Impact of climate change on potato productivity in Punjab – a simulation study

Impact assessment of climate change on potato productivity in Punjab for three potato cultivars of late (Kufri Badshah), medium (Kufri Jyoti) and early (Kufri Pukhraj) maturity groups was carried out for A1FI scenario of temperature and atmospheric CO2 of the years 2020 and 2055. The simulation study was done using WOFOST crop growth model for potential production at 13 locations in Punjab. The results from the simulation study were interpolated using kriging technique to generate maps of potential productivity and the changes thereon. It was estimated that rise in temperature alone will result in change in productivity of Kufri Badshah from +11.6% (Amritsar) to –10% (Fatehgarh) in 2020, whereas the change in productivity of Kufri Jyoti will be from +11.6% (Amritsar) to –11.6% (Fatehgarh) and of Kufri Pukhraj from +12% (Amritsar) to –11.5% (Mansa). During this period, CO2 fertilization is expected to increase tuber productivity from +3.9% to +4.5%, depending upon cultivar and location. However, in 2055, a mean decrease of 17.9 (Kufri Badshah), 21.1 (Kufri Jyoti) and 22% (Kufri Pukhraj) is likely in the productivity due to rise in temperature only, while the expected rise in CO2 is likely to bring about 17.3 (Kufri Badshah) to 18.5% (Kufri Jyoti) increase in potato productivity. It is estimated that under the combined influence of change in temperature and CO2, the productivity of potato cultivars will not be affected in 2020 over the baseline scenario, but will decline in 2055 (Kufri Badshah, –2.62%; Kufri Jyoti, –4.6% and Kufri Pukhraj, –5.3%), when the total geographical area of Punjab is considered. It is further shown that if the present distribution of potato acreage within Punjab remains unaltered in future, there will be benefits from climate change as the potential productivity of Kufri Badshah, Kufri Jyoti and Kufri Pukhraj will increase by 3.3%, 3.1% and 3.6% in 2020, although the potential productivity will again decline to baseline values in 2055 (+0.1%, –1.5% and –1.9% respectively).