Rain, rain and more rain. St Peter is overdoing it this summer. The lousy weather is now getting on many people's nerves. The wet weather is particularly hard on farmers – or rather their potatoes. In wet conditions and temperatures between 15 and 25 degrees, the pathogens that cause late blight spread. The fungus thrives in warm and humid weather. The result: brownish leaves and rotten potatoes. «I have never experienced such a severe infestation», says farmer Simon Hauert from Niederösch BE to the «BauernZeitung».

80% of farmers affected by infestation

This is a nightmare for farmers – and the longer it goes on, the more the situation can threaten their livelihoods. In an interview with «watson», the President of the Swiss Potato Producers Association, Ruedi Fischer, speaks plainly: «Plant one potato, harvest one. A minus business.» Actually, eight to twelve potatoes should be harvested per potato planted.

This is already the third bad year in a row for the farmers. Extreme weather had already made life difficult for potato farmers in 2022 and 2023. 2024 is therefore a fateful year for some. Many have told him that they want to give the potatoes one last chance this year. A survey in «Schweizer Bauer» illustrates the precarious situation. According to the survey, almost 62% of the farmers questioned stated that they had suffered losses due to late blight and almost 18% even spoke of a total loss. Only 20% stated that the potatoes were not affected.

300 ha of potato fields already abandoned

Although this development is worrying, it is hardly surprising. For whom would a poor harvest three years in a row not threaten their livelihood? According to Fischer, this is why more and more farmers are abandoning potato production. Figures from a recent report in the «BauernZeitung» underpin this: more than 300 hectares of potato fields have already been abandoned. Due to the «disastrous» situation, experts are even advising this step.

But it's not just the potatoes that have been badly affected by the rainfall, but also the fruit. Burst cherries and fungal diseases were the order of the day this spring and summer. Because fungal treatments are only possible on fine days, plant protection also has its limits. According to the «BauernZeitung», a catastrophe is looming for the barley harvest. Both yields and quality were far below average. «Compared to previous years, 40% of barley is missing», Stefan Schär, Landi Marthalen ZH, is quoted as saying.

Fungal toxins threaten human and animal health

The heavy rainfall has also affected grain producers. For example, the rainfall during the wheat blossom caused an infestation of Fusarium, a species of mould fungi that is widespread worldwide. They cause rot, lead to crop losses and contamination of the harvested crop with toxins, so-called mycotoxins, which jeopardise human and animal health even in small quantities. Fusarium toxins can cause severe poisoning (toxicosis) in humans and animals via infested food and animal feed. They pose a threat to food safety. They are normally combated with fungicides, plant protection products that are effective against fungal infestation. If this is not possible, consumption poses a risk.

Not only the rain, but also the heat is causing problems for certain crops. For example, the heat is currently fuelling the Cercospora infestation, as «SchweizerBauer» writes in its current issue. Cercospora leaf spot is the most important and most damaging leaf disease on sugar beet, beetroot (beetroot) and chard (cabbage stalk). Early infestation significantly impairs beet yield and sugar content. Losses can be up to 40 %.

«It is important that new crop protection products are authorised»

The examples illustrate this: Solutions are needed. Niklaus Ramseyer, Managing Director of the Association of Swiss Potato Producers, told the «Aargauer Zeitung»: «Without crop protection, we would have suffered a total failure in many fields.» He added: «In the case of organic potatoes, where only copper can be used against late blight, the losses are very high.»

As extreme weather conditions such as heavy rainfall or heatwaves will occur more frequently in the future, modern crop protection products will also be needed in the future. As in human medicine, the most effective methods are needed to combat plant diseases. Farmer Simon Hauert also shares this opinion: «It is important that new plant protection products are constantly being authorised».

Resistant varieties will also be of great importance in the future. In particular, the aim is to make known varieties more resistant. This is also the conclusion of a study by Swisspatat. It shows that robust potato varieties can reduce the use of fungicides by 50-75% without increasing the risk of late blight. New breeding technologies such as Crispr offer an opportunity to make popular varieties more resistant.

15,000 tonnes of potatoes have to be imported

French winegrowers are also hoping for this. In order to equip traditional grape varieties with resistance to mildew and drought, they are calling for the authorisation of genome editing. In this way, they can continue to produce popular wine varieties that consumers actually demand.

One thing is clear: the situation of potato farmers is precarious. They urgently need solutions. The whole range of existing technologies must be utilised – be it the approval of new plant protection products or modern breeding technologies. Otherwise even more foreign potatoes will end up on our plates in future. As «SchweizerBauer» recently reported, an additional 15,000 tonnes of potatoes will soon be imported every year. Self-sufficiency and security of supply will suffer as a result.