02266naa a2200193 a 450000100080000000500110000800800410001910000200006024501060008026000090018652016060019565301230180170000190192470000170194370000160196070000170197670000180199377300610201111317452022-02-14       2022    bl uuuu     u00u1 u    #d1 aFERREIRA, G. M.  aAlternative control of downy mildew and grapevine leaf spot on Vitis labrusca.h[electronic resource]  c2022  aThe number of organic vineyards around the metropolitan region of Curitiba-Paraná-Brazil is increasing, and alternative products to control downy mildew (Plasmopara viticola) and grapevine leaf spot (Pseudocercospora vitis) are crucial for the development of organic grape production. The objective of this study was to compare the efficacy of ten alternative products to control downy mildew on ?Concord? and grapevine leaf spot on ?Bordo?. The incidence and severity of both diseases were assessed to compare the treatments during two consecutive seasons in an organic vineyard under favorable weather conditions for the development of the diseases, in the metropolitan region of Curitiba, Paraná, Brazil. Biostimulant (Eurofit Max) reduced downy mildew incidence and severity in both seasons compared to the control. Lime sulfur reduced downy mildew severity only in the second season. Lime sulfur was the most effective treatment against grapevine leaf spot reducing the disease incidence and severity in both seasons. The severity of grapevine leaf spot was also reduced in the second season by Bacillus alcalophylus, biostimulant and chitosan. Lime sulfur showed phytotoxic effects at the doses and application frequency tested, reducing internode length and diameter on ?Bordo?. Biostimulant provided increased internode size in ?Concord?. This study demonstrated that alternative control may be effective against downy mildew and grapevine leaf spot. These findings contribute to the establishment of more sustainable V. labrusca production while maintaining the efficacy of disease control.  aPlasmopara viticola · Pseudocercospora vitis · Bacillus · Chitosan · Lime sulfur · Biostimulant · Essential oils1 aMOREIRA, R. R.1 aJAREK, T. M.1 aNESI, C. N.1 aBIASI, L. A.1 aMIO, L. L. M.  tAustralasian Plant Pathology, Switzerland, p. 1-8, 2022.