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The frequency and incidence of A. flavus and A. niger on barley, maize, soybean, sunflowerand wheat grain, the abundance of European corn borer (Ostrinia nubilalis) mothsand their interaction depending on weather conditions in the 2008-2012 period were studied.Under the agroecological conditions of Serbia, the species A. niger is more frequentthan A. flavus, and concerning the crop species, its frequency is highest in kernels of sunflower,than soybean, maize, barley and wheat. A. flavus was extremely dominant on allplant species in 2012 regarding its frequency: 100% on soybean, 95.3% on maize, 65.2% onbarley, 57.1% on sunflower and 45.8% on wheat. Furthermore, the incidence of A. flavus washigher in 2012 than in previous years. The uncommonly high frequency and incidence of A.flavus infestation of maize grain in 2012 were caused by extremely stressful agrometeorologicalconditions, high temperatures and drought over the period from flowering to waxymaturity of maize. The precipitation factor (Pf = precipitation sum / average monthly temperature)showed that 2012 was extremely arid in June (Pf = 0.57), July (Pf = 1.45), August (Pf= 0.15) and September (Pf = 1.42). European corn borer (ECB) was a second factor causingintensive occurrence of A. flavus on maize grain in 2012. The maximum flight of ECB mothswas recorded as early as in July (5,149) and, as a result of this, high damage and numerousinjuries were detected at harvest. Those injuries were covered by visible olive-green powderycolonies typical of A. flavus. In the chronology of A. flavus occurrence, these are thefirst data on its very high frequency and incidence under the agroecological conditions ofSerbia. As intensive infections with A. flavus were rare in the past 50 years, the level of aflatoxinsin maize grain was low. |
