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Navarrete, I.

Publications and source records attributed to Navarrete, I..

2 recordsLinked to original sources

Management performance mapping: the value of information for regional prioritization of project interventions

Policymakers and donors often need to identify the locations and settings where technologies are most likely to have important effects, to increase the benefits from agricultural development or extension efforts. Higher quality information may help to target the high-payoff locations. The value of information (VOI) in this context is formalized by evaluating the results of decision making guided by a set of information compared to the results of acting without taking the information into account. We present a framework for management performance mapping that includes evaluating the VOI for decision making about geographic priorities in regional intervention strategies, in case studies of Andean and Kenyan potato seed systems. We illustrate use of Bayesian network models and recursive partitioning to characterize the relationship between seed health and yield responses and environmental and management predictors used in studies of seed degeneration. These analyses address the expected performance of an intervention based on geographic predictor variables. In the Andean example, positive selection of seed from asymptomatic plants was more effective at high altitudes in Ecuador. In the Kenyan example, there was the potential to target locations with higher technology adoption rates and with higher potato cropland connectivity, i.e., a likely more important role in regional epidemics. Targeting training to high performance areas would often provide more benefits than would random selection of target areas. We illustrate how assessing the VOI can help inform targeted development programs and support a culture of continuous improvement for interventions.

ecology

Health quality of seed potato and yield losses in Ecuador

Low potato productivity in Ecuador is partly attributed to the use of low quality seed tubers. However, seed health quality in Ecuador, and its interaction with altitude and yield has been poorly investigated. We surveyed 11 farmers fields in Ecuador in 2010 to determine incidence and severity of pathogens and pests affecting foliage and seed tubers, and to determine the influence of altitude and seed sources over seed health quality (pathogen and pest diversity in/on the seed tuber). Additionally, a field experiment was planted in CIP-Quito using assessed seed tubers collected from surveyed farmers fields, during 2010 and 2011, to determine yield responses to seed health quality. Results show that foliage was mainly affected by late blight and flea beetle damages while seed tubers were predominantly affected by black scurf, andean weevil damages, potato virus S and potato virus X. We found that seed health quality was similar among farmers seed sources, and detected that increase in altitude decreased seed-borne virus diversity. Only seed-borne pathogens and presence of mechanical damages were found to explain yield variation. Seed-borne pathogens affecting yield variation were black scurf on seed tubers, potato virus S, and potato yellow vein virus. However, these factors changed when regressions were performed per seed source or variety. The yield responses to seed health quality of each variety should be considered to fine-tune integrated pest management strategies.

ecology