2, and 4 subtle; deceleration of ~1.16 m/s2) over the course of the automated drive. The experiment used two types of HMI to trigger a takeover request (TOR): one Light-band display that flashed whenever the drivers needed to takeover control; and one auditory warning. Results showed that drivers’ levels of trust in automation were similar for both HMI conditions, in all scenarios, except during a hard cut-in event. Regarding the HMI’s capabilities to support a takeover process, the study found no differences in drivers’ takeover performance or overall gaze distribution. However, with the Light-band HMI, drivers were more likely to focus their attention to the road centre first after a takeover request. Although a high proportion of glances towards the dashboard of the vehicle was seen for both HMIs during the takeover process, the value of these ambient lighting signals for conveying automation status and takeover messages may be useful to help drivers direct their visual attention to the most suitable area after a takeover, such as the forward roadway