Seaweed (Ascophyllum nodosum L.) extract improved the physiology, promoted the vegetative development and yield of grapevines under arid/semiarid condition

Many parts of the viticulture areas around the world are located under continental climate conditions typically characterized with hot and dry summer and cold winters that pressurizes the sustainability of grape production on the face of ever-increasing climate change events. Under such stressful conditions, vine physiology and development should be promoted by precision agricultural strategies such as the use of organic plant growth stimulators. A two-year experiment was performed to investigate the effects of foliar seaweed extract ( Ascophyllum nodosum L.) treatment on the physiology, growth and agronomy of the vines of ‘Alphonse Lavallée’ and ‘Prima’ cultivars under arid/semiarid soil under continental climate condition. Foliar seaweed pulverizations at 0.3% concentration, performed three times during hot and dry summer season, increased the leaf stomatal conductance, mitigated the excessive increase in leaf temperature and improved the leaf chlorophyll content of two cultivars for both years. Such improvements in vine physiology led to promotion in leaf and shoot development, leading to increase in vine yield. To sum up, foliar seaweed extract treatment would be recommended as practical solution for a precision viticulture under the stressful condition of continental climate.