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This study aimed to measure the effects of rates of plant growth regulator trinexapac-ethyl on the development of the aerial, root parts and yield components of corn. The experiments were conducted in a greenhouse: one assay was aimed at evaluating the growth and development of the plant, in a 4 x 4 factorial arrangement, with four rates of trinexapac-ethyl (0, 125, 250 and 375 g of i.a. ha-1) and four assessment periods (14, 21, 28 and 35 days after application), and the other was aimed at assessing the yield productions for corn in response to the same four rates of the regulator. The present study demonstrates that grain yield per plant was reduced with the use of trinexapac-ethyl, due to decrease in spike length, number of kernels in each row and hundred grain mass. The use of trinexapac-ethyl does not change the cycle of corn, but increases stem diameter and chlorophyll index, and reduces the plant height and spike insertion height, leaf area, dry mass of aerial part, dry mass and volume root system. The trinexapac-ethyl changes the size of the corn plants, enabling new spatial arrangements. Key words: Leaf architecture, yield components, plant growth, plant growth regulator, Zea mays L.

O objetivo deste trabalho foi avaliar a qualidade comercial dos graos de diferentes hibridos comerciais de milho em funcao do teor de agua nos mesmos durante a colheita. O trabalho foi conduzido em Astorga – PR, durante o periodo da safrinha de 2007 e da safra de verao de 2007/2008, sendo tres hibridos avaliados em cada periodo. As amostras de graos foram colhidas em cinco epocas distintas com cinco repeticoes e submetidas a determinacao do teor de agua pelo metodo da estufa a 103 ± 1 oC por 72 h. Posteriormente, as amostras foram passadas por peneiras metalicas de crivo circular de 4,76 mm de diâmetro e, em seguida, os residuos foram separadas manualmente nas porcoes de impurezas, graos avariados e graos carunchados. Os resultados obtidos foram submetidos a analise de variância e de regressao sob o delineamento inteiramente casualizado. Os percentuais de impurezas foram maiores nos teores de agua de colheita mais elevados, enquanto que os percentuais de graos avariados foram menores, independente do hibrido e do periodo avaliado. O grau de infestacao se elevou linearmente com a reducao do teor de agua nos graos de milho, em todos os hibridos. Os teores de agua entre 22% e 26% (b.u.) proporcionaram melhor qualidade fisica e sanitaria dos graos de milho, considerando esta como a faixa ideal de teor de agua para a colheita dos graos de milho.

This study aimed to evaluate the adaptability and phenotypic stability of 10 soybean genotypes in 12 environments in Paraná state by using the additive main effects and multiplicative interaction analysis (AMMI) and Eberhart and Russell models. The assays were conducted in a randomized complete block design with three replicates, in the 2010/2011 season in four locations in Paraná state (Assaí, São Pedro do Ivaí, Cornélio Procópio, and Marilândia do Sul), and with three sowing dates (15/-20/10/10; 29/10-03/11/10; 15/-20/11/10). The cultivars tested with Roundup Ready® technology included SYN 1049, SYN 1152, SYN 1059, SYN 3358, SYN 1163, SYN 1157, V-MAX, FT Campo Mourão, BMX Potência, and SYN 9070. The yield character was analyzed. Data were submitted to analysis of variance and the adaptability and stability were then analyzed. The results of the AMMI and Eberhart and Russell models were somewhat consistent for the stability parameter only. The AMMI analysis was able to capture 66% of the variance associated with residue no additives, of which 43.18% was retained in the first principal component of interaction and 23.58%, in the second component. This is sufficient to explain the genotype × environment interaction. The SYN 1059, SYN 1163, and VMAX genotypes are distinguished by their considerably higher yield and productive adaptation. In the AMMI analysis, the cultivar SYN 1163 showed commercial promise among the other cultivars for high grain yield performance, adaptation, and response predictability.

O objetivo deste trabalho foi avaliar a incidência de fungos dos gêneros Aspergillus, Fusarium e Penicillium e as contaminações com micotoxinas em grãos de cinco híbridos comerciais de milho em função da umidade de colheita. O trabalho foi conduzido em Astorga, Estado do Paraná, durante o período da ‘safrinha’ de 2007 e da safra de ‘verão’ de 2007/2008. As amostras de grãos, colhidas em cinco épocas distintas e em cinco repetições, foram submetidas à determinação de umidade pelo método da estufa a 103 ± 1ºC por 72h. O teste de sanidade Blotter test e a quantificação micotoxinas (método da cromatografia em camada delgada) foram efetuados, utilizando-se um delineamento inteiramente casualizado. Os resultados obtidos foram submetidos à análise de variância e de regressão. O gênero Fusarium apresentou crescimento linear da incidência, em função do aumento da umidade, enquanto os gêneros Aspergillus e Penicillium tiveram suas incidências reduzidas. Observou-se que é possível a produção de aflatoxinas, associadas aos grãos de milho, ainda no campo, e que a antecipação da colheita, seguida de secagem imediata, assegura a qualidade sanitária dos grãos de milho. The objective of this work was to evaluate the incidence of Aspergillus, Fusarium and Penicillium fungi, and the contaminations with mycotoxins in grains of five corn commercial hybrids due to harvest humidity. The work was conducted in Astorga, Paraná State, during the autumn/fall harvest of 2007 and the summer harvest of 2007/2008. The corn grain samples were collected in five distinguished periods and also in five replications, subjected to humidity content determination at an oven heated to 103 ± 1ºC for 72h. The blotter test and the mycotoxins presence were evaluated by thin layer chromatography, using a completely randomized design. The data were submitted to analyses of variance and regression. The genera Fusarium presented linear increasing incidence due to humidity increasing, whereas Aspergillus spp. and Penicillium spp. had their incidences decreased. It was observed that the possible production of aflatoxins, associated to corn grains, still in the field, and, that the anticipation of the crop harvesting, followed by immediate drying assures the sanitary quality of the corn grains.