Abstract. From a series of experimental studies with pigs (12-16 kg), either pulmonary edema or liver failure emerged as a distinct pathogenetic expression of fumonisin B 1 (FB 1 ) toxicosis. The primary determinant as to which pathogenetic consequence developed was the quantity (dose) of the mycotoxin fed or intubated per kilogram of body weight per day. Pigs intubated with a minimum of 16 mg FB 1 /kg/day developed severe interlobular edema with or without hydrothorax and variably severe pulmonary edema. Pigs intubated with < 16 mg FB 1 /kg/day or pigs fed diets containing 200 mg FB 1 /kg of feed developed marked icterus and hepatocellular necrosis. The spectrum of degrees of severity of pulmonary edema observed in the experimental pigs allowed rational speculation regarding evolution of the pathologic changes.In 1988, the chemical structures of the fumonisins, a group of related mycotoxins elaborated by certain strains of Fusarium moniliforme, were published.

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Aflatoxin contamination of maize (Zea mays L.) is a chronic problem in the Southeastern USA, but varies greatly from year to year in its severity. Our primary objective was to assess the effect of planting date on aflatoxin concentrations in grain from knife‐wound inoculated ears during a five‐year study at Tifton, GA. We also evaluated the relationship between aflatoxin concentrations in maize grain and several environmental variables, especially those involving temperature and moisture. Five plantings of Funk's G‐4507 were made in 1982, six in 1983 and 1984, and 10 in 1986 and 1987. Average planting dates varied from about 1 March to 1 August. Eight to 12 wound‐inoculated, 10‐ear samples were assayed per planting date. Aflatoxin concentrations were not significantly related to insect damage or the percentage of ears with visible Aspergillus flavus Link ex Fries, but concentrations were correlated with maximum and minimum daily temperature and net daily evaporation during 20‐ to 40‐d and 40‐ to 60‐d periods following full silk. Combined and average correlations for these relationships were highly significant. Regressions of aflatoxin concentrations on planting date revealed a significant linear decrease in concentration (200–300 ppb per 15‐d delay in planting) from early to late. Simple coefficients of determination of 0.75 or greater also suggest a significant relationship when measured over periods of more than 1 yr. Early plantings in Georgia are believed to be at higher risk because the critical grain filling period, beginning 20 d after silking, falls when the seasonal maximum and minimum temperatures are highest and when net evaporation is at its peak.

Fifty samples of peanuts and 45 samples of com, collected in Georgia during 1990, were examined for the co-occurrence of cyclopiazonic acid (CPA) and aflatoxins (AF). The corn was collected from fields in Georgia, before harvest, under the mycotoxin- monitoring program of the U.S. Department of Agriculture's Agricultural Research Service. The peanuts were designated for oil production or animal feed because of visible damage to the nutmeats. CPA was determined by reversed-phase liquid chromatography (RPLC) using a linear gradient. Solvent A was methanol-water (85 +15), and solvent B was 4 mM ZnS04 in methanol-water (85 +15). The gradient started at 0% B and reached 100% B at 10 min. AF were determined by RPLC with postcolumn iodination. Of the 45 corn samples analyzed, 51 % were contaminated with CPA (&lt;25-2800 ng/g, av. 467 ng/g), and 87% were contaminated with AF (1-2300 ng/g, av. 252 ng/g). Of the 50 peanut samples, 90% contained CPA (&lt;50- 2900 ng/g, av. 460 ng/g), and 100% contained AF (3- 22 000 ng/g, av. 1685 ng/g). The identity of CPA was confirmed in selected samples of corn and peanuts by mass spectrometry.

The experiment in this paper was developed in order to resolve the tension between the importance of HPLC versus the high lab cost to execute the experiment.