Marcelo Barreto da Silva

Sistemas de consórcio milho feijão para a região do Vale do Rio Doce, Minas Gerais

O experimento foi conduzido no campo experimental da Univale de dezembro/98 a maio/99. Foram avaliados tres sistemas consorciados de milho e feijao: fileiras duplas de milho espacadas de 0,5 m, com e 1,5 m entre as duplas, espaco ocupado com tres fileiras de feijao (sistema 1); fileiras simples de milho espacadas de 1,0 m com uma fileira intercalar de feijao (sistema 2) e fileiras simples de milho espacadas de 1,0 m com duas fileiras intercalares de feijao (sistema 3), alem dos plantios solteiros. O milho utilizado foi o hibrido AG1051 e o feijao, a cultivar Carioca CI257. As culturas foram semeadas simultaneamente e todos os sulcos adubados. Foram avaliados no feijao os componentes da producao e a produtividade; no milho, a producao de massa verde para silagem e a produtividade. No sistema consorciado, o numero de vagens por planta de feijao sofreu reducao significativa em relacao ao plantio solteiro, sendo o fator que mais contribuiu para queda da produtividade, enquanto os demais componentes, numero de sementes por vagem e peso de 100 sementes, nao diferiram do plantio solteiro. No milho, o plantio em fileiras duplas reduziu significativamente a sua produtividade. O sistema 3 apresentou maior indice de equivalencia de area quando se considerou a producao de graos e a producao de milho silagem.

Nematofauna associada à cultura do quiabo na região leste de Minas Gerais

Okra has a cultural and social importance for the State of Minas Gerais (MG), and 34,2% of the volume marketed in the Ceasa/Contagem, MG, come from the municipalities located near Caratinga and Governador Valadares. The okra production is influenced for the infection caused by the root-knot nematodes (Meloidogyne spp.). The main species of these nematodes attacking okra have already been reported in Brazil, and some of them can cause plant death. The correct identification of Meloidogyne species and, or races infecting okra roots is mandatory for choosing appropriate control measures. To determine the occurrence and distribution of Meloidogyne spp. and other nematodes in the area of the East of MG, 70 soil and root samples coming from 14 municipalities were appraised for morphological and isoenzymatic characteristics. Among the populations of Meloidogyne spp., M. incognita (Esterase phenotypes I1 and I2) prevailed and were followed by M. javanica (phenotypes J2 and J3) and M. arenaria (phenotypes A2). The species M. mayaguensis was confirmed by the phenotypes: esterase (M2), malate dehydrogenase (N3), superoxide dismutase (N2) and glutamate oxaloacetate transaminase (N3). This is the first report of the M. mayaguensis occurrence in MG. Other nematodes associated with the okra plants were Aphelenchus sp., Criconemella sp., Helicotylenchus spp., Pratylenchus brachyurus and P. coffeae, Rotylenchulus reniformis, Rotylenchus sp., Tylenchus sp. and Tylenchorhynchus sp.

Trichoderma spp. decrease Fusarium root rot in common bean

The effectiveness of six Trichoderma-based commercial products (TCP) in controlling Fusarium root rot (FRR) in common bean was assessed under field conditions. Three TCP, used for seed treatment or applied in the furrow, increased seedling emergence as much as the fungicide fludioxonil. FRR incidence was not affected, but all TCP and fludioxonil reduced the disease severity, compared to control. Application of Trichoderma-based products was as effective as that of fludioxonil in FRR management.