Corn samples harvested in 1997, 1998 and 1999 from different soil types were stored at different conditions (temperature, moisture content, state of kernels) for six months. The Fusarium contamination was examined by plate dilution method and the amount of mycotoxins (F-2, T-2, HT-2, DON, DAS) were determined applying HPLC method immediately af...ter harvesting and in the third and sixth month of storage. The aim of our study was to find correlation between the ecological factors, storage conditions and the examined parameters mentioned above, as well as to prove them statistically. According to the examinations carried out after harvesting we could state that the soil type had no effect on the parameters. Analysing the effect of the years we found considerable differences. The Fusarium infection of corn samples in 1998, while the toxin contamination in 1999 was the highest. The results of storage experiment show that year (number of microscopic fungi, F-2, T-2, HT-2, DAS and total toxin content) and moisture content of kernels (F-2, T-2, and total toxin content) have a significant effect on the examined parameters. We could prove the effect of temperature on the T-2 content (samples with natural moisture content) and DON content (samples with 14% moisture content). Higher values were found at higher temperature storage. The ratio of damaged kernels influenced the DON concentration in the non- wetted samples and the number of microscopic fungi in the wetted samples.
In 1998 the Fusarium infection was studied visually and microbiologically and also F-2, T-2, HT-2, DAS and DON contamination were measured using 22 winter wheat samples. The correlation between the different parameters of 22 wheat samples were determined by regression analysis. According to our results we can state the following.
There is no
Our results indicate however – though it is not proven statistically – that those samples in which the Fusarium infection did not exceed the limit of the standard, also had low toxin contamination, therefore they can be used as components of forage.
It is a considerable problem, however, that according to the visual qualification, such samples are excluded from the later utilisation, wherein the toxin contamination does not justify such action. Therefore, it is necessary to examine the toxin content of those samples which show high infection by visual symptoms. To reducing the number of expensive toxin examinations it would be advisable to change the currently used 0,5% limit which is indicated in the standard for a higher value of infection, for example to 2%, as recommended by Mesterházy (1998).