Penetration of 1,2-dibromo-3-chloropropane in a Florida soil.
Gas-liquid chromatography was used to detect movement of the nematicide, 1,2-dibromo-3-chloropropane (DBCP), in soil columns containing top- and subsoil of Astatula fine sand. Topsoil contained 1.4-1.6% organic matter and subsoil 0.20-0.25%. DBCP was applied at various rates as aqueous drenches. Depth of penetration was controlled by organic matter in topsoil and varied with the amount of water applied. Maximum DBCP penetration after 14 days was 28 cm; maximum water infiltration, 115 cm. Maximum depth of penetration was obtained with a water emulsion of 30 mug/ml of DBCP applied in 15 cm of water. DBCP applied in 5 cm of water to soils containing 2.0% and 0.125% organic matter penetrated 6 cm and 60 cm, respectively.
Control of citrus nematode Tylenchulus semipenetrans on fine-textured soil with DBCP and oxamyl.
Three grapefruit orchards on sour orange rootstock were treated by metering DBCP (l,2-dibromo-3-chloropropane) at 56 kg(a.i.)/ha into 15 cm of water in a flood irrigation system. In orchards with 43-49% clay in the surface foot, DBCP reduced numbers of Tylenchulus semipenetrans below control levels for 1.5-2.0 years. In the 3 orchards, DBCP treatment resulted in increases in yield or fruit size in the 2 seasons following treatment. No increases in yield, fruit size, or fruit numbers were observed the third season after treatment, but retreatment of a portion of one orchard after 2 years resulted in large increases in yield and fruit numbers the following harvest. Application of oxamyl twice annually as a foliar spray at 2.8 kg(a.i.)/ha reduced nematode populations to about 50% of control levels and resuhed in a large increase in yield in 1 of the 2 seasons tested. DBCP treatment of fine-textured soils controlled citrus nematode and increased yields, but its effect was not as long lasting as on coarser soil in other citrus areas. Foliar applications of oxamyl reduced nematode populations but were not as consistently effective as DBCP treatments.
As práticas profissionais no campo público de atenção à saúde bucal: o caso de dois municípios da Bahia
This paper examines the working facilities and processes of dentists in the primary healthcare systems of two towns in Bahia State, Brazil, striving to analyze the extent to which factors related to dental care, training, placement and professional profiles influence their practices. Semi-structured interviews were conducted with nine dentists in both towns, with work process organization patterns in Municipality C being closer to the structuring principles of Brazil's National Health System than in Municipality E. This seems to be related to management characteristics, with networking links among individual, collective, and preventive clinical activities and planning noted in Municipality C. Despite these differences, the practitioners presented similarities in terms of dual militancy and perceptions of the public and private healthcare fields. The hegemony of the private sector seems to be influencing the professional practices of dentists in the public health system.