Controlling weeds with natural phytotoxic Substances (NPS) in direct seeded soybean

Field trials on weed control in direct seeding with the use of natural phytotoxic ingredients (NPI) were carried out from 2011 to 2013 at the Agricultural Research Institute of Paraná state, Brazil (IAPAR). Soybean was direct seeded into residues of precrop black oats (\textit{Avena strigosa)}. In a split-plot trial the whole-plot treatment consisted of two different weed densities. In the eight subplot treatments the effects of "natural phytotoxic ingredients" (NPI) on weed control was evaluated. The two NPI formulations used in the experiment contained 50 L/ha Pine Oil (formulation ``Pine Oil'') or 50 L/ha d-Limonene (formulation ``Limonene''), both combined with 50 kg/ha NaCl. These formulations were applied once, twice, or three times in a weekly interval. A weedy and a manually hoed clean plot was used as control treatment. The single application treatments of Limonene and Pine Oil scored 41 \% and 52 \%, two applications 53 \% and 56 \% and three applications 61 \% and 67 \% respectively, with a 70 \% rating being considered an acceptable result in conventional herbicide testing. The grain yield for the 'clean' control treatment was highest with 4.07 t/ha and lowest for the untreated control treatment with 2.61 t/ha. The limonene treatments yielded 3.07, 3.22, 3.57, and the pine oil treatments 2.68, 3.00 and 2.96 t/ha with one, two and three applications respectively. The lower grain yields of pine oil despite slightly better performance in the weed control rating can be explained by phytotoxic effects of applied product which came in contact with soybean crop during application

Cover crops preceding the wheat crop

ABSTRACT - After harvesting of summer crops and before wheat planting, in the temperate region of southern Brazil, there is a time in which it could be possible grows short cycle cover crops. The objective was to evaluate some cover crop species during this period and its effect on wheat crop. The following treatments, in the years 2011 to 2013, were evaluated: fallow – bare soil (check), sunflower (Helianthus annuus), sunnhemp (Crotalaria juncea), forage radish (Raphanus sativus), pea forage (Pisum sativum) and buckwheat (Fagopyrum esculentum). It was also evaluated the effect of time - 0, 15 and 30 days - between the formation of the mulching and the planting of wheat. In the average of the three years the highest wheat yield was obtained in sunflower mulch. The best wheat early development was observed in radish forage and pea forage mulches. No effect of time after the formation of mulch on wheat yield was observed but there was a significant reduction in the number of emerged wheat plants in pea forage mulch and reduction in the weight of the grains in pea and radish residues when the wheat was planted immediately after the mulch formation.After harvesting of summer crops and before wheat planting, in the temperate region of southern Brazil, there is a time in which it could be possible grows short cycle cover crops. The objective was to evaluate some cover crop species during this period and its effect on wheat crop. The following treatments, in the years 2011 to 2013, were evaluated: fallow – bare soil (check), sunflower (Helianthus annuus L.), sunnhemp (Crotalaria juncea L.), forage radish (Raphanus sativus L.), pea forage (Pisum sativum L.) and buckwheat (Fagopyrum esculentum Moench). It was also evaluated the effect of time - 30, 15 and 0 days - between the formation of the mulching and the planting of wheat. In the average of the three years the highest wheat yield was obtained in sunflower mulch. The best wheat early development was observed in sunflower, radish forage and pea forage mulches. No effect of time after the formation of mulch on wheat yield was observed but there was a significant reduction in the number of emerged wheat plants in pea forage mulch when the wheat was seeded immediately after the mulch formation

Introdução

«A decisão do controle químico de infestantes deve ser fundamentada em informações científicas que permitam sustentabilidade técnica, ambiental, social e econômica. Na ausência de informações do impacto de cada espécie vegetal sobre a cultura, normalmente toma-se a decisão de manejo com base no nível de infestação (densidade, massa) de cada espécie presente na área, ou seja, decide-se pelo controle das plantas presentes em maiores densidades. Nem sempre esta decisão é a mais correta, pois algumas espécies são muito competitivas e, mesmo sob baixas infestações, causam prejuízos muito acentuados no rendimento da cultura. Esses fatos justificam a necessidade de se pesquisar o nível crítico de dano (NCD) das plantas daninhas nas culturas»

Controle alternativo do gorgulho-do-milho, Sitophilus zeamais, em armazenamento com subprodutos do processamento do xisto, no Paraná, Brasil.

