Mycotoxin occurrence in maize produced in Northern Italy over the years 2009-2011 and focus on the role of crop related factors

The occurrence of mycotoxins associated with Fusarium spp. and Aspergillus flavus in Northern Italy,\r\nand the role of cropping systems, were investigated on 140 field samples collected over the years 2009–2011. Samples\r\nwere analysed for fumonisins B1 and B2 (FBs), aflatoxins B1, B2, G1 and G2 (AFs), deoxynivalenol (DON) and\r\nzearalenone (ZEN) using validated analytical methods. Information on: maize hybrid, preceding crop, tillage applied,\r\nmineral nutrition, pest and disease control, severity of European Corn Borer (ECB) attack, sowing and harvesting\r\ndates, kernel moisture at harvesting and longitude of the sampled province, were also collected. During\r\nthis period there were distinct differences in FBs and AFs concentrations between years and geographic origins,\r\nand very low contamination with DON and ZEN was always found. The incidence of AFs exceeded 75% across\r\nall samples, and was almost 100% for FBs. The meteorological trends were quite different in the 3 years surveyed.\r\n2009 was the coldest in June and the warmest in August, 2010 the most humid, and in 2011 cold weather occurred\r\nduring flowering and dry conditions during ripening. The run of a logistic equation with the backward stepwise\r\napproach selected three parameters, (seeding week, ECB severity and longitude of sampling province) to predict\r\nAFB1 contamination and four parameters (year, sowing week, ECB severity and longitude of sampling province)\r\nto predict FB contamination. The internal validation gave good results, with 76% correct predictions. The probability\r\nof harvesting maize with more than 5 μg kg-1 of AFB1 varied between 86 and 5%, and the probability of\r\nharvesting maize with more than 4,000 μg kg-1 of FBs varied between 81 and 2%, respectively, for conducive and\r\nnon-conducive environments. Therefore, considerable variability was found even if a limited area and only 3 years\r\nwere considered.