Potato, sweet potato, and yam models for climate change: A review

Many crop models have been developed for potato, and a few for sweet potato, and yam. More than 30 potato models, two sweet potato models, and three yam models are described in the literature, and each differ in model structure. Some potato models have been applied to studies of nitrogen fertilizer, irrigation management, and climate change impact, but most of these models have never been validated with field measurements. The nitrogen dynamics of potato models CROPSYSTVB-CSPOTATO, EXpert-N-SPASS, and LINTUL-NPOTATO have been tested with some field data. LPOTCO and AQUACROP are two potato models that have been tested under elevated atmospheric CO2 conditions. None of the models have ever been tested with high temperature or heat stress data. The most tested and applied potato models include versions of LINTUL and SUBSTOR-Potato. Two sweet potato models, MADHURAM and SPOTCOMS, and two yam models, CROPSYSTVB-Yam and EPIC-Yam had limited field-testing under current climate conditions; however, these sweet potato and yam models are not ready for climate change impact assessments. To prepare potato, sweet potato, and yam models for climate change impact assessments, they need to be (i) calibrated with modern cultivars across agro-climatic zones; (ii) tested and improved with crop physiology and dynamic measurements of phenology, growth, partitioning, and water and nitrogen uptake under different crop management and environments; and (iii) tested and improved with field studies of crop responses to climate factors, including elevated CO2, water stress, increased temperature, heat stress, and combinations of these. Such extensive model testing and improvement with field experiments require a coordinated international effort and long-term commitment to potato, sweet potato, and yam research. (C) 2014 Elsevier B.V. All rights reserved.