Grapevine is cultivated in more than 77.500 ha in Brazil. Grapevine cultivation is an important agricultural activity in the southern, northeastern and southeastern regions of the country. However, the excessive use of fungicides for disease control in grapevine is still an obstacle to production of grapes with high quality. Fungicides are applied even without the actual damage quantification of fungal diseases in different grapevine cultivars in Brazil, such as cv. Niagara rosada (Vitis labrusca). Quantification of damages is one of the justifications of the thematic project "Grape diseases: epidemiology, damage assessment and control (Process FAPESP 2013/24003-9)". Downy mildew (Plasmopara viticola) is one of the pathogens of this thematic study. The downy mildew causes serious damage mainly to grapevine Vitis vinifera. However, as showed in initial results of the thematic project, Plasmopara viticola causes reduction in biomass and carbohydrate production in Vitis labrusca, cv. Niagara rosada (Nogueira Júnior, 2016). This pathogen also reduces photosynthesis of leaves even in asymptomatic regions near the lesion in cv. Niagara rosada. One of the objectives of this proposal is to determine monocycle at different temperatures and effects of downy mildew on photosynthesis in different cultivars of Vitis vinifera and V. labrusca. This phase will be held under the supervision of Dr. Andreas von Tiedemann, at the Institute of Plant Pathology and Plant Protection at the University Georg - August - Göttingen in Germany, with the supply of genetic material by the Institute for Grapevine Breeding Geilweilerhof - JKI - Germany. During the internship at the University of Göttingen, the effect of downy mildew on photosynthesis will be determined through the virtual lesion concept (Bastiaans 1991) and diffusive photochemical and biochemical limitations (Nogueira Júnior et al., 2017) imposed by P. viticola in different grapevine cultivars. Information on limitations imposed by the pathogen on host photosynthesis with data on photosynthesis reduction in regions adjacent to the lesions, is of interest for parameterizing simulation models of damage caused by pathogens in different Vitis spp.
News published in Agência FAPESP Newsletter about the scholarship: