Occurrence of Fusarium moniliforme and fumonisins in kernels of maize hybrids in Venezuela

Abstract

Fusarium moniliforme (FM) incidence and fumonisins (FUM) content were determined in white kernel samples of maize hybrids, harvested in farms of Guarico and Portuguesa states, Venezuela. FM incidence was estimated in subsamples placed on a malt-salt-agar medium. Values in the range of 0-15 % were considered low, from 15-30% intermediate, and more than 30% high. FUM content was quantified through specific immunoassay (Fumonitest, VICAM Sci. Tech., USA) and values above 1 ppm were considered high. The hybrids were compared using a completely randomized design and results were subjected to analysis of variance and mean comparisons. The correlation between FUM content and FM incidence was also estimated. FM and FUM were detected in all of the 89 samples. Mean incidence of FM among hybrids ranged from 26.0 to 72.0% in Portuguesa state (PS) and from 28.7 to 55.7 in Guarico state (GS). Significant differences among hybrids were determined in farms of El Playon and Turen, PS, and El Sombrero and El Socorro, GS. The incidence of FM was high in all hybrids. FUM contents ranged from 0.80 to 10.00 ppm in PS, and from 1.50 to 13.00 ppm in GS. Significant differences among hybrids were found in El Playon, PS, and in both locations of GS. Only in Ospino, PS, the content of FUM was correlated with FM incidence. This indicates the natural occurence of FM strains with different toxigenic capabilities. The results show that Guarico and Portuguesa states are hazardous regions regarding FM and FUM in maize kernels.