Effects of regulated deficit irrigation (RDI) on grape composition in Monastrell grapevines under semiarid conditions

Domesticated grapes are assumed to have originated in the Middle East. However, a considerable number of species are native in East Asian countries such as China, Korea and Japan as well. Evidence suggests that a total of seven species and eight varieties have been found to be native to Japan. A wide level variation in morphology, genetic and fruit composition exist in wild grape native to Japan.

Pendant une période de trois années le comportement productif et qualitatif de trois cépages tous indigènes de la région de Campania (Italie méridionale) dans deux terroirs de l’île d’Ischia a été étudié; ceci pour obtenir quelques indications préliminaires sur le comportement productif et qualitatif des cépages et sur la qualité des vins.

A multidisciplinary approach aiming at studying the grape-growing areas also referred as “Terroir” was initiated a few years ago in Switzerland.

Vine downy mildew is one of the most frequent diseases in intensive vineyards. Bordeaux mixture (B.m.), in order to control the disease has been applied onto vineyards since the end of the 19th century. The intensive use of Cu-fungicides could influence the physiology of grapevine. It is also possible that high amounts of foliar Cu sprays trigger stress responses in vine leaves.

Mediterranean viticulture is increasingly exposed to more frequent extreme conditions such as heat waves. These extreme events co-occur with low soil water content, high air vapor pressure deficit and high solar radiant energy fluxes and result in leaf and berry sunburn, lower yield, and berry quality, which is a major constraint for the sustainability of the sector. Grape growers must find ways to proper and effectively manage heat waves and extreme canopy and berry temperatures. Irrigation to keep soil moisture levels and enable adequate plant turgor, and convective and evaporative cooling emerged as a key tool to overcome this major challenge. The effects of irrigation on soil and plant water status are easily quantifiable but the impact of irrigation on soil and canopy temperature and on heat convection from soil to cluster zone remain less characterized. Therefore, a more detailed quantification of vineyard heat fluxes is highly relevant to better understand and implement strategies to limit the effects of extreme weather events on grapevine leaf and berry physiology and vineyards performance. Low-cost sensor technologies emerge as an opportunity to improve monitoring and support decision making in viticulture. However, validation of low-cost sensors is mandatory for practical applicability. A two-year study was carried in a vineyard in Alentejo, south of Portugal, using low-cost thermal cameras (FLIR One, 80×60 pixels and FLIR C5, 160×120 pixels, 8-14 µm, FLIR systems, USA) and pocket thermohygrometers (Extech RHT30, EXTECH instruments, USA) to monitor grapevine and soil temperatures. Preliminary results show that low-cost cameras can detect severe water stress and support the evaluation of vertical canopy temperature variability, providing information on soil surface temperature. All these thermal parameters can be relevant for soil and crop management and be used in decision support systems.