Sustainable adaptation of fruit tree production to episodic drought

Recently, prolonged periods of drought have resulted in significant yield losses in fruit trees. Expected climate change scenarios are not encouraging either, indicating an increase in the frequency, duration and severity of droughts, thus threatening further the Danish fruit industry. This is a very big challenge for Danish fruit growers, as they lack reliable tools and knowledge to protect their trees from drought. Irrigation seems to be the obvious solution, but it is not sustainable, as competition for good quality water has increased among water users and many fruit growers do not have access to it or are limited in using it. This project will develop effective and sustainable tools and practices to mitigate the negative effects of drought on fruit tree production and thereby future-proof the Danish fruit industry. The project will identify drought-resistant apple varieties and rootstocks, and will test and optimize the use of environmentally friendly biological solutions that increase drought tolerance or reduce water loss from leaves via transpiration, thereby increasing production under drought stress. In addition, we will investigate the potential of promoting symbiosis of apple trees with arbuscular mycorrhizal fungi to prevent drought stress effects and increase drought tolerance. Finally, we will apply different types of compost to the soil to improve its properties and thus its ability to retain water.