Heat not rainfall the nemesis for future crops?

Crop scientists in the USA have begun to question whether heat and not rainfall, could be the main factor in changing crop yields over the coming century. It has long been assumed that the problems of drought, flooding and rising sea levels would all play a more important role in reducing future crop yields than heat, but Ken Boote of the University of Florida and others have begun to question this.

Boote says, "We don't grow tomatoes in the deep South in the summer. Pollination fails,". It seems that as temperatures rise, we will have difficulty maintaining the current crop yields.

"The magnitude of recent temperature trends is larger than those for precipitation in most situations," says David Lobell of Stanford University in an interview with Reuters. "We took a pretty conservative approach and still found sizable impacts. They certainly are happening already and not just something that will or might happen in the future,"

High night time temperatures are also seen as a key factor which reduce the lifetime of the plant and therefore reduce yield. Unfortunately, most research has so far focussed on drought resistant crops, rather than heat tolerance. This may have to change in the future, although it is claimed that heat tolerance is far harder to prescribe for.