Learn More
An artificial soil test was used to determine the LC50 values of carbaryl, chlorpyrifos, imidacloprid, cyfluthrin and fipronil against earthworms of the Pheretima group. For a 24-h interval, carbaryl was the most toxic to earthworms (LC50 = 77 mg kg-1), followed by imidacloprid (155 mg kg-1), cyfluthrin (351 mg kg-1), chlorpyrifos (390 mg kg-1) and fipronil(More)
Fumonisins are secondary, carcinogenic metabolites produced primarily by Fusarium verticillioides and Fusarium proliferatum on maize worldwide. The natural occurrence of fumonisin-producing Fusarium spp. and fumonisin contamination of maize grain were quantified in selected maize cultivars from principal production areas of South Africa. Grain colonization(More)
The effect of Bt-cotton, i.e. genetically modified cotton that contain genes expressing delta-endotoxin, on aphid, whitefly, chrysopid and coccinellid populations was determined with a two-year field study at a cotton farm near Marble Hall, South Africa. Although Bt-cotton is lepidopteran specific, non-lepidopteran arthropod populations may be indirectly(More)
Maize is most often infected by the fumonisin-producing Fusarium verticillioides. Total fumonisins of natural infected grain is made up of FB1, FB2 and FB3 with FB1 occurring naturally at higher levels. A maize plant can be infected with more than one F. verticillioides isolate, and finding a reliable method to elucidate the toxigenic potential of these(More)
The effects of the chitin synthesis inhibitor lufenuron against potato tuber moth, Phthorimaea operculella (Zeller), eggs were determined by topically exposing different age groups of eggs (1-4 d old) to treated potato tubers (Solanum tuberosum L.) under laboratory conditions. Larval hatch from both treated (4 and 12 g [AI]/100 liter) and untreated tubers(More)
OBJECTIVE To measure IgG antibody subclasses in previously healthy adult patients with acute community-acquired pneumonia, and to assess any association between differences of subtype levels and severity of illness or prognosis. DESIGN Prospective study. SETTING The intensive care unit (ICU) and general medical wards of Hillbrow Hospital, Johannesburg,(More)
  • 1