Forecasting the impact of climate change on potato (Solanum tuberosum) productivity in Gujarat and relative adaptation strategies

A study was carried out in Gujarat to assess the impact of climate change on potato (Solanum tubersoum L.) productivity, using the WOFOST crop growth-simulation model. Three potato cultivars of different maturity, viz ‘Kufri Badshah’, ‘Kufri Jyoti’ and ‘Kufri Pukhraj’, were selected as test varieties. The study was done for baseline scenario (2000) and for future climate scenarios (2020 and 2055) using A1FI scenario of temperature (SRES A1FI pathway) and atmospheric CO₂ (based on the Bern-CC model for A1FI scenario). Potential production of potato cultivars was estimated for 20 different locations across Gujarat. Under the baseline scenario, the mean productivity of ‘Kufri Badshah’, ‘Kufri Jyoti’ and ‘Kufri Pukhraj’ was 40.0, 36.0 and 37.4 t/ha, respectively. The increase in temperature during 2020 and 2055, decreased the productivity ranging from 11.5 to 14.5% during 2020 and from 22.9 to 33.9% in 2055 climate scenarios. The corresponding increase in CO₂ concentration enhanced the productivity ranging from 4.9 to 5.3% and 20.8 to 22.9% during 2020 and 2055 scenarios respectively. Overall, the combined effect of CO₂ and temperature decreased the productivity of ‘Kufri Badshah’, ‘Kufri Jyoti’ and ‘Kufri Pukhraj’ by 6.7, 9.4 and 9.5%, respectively, during 2020 and by 19.9, 23.3 and 25.6% for respective varieties during 2055. It was also found that rescheduling the date of planting and selecting suitable varieties can completely offset the impact of climate change on potato productivity during 2020 while it can reduce the decrease in yield from 22.3 to 9.7% during 2055. However, development of potato cultivars with high bulking period proportionate to their total crop duration are required to meet the challenges posed by climate change on potato crop in future.