Arable crops: Climate change leads to fungal infections

Mushrooms grow well when it is moist and warm – even on arable plants. This is likely to become a problem under future climate conditions. This means that they can adapt more quickly to antifungal agents.

Remco Stamm explains that if the climate becomes increasingly wetter and warmer in the future, more fungi will attack crops. He is a plant pathologist at the Christian Albrechts University in Kiel and works on diseases of cultivated plants. Because mushrooms grow especially well when they are moist and warm. “In that sense, I can now predict without looking at the model: if there are frequent showers and it gets a little warmer, that will definitely have an impact on fungal infection,” says Stamm.

You can already see what that means. For example, Stam and colleagues conducted experiments with the barley pathogen that causes Ramularia leaf spot.

“In fact, we've only seen this pathogen as a problem since the 1980s. Before that, it was always found in or on the plant, but no one ever suspected that the spots could become serious at some point,” Stamm says. Crop losses now range between 20 and 30 percent, especially in southern Germany, if the disease remains untreated.

Food Safety He threatened

In extreme cases, entire foods can be lost in the future because they are infected with fungi, explains Brijesh Singh. He is an environmental microbiologist at the University of Western Sydney. One example is the banana disease called Panama disease. Singh says it is so deadly that it will wipe out bananas in the areas where it occurs unless a solution is found in the near future.

“This is an extreme example. But many fungi have very strong impacts, leading to productivity losses of 20, 30 or 40 percent depending on the severity of the disease. So you can get an idea of ​​the impact on global food protection.”

Fungicides lead to resistance

Wheat, rice, potatoes and soybeans are also attacked by the fungus, and farmers suffer huge losses. As climate change progresses, the problem will get worse. Until now, chemical agents, i.e. fungicides, have been used against fungi. Biologist Singh says this is already partly a problem. Microbes can reproduce very quickly and therefore evolve more quickly. They can therefore develop resistance to chemicals very quickly.

More resistance to come

If the weather is warmer and more humid, fungi can adapt to chemicals more quickly and develop resistance even earlier. Scientist Stam says that agriculture will not be able to function fully without chemicals in the future.

However, other methods should also be used. “We have to test our plants under more extreme conditions,” Stamm says. “Drier and wetter.” If resistance to the fungus is found in wild species, it can be introduced into our cultivated plants using green genetic engineering.

Microbes as protection

Biologist Singh has another suggestion on how to deal with harmful fungi in the future. As with humans, some microorganisms, such as bacteria, viruses, or other fungi, can protect plants from disease-causing germs. “We know that plants have the ability to attract beneficial microbes that can protect them,” says Singh. “So, you have to target those beneficial microbes and apply them to the plant in a structured way so you can protect it.”

Alternatively, substances can be applied to arable plants that attract beneficial microbes. The advantage is that these microorganisms can also quickly adapt to changes. In this way, the race for healthy crops in the face of climate change can still be won.