Nitrogen doses and weed control via intercropping with gliricidia for corn production

Many studies have demonstrated the beneficial influence of nitrogen doses on corn dry grain yield and green ear yield. Due to a growing concern with environmental degradation, many agricultural practices, adopted in the past, are being reexamined. With regard to weed control, strategies that employ mechanical control, including intercrops, are being the object of renewed interest. The purpose of this study was to evaluate the effects of the application of nitrogen doses (0, 40, 80, and 120 kg N ha-1; as ammonium sulfate) and weed control on the growth, green ear yield, and grain yield of the AG 1051 corn cultivar. A randomized block experimental design with split-plots and nine replications was adopted. In addition to nitrogen rates, the AG 1051 cultivar was submitted to the following treatments, applied to subplots: no weeding, two hoeings (at 20 and 40 days after sowing), and intercropping with gliricídia (Gliricidia sepium). Gliricidia was sowed at corn planting, between the corn rows, using two seedlings per pit, in pits spaced 0.30 m apart. Gliricidia did not provide weed control, and gave plant growth, green ear yield and grain yield values similar to the no weeding treatment. However, regarding the number of mature ears got, intercropping with gliricidia did not differ from the two-hoeing treatment. Weed control did not have an effect on plant height and number of marketable, husked green ears, with the application of 120 kg N ha-1; indicating that nitrogen improved the corn's competitive ability. The two-hoeing treatment provided the best means for total green ears weight, number of marketable husked ears, both unhusked and husked marketable ear weight, grain yield and its components than the other treatments. Nitrogen application increased corn growth, green ear yield, and grain yield, as well as weed green biomass, but reduced the stand and growth of gliricidia

Os partidos políticos brasileiros realmente não importam?

Há décadas a constatação corrente no Brasil é de que os partidos pouco importam para explicar o comportamento dos eleitores brasileiros. Entretanto, esse cenário de baixa identificação partidária contrasta com a observação de que, ao menos para as eleições presidenciais a competição eleitoral tem se estruturado em torno de duas organizações partidárias: PT e PSDB. O objetivo deste artigo é demonstrar que mesmo que os partidos de fato não estejam internalizados em termos de identidade partidária, estamos vivenciando importante movimento no sentido de uma divisão do eleitorado entre as duas principais organizações políticas em termos de simpatia partidária, redundando na estruturação de um sistema bipartidário ao nível da disputa nacional. Com base nas respostas dos entrevistados do ESEB 2002, 2006 e 2010 sobre as eleições presidências verificamos que nesses pleitos as simpatias eleitorais pelo PT e PSDB se mostraram um dos principais componentes de explicação do voto nos candidatos. Este artigo também destacou que apesar das simpatias partidárias serem uma heurística utilizada para decisão do voto entre os eleitores com maior escolaridade, foi possível observar que mesmo entre os menos escolarizados essa variável foi fundamental para explicar o voto, evidenciando que mesmo entre eleitores com menor conhecimento político, os partidos têm auxiliado na decisão do voto.<br>For decades the conventional wisdom in Brazil has been that political parties do not matter in explaining the behavior of Brazilian voters. However, this scenario of low partisan identification contrasts with the observation that, at least for presidential elections, electoral competition has been structured around two party organizations: those of the PT and PSDB. The aim of this article is to demonstrate that, even if parties are in fact not internalized in terms of party identification, we are witnessing an important division between two principal political organizations in terms of party preference, reflecting the emergence of a bipartisan system at the national level. On the basis of responses of interviewees about the presidential elections in the CSES-ESEB of 2002, 2006, and 2010, we see that in these elections the electoral affinities for the PT and PSDB are some of the principle components of an explanation of the vote. This article also emphasizes that despite the fact that party preference is more pronounced as a means of candidate selection for those with a high degree of education, it is possible to observe that even among those with less education this variable is fundamental to explain the vote, providing evidence that even for voters with less knowledge of politics, the parties are helping to structure the voting decision