Potatoes grown in Punjab safe from climate change

Can climate change trigger any benefits? Popular perception suggests a negative answer. But rise in atmospheric carbon dioxide concentration is actually good for agriculture as it helps in crop growth. In potato, for instance, every 100 parts per million increase in atmospheric carbon dioxide level results in 10 per cent yield increase besides substantial water saving.

The rise in temperature, of course, has a counter-balancing effect. Taking both factors into account, researchers at the Central Potato Research Institute, Shimla, have shown that climate change would marginally increase potato productivity in Punjab by 2020 and would have virtually no effect by 2050.

Potato being an important Indian food crop, the CPRI team was studying the impact of climate change on its productivity over a short and long time period with computer models because climate change is believed to have a profound effect on potato production in India. The growth of potato in India has been phenomenal since 1950 with capita availability rising from 4.37 to 21.52 kg in 2012.

For the impact assessment in Punjab, three potato cultivators namely Kufri Badshah, Kufri Jyoti and Kufri Pukhraj were picked up as they account for close to 90 per cent of potato acreage in Punjab.

The planting date was set on October 15 and simulations were run using weather data from the Indian Meteorological Department, between 1971 and 2000 for Punjab, which accounts for 4.48 per cent of India's total potato produce.

Out of the 22 districts, most of the cultivation is concentrated in 11 districts. Although their share to the total geographical area of Punjab is 44.4 per cent, their contribution to the total potato acreage of the state is 81.1 per cent.

Lying in the central and northern parts of Punjab, these are the districts which will be benefited the most by the combined effect of the likely increase in temperature and carbon dioxide concentration in 2020 as well as in 2055.

In these districts, the model has predicted a mean increase of 4.6, 4.7 and 5.4 per cent in the productivity for Kufri Badshah, Kufri Jyoti and Kufri Pukhraj respectively in 2020. However, the corresponding extent of increase is expected to be 1.8; 1.3 and 0.2 per cent respectively in 2055.

The figures are positive but lower than those of 2020. The remaining 13 districts, which constitute about 55.6 per cent to the state’s geographical area and contribute only 18.9 per cent to its share of potato acreage, are likely to see a decline in productivity of all the three varieties in 2020 as well as in 2055.

The weighted mean taken over these areas, after accounting for their proportionate share in Punjab’s current potato acreage, has shown that if the acreage scenario remains the same in the future, the overall productivity of Badshah, Jyoti and Pukhraj will increase by 3.3, 3.1 and 3.6 per cent respectively in 2020.

However, this benefit in productivity will be reversed with almost no change in Badshah’s and very little decline in the productivity of Jyoti and Pukhraj. The findings were reported in a recent issue of the journal Current Science.

“While north Punjab benefited, adverse effects were seen in southern Punjab. There are large variations within the state, whereas for the state as a whole, climate change does not have much of an impact,” said CPRI scientist V K Dua, who led the team.