The genera Aspergillus comprises species that produce mycotoxins such as aflatoxins, ochratoxins and patulin. These are cosmopolitan species, natural contaminants of agricultural products. In coffee grains, the most important Aspergillus species in terms of the risk of presenting mycotoxins belong to the genera Aspergillus Section Circumdati and Section Nigri. The purpose of this study was to assess the occurrence of isolated ochratoxigenic fungi of coffee grains from organic and conventional cultivation from the South of Minas Gerais, Brazil, as well as to evaluate which farming system presents higher contamination risk by ochratoxin A (OTA) produced by fungi. Thirty samples of coffee grains (Coffea arabica L.) were analysed, being 20 of them of conventional coffee grains and 10 of them organic. The microbiological analysis was done with the Direct Plating Technique in a Dichloran Rose Bengal Chloramphenicol Agar (DRBC) media. The identification was done based on the macro and micro morphological characteristics and on the toxigenic potential with the Plug Agar technique. From the 30 samples analysed, 480 filamentous fungi of the genera Aspergillus of the Circumdati and Nigri Sections were isolated. The ochratoxigenic species identified were: Aspergillus auricoumus, A. ochraceus, A. ostianus, A. niger and A. niger Aggregate. The most frequent species which produces ochratoxin A among the isolated ones was A. ochraceus, corresponding to 89.55%. There was no significant difference regarding the presence of ochratoxigenic A. ochreceus between the conventional and organic cultivation systems, which suggests that the contamination risk is similar for both cultivation systems.

Com o presente trabalho objetivou-se determinar o melhor processo de formação de mudas em diferentes níveis de sombreamento. O experimento foi conduzido no Setor de Cafeicultura do Departamento de Agricultura da ufla, onde mudas de cafeeiro (Coffea arabica L.)foram formadas sob quatro diferentes tipos de luminosidade, sendo: em pleno sol e sob sombrites, com 30%, 50% e 90% de sombreamento. Os tratamentos foram dispostos em um delineamento com blocos casualisados, sendo quatro o número de blocos. O experimento foi conduzido até que as mudas atingissem o terceiro-quarto pares de folhas. As avaliações constituíram as seguintes análises de crescimento: altura, diâmetro de caule, número de pares de folha, peso seco de raíz, peso seco de parte aérea e área foliar. Concluiu-se que para as características de crescimento analisadas, as mudas sob sombrite com 50% de sombreamento foram melhores, seguidas daquelas com 90%, 30% e pleno sol.

The present work aimed to determine the best shading levels for the growth of coffee seedlings. The experiment was carried out at the Agriculture Department of the Federal University of Lavras. Coffee seedlings (Coffea arabica L.) were grown under four shading levels: seedlings in full sunshine, and under 30%, 50%, and 90% shading. The treatments were arranged in a randomized block design, whith four replications. The experiment was run to the third/fourth leaf pair. Afterwards, the following analyses were performed: height, stem diameter, number of leaf pairs, root dry weight, shoot dry weight, and leaf area. Results showed the seedlings develop best under 50% shading, then 90 and 30% shading, and lastly under full sunshine.