An adaptable crop may be put to the test
By Rosalie I. Tennison
Amid the doom and gloom about how global warming will change the way people live and the way food is produced, potatoes are seen as the one crop that is most adaptable to whatever changes occur.
By Rosalie I. Tennison
Amid the doom and gloom about how global warming will change the way people live and the way food is produced, potatoes are seen as the one crop that is most adaptable to whatever changes occur. This is good news for growers who may find themselves in a position to provide potatoes to a wider world market. “My feeling is that potatoes are very adaptable because they originally came from the mountainous areas of Peru and Bolivia, which makes them a very tough plant,” comments Dr. Alan McKeown, a researcher in the Department of Plant Agriculture at the University of Guelph. “Climate change will affect yields, so in hotter areas south of Canada, cool season crops, such as potato, will see yield decreases. Rainfall is also a factor, not just temperature change. So, heat and drought will cause a “double whammy,” which will cause potato production to be driven north and to higher elevations.”
|Potatoes are highly adaptable, yet still require 20 to 24 inches of rainfall during the course of a growing season. Photo by Ralph Pearce
Assuming, he adds, there is suitable soil and access to water through rainfall or irrigation in these areas. He points out that much of Canada is Canadian Shield and tundra, which “are not very conducive” to crop production.
An international expert on climate issues, McKeown suggests Russia and Canada could become the world’s leading producers of potatoes if or when climate change exhibits its full impact on the world’s premier agricultural areas. Dr. Jim Salinger of the University of Auckland, in New Zealand, concurs that potatoes could be one of the foods of the future, and he echoes the “growing them at higher latitudes and farther north” notion. “The northern climates in Canada and Russia are well suited for future potato production because the cooler temperatures, combined with the long days, provide a good environment for increasing yields,” Salinger explains. “As long as the optimum temperature is between 16 and 19 degrees C, with temperatures not falling below -2 degrees C in the growing season, then production will be possible in these climates as long as the water requirements of 500 to 600 millimetres (20 to 24 inches) during the growing season are fulfilled.”
McKeown says the nature of the potato plant is what makes it so adaptable. “The soil protects the storage organs and having them below ground protects against frost,” he explains. Emphasis will be placed on varieties that withstand erratic climatic conditions such as inconsistent temperatures and moisture issues. “We’ll have to look for varieties that do well under increasingly variable conditions.”In fact, heritage varieties might make a comeback or become the breeding stock for developing new “climate-tolerant” varieties. “
Heritage varieties have a wider tolerance of the range of environmental conditions, and also have a higher resistance to pests and diseases,” adds Salinger. “These could be made as a tradeoff with higher yields.”
McKeown sees heritage varieties as a good source of germplasm for desired characteristics, but does not believe they will be adequate for commercial production.
Although there are still some who do not believe that climate change is really occurring, McKeown says weather changes are happening, but it may be a long time before the full impact of them is known. He points out that variable weather is an issue now and always has been, and that will not likely change. It is possible the variability may become more extreme. “If extreme variability becomes the norm globally, we will have some problems,” he says.
Both McKeown and Salinger see agronomic research and variety development as key if northern climes are to become the potato producers for the entire planet. “Certainly, agronomic research will have to keep up,” comments McKeown. “The World Bank reports that agronomic research has been declining. If we don’t put resources into studying the agronomic changes that might occur due to climate change, it will be harder for growers to adapt. Research is the cornerstone of food security.
“Breeding programs will need to shift into those areas where potential new cultivars can be raised because of the shift in the photoperiod (the length of day/night),” adds Salinger.
New territory for various reasons
Of course, continues McKeown, the world is entering unknown territory with climate change while experiencing an increase in carbon dioxide. “All our plant physiology and field work is done in an area of about 330 to 340 ppm (parts per million) of carbon dioxide and we are now approaching 380 ppm. How will this change the applications we developed in the 1950s and 1960s? At what point will an increase in carbon dioxide change the applicability of our past research?”
Salinger suggests more modelling needs to be done in Canada and Russia to determine how climate change is affecting the way crops are developed and grown. Then, he says, the models need to be applied to potatoes.
Disease pressure may change as well, because, suggests Salinger, if the air becomes more humid, there will be more pathogens. But, if the air becomes dryer, there will be less disease pressure. The former scenario may require more emphasis to be placed on developing varieties with disease tolerance. “The weed spectrum may change as well,” adds McKeown. Certainly, if potatoes grow well at cooler, higher latitudes, then the weeds will likely also adapt and the products that are used for weed control now may no longer be effective. “Everything will likely change from weeds to diseases and maybe the nutritional needs of the crop will change.”
McKeown says these changes could lead to great opportunities for Canadian growers, and he suggests science could help them prepare by continuing classic agronomic work on crop developments and adaptability. “As humans, if we put the effort into solving the problem, we can,” he reasons.
While some see the future of the world in a dim light, potato producers could be facing a brighter outlook because they are experts at growing a crop that is adaptable and will most likely be a sought-after food source. The challenge will be based on agronomics and choosing varieties that will not be affected by temperature changes and increased levels of carbon dioxide. The concern is yields may decline. In the end, climate change could prove what growers have always known: the potato is a versatile crop that can help feed a changing world.