A simple and cost-effective diagnostic of Macrophomina phaseolina on watermelon by direct PCR oleh Suzana Marjorie Freire e Silva, Gilsivan Sales Medeiros de Aquino, Talison Eugenio da Costa, Anna Luisa de Carvalho Brito, Andréia Mitsa Paiva Negreiros, Rui Sales Júnior, Tatsuya Nagata, Ioná Araujo Santos Holanda