Foi realizado experimento visando estudar os efeitos da irrigação suplementar e da adubação nitrogenada na produtividade de aveia (Avena sativa L.), variedade UPF7, para ferragem. O delineamento experimental foi o de blocos ao acaso com parcelas subdivididas, com quatro repetições. Os tratamentos constaram da combinação de quatro lâminas de irrigação aplicadas quando a evaporação acumulada no tanque "Classe A" (ECA) atingia aproximadamente 30 mm (I = 0%, I = 50%, I = 100% e I = 150% de ECA) e quatro níveis de adubação nitrogenada (N = O, N = 80, N = 160 e N = 240 kg.ha-1 de nitrogênio). A máxima produtividade total de matéria seca (6,9 Lha-1) foi estimada para 319,2 mm de água e 152,4 kg.ha-1 de nitrogênio. Aos preços considerados para insumos e produto, a máxima receita líquida (R$ 897.ha-1) foi obtida para 310 mm de água e 120 kg.ha-1 de nitrogênio.

This study was conducted to determine the effects of supplemental irrigation and nitrogen fertilization on forage oat (Avena sativa, L.) productivity, variety UPF7. The experiment was a split-plot randomized block design with four replications. The experimental unit consisted of combinations of four irrigation depths applied when cumulative Classe A pan evaporation (ECA) approximately reached 30 mm, (I = 0%, I = 50%, I = 100% and I = 150% of ECA), and four nitrogen levels (N = O, N = 80, N = 160 e N = 240 kg.ha-1). The total maximum productivity of dry matter (6,9 t.ha-1) was obtained for the water depth of 319,2 mm and 152,4 kg.ha-1 of nitrogen. For the considered prices, the water and nitrogen levels that induced the maximum net income were 310 mm and 120 kg.ha-1, respectively, reaching a maximum net return of R$ 897.ha-1.

During the period 1980-1986, we captured triatomine bugs and mammalian reservoir hosts from sylvatic and domestic situations in different municipalities of the State of Minas Gerais. Trypanosoma cruzi was isolated from captured bugs, mammals and patients. After cultivation in LIT medium, the electrophoretic enzyme profiles were determined. We obtained atotal of 32 parasite isolates from regions with active domestic transmission, and 24 isolates form areas under control. For the first areas the results suggest introduction of T. cruzi from sylvatic habitats, through incursion of infected opossums and/or sylvatic T. sordida, which appears to have given rise to at least one acute human infection. Of particular interest is the finding of sylvatic opossums and a T. sordida nymph infected with ZB, that could indicate return of parasites from chronic human infections to sylvatic transmission cycles. For the areas under control we also interpret the results as interaction between sylvatic and domestic cycles of transmission, here through the invasion of houses by bugs carrying the Z1 zymodeme from the sylvatic environment. The Multivariate Correspondence Analysis gives a spatial description between the different parasite isolates and confirms the existence of a bridge in the opposite direction in the region with active vectorial transmission including the exporting of Z2 through the peridomestic environment into the sylvatic cycle. For the others areas this bridge corresponds especially to Panstrongylus megistus, importing Z1 into the domestic environment.