symptoms of esca on merlot leaf. the grapevine trunk diseases

affected agricultural agriculture bacteria cell cells chlorosis colorful conditions disease dying esca farm farming field fruit fungicide fungus gardening grape grapevine growing growth industry infection injuring injury insecticides killing leaf leaves merlot microscopic moravia nobody pathogen pathogens petri phloem phytoplasmas plantation quality red region south spots spread spring stripe structure summer symptoms tissue vine vineyard vineyards viruses viticulture winery yellow