[1] Escuela Super Politecn Chimborazo, Fac Recursos Nat, Riobamba, Ecuador
[2] Univ Nacl Asuncion, Dept Protecc Vegetal, San Lorenzo, Central, Paraguay
[3] Agrosistemas, Riobamba, Ecuador
[4] Univ Fed Amazonas, Programa Posgrad Agron Trop, Manaus, Amazonas, Brazil
[5] Univ Fed Vicosa, Dept Fitopatol, BR-36570900 Vicosa, MG, Brazil