TRADE AND MARKET I NG Does climate change also have an influence on variety development? Sjefke Allefs, Agrico Research: ‘The differences this year were already much greater than the climate model had predicted’ ‘I have my doubts about the massive scale on which the predictions about climate is generally accepted; it’s almost frightening. Especially because of the enormous consequences. I find the idea that man can turn the knobs of a hypothetical thermostat with which the climate can be regulated depressing. I think it rather naïve’, Sjef Allefs starts his lecture at the Agrico breeding station in the village of Bant. ‘This applies to both the role of global warming and that of CO2 increase. It already starts with the fact that a climate model is only a model. This means that it’s based on a large number of associated assumptions. The models were already 2 degrees Celsius too high in forecasting the temperature of the current seasons. That’s a first salient detail. I still remember the summer of 1976. It was the driest summer ever. That wasn’t considered a matter of climate change in those days. However, today that same thing would suddenly be due to climate change. There’s supposed to be a rise in tenths of degrees since measurements started in 1880, but how accurate were those measurements in the nineteenth century? The climate model of the Royal Netherlands Meteorological Institute (KNMI) is based on rising temperatures and their consequences, whereby the most sombre scenario predicts a temperature that is 2 degrees higher compared to 1990. I’ve looked up the month of July again in the random summers of 2010 and 2011. The month that potatoes are at peak growth growth in the Netherlands. In 2010, it was 3 degrees warmer than the annual average and in 2011 it was 2 degrees cooler. That’s a difference in temperature of 5 degrees! And yet we experienced these summers as quite normal production years. This means that potatoes are already able to counterbalance a temperature difference of 5 degrees without any problem. The differences in a year are therefore already much greater than the most sombre climate model forecasts. We select our varieties over a series of years in the continuously-changing seasons. What you can see is that potatoes are already rather flexible. For example, they can grow in varying day lengths, differing degrees of sunshine and average temperature conditions. Moreover, hot and cold weather can also change within a season. Take our Arizona variety, for example. We grow seed of that variety in the Netherlands, and the consumption potatoes are grown in sixty countries. The variety adjusts well in the varying growing conditions. In the Netherlands, the growing season starts cold, it gradually warms up, and then mostly cools down again. In the Mediterranean, the start of the season is also a bit colder, but after that it only gets hotter. We’re looking for varieties that produce good yields under all weather conditions, with the Spunta variety being the one we need to beat. This variety is neither extremely good nor extremely bad. It’s a reliable variety, that’s why it’s doing so well. We’re looking for varieties that are tolerant of the climate situation in which they’re grown. That’s the holy grail of potato breeding. If we understood how that works genetically, we’d first look at that. It’s somehow connected with genetics, but we don’t know exactly how, because the interaction between genes and growing conditions is extremely complicated. This is why we breeders need many years to test the seedlings under a great many climatic conditions. We’re now also working together with Utrecht University. In that research, we’ll examine whether potato genetics has the capacity to deal with extremely wet conditions. When a potato plant is under water for 24 hours, the tubers will start rotting. But there are plants related to the potato such as woody nightshade, which seems to be made to be permanently under water’, Allefs explains. Lammert Buwalda, Semagri: ‘What makes breeding In his office in Lelystad, Lammert Buwalda of Semagri immediately points to the Nubila variety from Harm Kannegieter, a breeder of non-protected varieties. He tells us that the Nubila is a typical example of how his business selects and introduces varieties. ‘The biggest market for this seed is around the Mediterranean Sea and the Middle East. An area where the most climate-resistant Spunta variety still influences the market. The Nubila is a crossing between the Fabula x Bellina, resulting in a sizeable, high-yielding variety and a strikingly attractive presentation. To find such varieties, we’ve opted for working with breeders of non-protected varieties. In our company, the breeders determine the path. To feed them with ideas, we regu26 Potato World 2017 • number 2 Pagina 25
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