Estima-se que no Brasil as perdas anuais causadas por pragas durante o armazenamento de grãos equivalem a 10% da produção. O mercado tradicional fornece agrotóxicos para o controle, mas os produtores de base ecológica têm poucas alternativas. Assim, foi objetivo do trabalho verificar a eficácia dos subprodutos do xisto no controle de S. zeamais em sementes de milho. Empregou-se pós de xisto retortado, finos de xisto, calxisto e cinza de xisto (2 e 5 Kg/1000 Kg de sementes), terra diatomácea e testemunha não tratada. Os ensaios foram conduzidos em delineamento inteiramente casualizado, três repetições por local e época de avaliação. A mortalidade foi verificada bimestralmente até 180 dias. Verificou-se o efeito dos tratamentos através da ANOVA e diferença de médias por L.S.D. (Fisher modificado), ao nível de P<0,05. Cinza de xisto mostrou-se eficiente até os 180 dias de armazenamento. Não houve influência negativa dos pós de rochas na germinação e vigor. Concluiu-se que cinza de xisto possui grande potencial como alternativa de controle de S. zeamais em propriedades de base ecológica

Tratamento de milho em grão e espiga com pós inertes no controle do gorgulho do milho Sitophilus zeamais.

O presente trabalho objetivou verificar os efeitos de tratamentos alternativos de sementes de milho variedade (IPR 114), armazenadas a granel e em espigas ensacadas, no controle do gorgulho do milho (Sitophilus zeamais Mots). Os tratamentos consistiram em 5 kg pó mg-1 de milho de cinza de xisto, cinza de madeira e terra diatomácea (tratamento padrão). Como testemunha, foram utilizadas sementes não tratadas. O trabalho foi realizado em dois locais diferentes simultaneamente, nas cidades de São Mateus do Sul e Ponta Grossa (PR), durante os meses de abril a novembro de 2009. As variáveis analisadas foram o número de insetos vivos, germinação, vigor e grau de infestação, para o milho armazenado em espiga, e número de gorgulhos vivos e infestação para o milho em grão. No milho a granel, os pós inertes foram eficazes no controle do S. zeamais, a partir dos 30 dias de armazenamento. No armazenamento em espigas, os resultados não foram conclusivos quanto a eficiência dos pós

Oat tillering and tiller traits under different nitrogen levels in an eucalyptus agroforestry system in Subtropical Brazil

In oat production, tillering persistence is the determinant of one important yield component, namely the number of panicles. This process is highly influenced by the inter- and intraspecific interactions of the agroecosystem, which in turn depend on agronomic practices. The hypothesis of this research is that nitrogen does not increase oat tolerance to negative interference from trees, so oat tillering persistence in grain production remains un-modified by nitrogen at distances relative to the eucalyptus tracks, within the alley cropping agroforestry system (ACS). Thus, nitrogen should not be used to increase oat yield potential in these systems. The objective of this study was to determine how the tillering persistence for grain production and oat (Avena sativa L. cv. 'IPR 126') tiller traits were influenced by nitrogen levels (12 and 80kg N ha-1) at five equidistant positions between two adjacent eucalyptus (Eucalyptus dunnii Maiden) double line tracks [20m (4mx3m)] in ACS and traditional no-till agriculture in subtropical Brazil. The experiment was conducted in a split-block randomized block design with four replicates. The goal was to evaluate the oat phytomass, tiller-to-main shoot phytomass ratio, tillers per main shoot, grain yield and tiller-to-main shoot grain yield ratio. The oat tillering persistence for grain production is dependent on different nitrogen levels at distances relative to adjacent eucalyptus tracks and therefore, different nitrogen levels should be used in those areas, to improve oat yield potential inside ACS in subtropical Brazil

Oat growth under different nitrogen doses in eucalyptus alley cropping system in subtropical Brazil

Plant growth analysis was performed to determine how oat (Avena sativa L. cv. IPR 126) cultivated for grain responds to the eucalyptus (Eucalyptus dunnii Maiden) alley cropping system (ACS) in subtropical Brazil. The hypothesis of this work was that oat growth response is not modified by nitrogen at distances relative to 4 year old eucalyptus tracks in the ACS. The objective of this study was to determine how the oat growth was influenced by nitrogen doses (12 and 80 kg N ha-1) at five equidistant positions between two adjacent eucalyptus double line tracks [20 m (4 m x 3 m)] in ACS and traditional no-till farming. The experiment was conducted in a split-block randomized block design with four replicates. It was evaluated the oat relative growth rate, unit leaf rate, leaf weight fraction, panicle phytomass, panicle relative filling rate and grains-to-panicle ratio. Nitrogen doses altered the growth response differently in positions relative to the adjacent eucalyptus tracks; therefore, different nitrogen doses should be used in positions relative to the trees to improve oat growth in ACS in Subtropical Brazil