Efecto de abonos verdes y fuentes de fósforo en la morfología y rendimiento de las plantas de maíz

The aim of this study was to evaluate the behavior of the maize crop in succession to different species of green manures, with different sources of phosphorus and their interaction. A completely randomized block in a split plot design was used, with three main treatments and seven secondary treatments, with three replications. The treatments consisted of three sources of phosphorus (plots) and six species of green manures (subplots). It was used maize plants of cultivar Premium Flex®. It were evaluated plant height, leaf number, stem diameter, leaf area index, leaf and stem dry weight,  specific leaf area, ear number, mass of one hundred grains, stand and yield. There was no interaction effect on all traits. However, the dry weight of stem and seed yield showed significant difference between the sources of phosphorus, with positive results for both sources of phosphorus in relation to the control. This suggests that the shoot dry weight is responsive to the presence of phosphorus. It was observed that the phosphate rock has potential to achieve crop yield similar to that obtained with superphosphate.El objetivo de este estudio fue evaluar el comportamiento de las plantas de maíz en sucesión a diferentes especies de abonos verdes, con diferentes fuentes de fósforo y su interacción. El diseño experimental utilizado fue bloques al azar con parcelas divididas, con tres tratamientos principales y siete tratamientos secundarios con tres repeticiones. Los tratamientos consistieron en tres fuentes de fósforo (parcelas) y seis especies de abonos verdes (subparcelas o parcelas secundarias). Se utilizaron plantas de maíz de la variedad premium Flex®. Fueron evaluadas la altura de planta, número de hojas, diámetro del tallo, índice de área foliar, masa seca de hojas y tallo, área foliar específica, número de mazorcas, peso de cien granos, stand y productividad. No se observó efecto de interacción en ninguna de las características evaluadas. Sin embargo, el peso seco del tallo y el rendimiento de grano mostró diferencias significativas entre las fuentes de fósforo, presentando resultado positivo para ambas fuentes de fósforo en relación con los resultados del control. Esto sugiere que la producción de masa seca de la parte aérea de la planta es sensible a la presencia de fósforo. Se encontró que el fosfato natural presenta potencial de lograr rendimiento similar a lo obtenido con superfosfato simple.O objetivo deste trabalho foi avaliar o comportamento de plantas de milho em sucessão a diferentes espécies de adubos verdes, com diferentes fontes de fósforo e sua interação. Foi utilizado delineamento experimental de blocos ao acaso com parcelas subdivididas, sendo três tratamentos principais e sete tratamentos secundários, com três repetições. Os tratamentos constaram de três fontes de fósforo (parcelas) e seis espécies de adubos verdes (subparcelas). Foram utilizadas plantas de milho da cultivar Premium Flex®. Foram avaliados a altura de plantas, número de folhas, diâmetro de colmo, índice de área foliar, massa seca de folhas e colmo, área foliar específica, número de espigas, peso de cem grãos, estande e produtividade. Não houve efeito de interação em nenhuma das características avaliadas. No entanto, a massa seca de colmo e a produtividade de grãos apresentaram diferença significativa entre as fontes de fósforo, apresentando resultados positivos para ambas as fontes de fósforo em relação à testemunha. Isso sugere que a produção de massa seca da parte aérea seja responsiva a presença de fósforo. Verificou-se que o fosfato natural apresenta potencial de alcançar rendimento agrícola semelhante ao obtido com superfosfato simples

Qualidade pós-colheita de maçãs tratadas com óleos vegetais

The coating is a technique that has been used to preserve the quality and extend the shelf life of fruit. The objective of this research was to evaluate the evolution of the mass loss and quality characteristics of apple fruit (Malus domestica Borkh.) treated with vegetable oils during cold storage. Two experiments were conducted, using apples from cvs. Maxi Gala and Fuji Suprema, and vegetable oils of neem and soybean. The main effect of vegetable oil applied in post-harvest is in reducing perspiration of the fruits with consequent reduction in mass loss. In general, the best effect occurred with the use of the highest dose tested (4%). The vegetable soybean oil is more efficient than the neem fruit in apple coating. Vegetable oils had little or no effect on characteristics such as soluble solids, titratable acidity, firmness and color, with varying responses for each experiment, indicating little change in breathing and retardation of ripening/senescence of fruits.O revestimento é uma técnica que tem sido utilizada para preservar a qualidade e estender a vida de prateleira de frutos. O objetivo desta pesquisa foi avaliar a evolução da perda de massa e de características qualitativas de frutos de macieira (Malus domestica Borkh.) tratadas com óleos vegetais durante o armazenamento refrigerado. Foram realizados dois experimentos, utilizando maçãs das cvs. Maxi Gala e Fuji Suprema, e óleos vegetais de nim e de soja. O principal efeito do óleo vegetal aplicado em pós-colheita está na redução da transpiração dos frutos, com consequente redução da perda de massa. Em geral, os melhores efeitos ocorreram com a utilização da maior dose testada (4%). O óleo vegetal de soja é mais eficiente que o de nim no revestimento de frutos de maçãs. Os óleos vegetais apresentaram pouco ou nenhum efeito em características como sólidos solúveis, acidez titulável, firmeza de polpa e coloração, com variação de respostas para cada experimento, indicando pouca alteração na respiração e atraso da maturação/senescência dos frutos

Extração e imobilização de nutrientes em videiras ‘isabel precoce’ enxertadas em diferentes porta-enxertos e cultivada em sistema orgânico

This study evaluated the immobilization and nutrient uptake in an experimental organic vineyard of ‘Early Isabella’ grapevines in the Midwestern region of Parana State, Brazil. The experimental design was implemented in randomized blocks with two different rootstocks ‘Paulsen 1103’ and ‘VR 043-43’ along with four replications and three plants per plot. Five years after planting, one plant per plot was completely removed from the soil and then subdivided into root, stem and canes. The remaining plants in the area were managed until harvest. The sectioned parts and clusters were dried in a forced air oven at 65°C. The dry mass was subsequently determined and mineral analyses were performed. The amounts of nutrient uptake immobilized by ‘Early Isabella’ grapevines with yields between 9.9 and 16.6 t ha-1 were 64.9, 19.0, 156.9, 45.8 and 12.7 kg ha –1 for N, P, K, Ca, Mg, respectively, when grafted on Paulsen ‘1103’ and 112.8, 29.3, 260.8, 82.3 and 26.0 kg ha-1, respectively, when grafted on ‘VR 043-43’.O objetivo do trabalho foi avaliar a imobilização e extração de macronutrientes em um vinhedo experimental de cultivo orgânico de videiras cv. Isabel Precoce na região Centro-Oeste do Paraná. O delineamento experimental foi em blocos casualizados, com dois tratamentos (porta-enxertos: Paulsen ‘1103’ e ‘VR 043-43’), quatro repetições e três plantas por parcela. Cinco anos após o plantio, uma planta por parcela foi totalmente removida do solo, sendo que posteriormente as videiras foram subdivididas em três partes: raiz, caule e ramos do ano. A partir das plantas remanescentes no campo, realizou-se a colheita dos cachos. Para as avaliações, as plantas e os cachos foram secos em estufa de ar forçado a 65°C. Posteriormente, determinou-se a massa seca e se realizaram análises do teor dos macronutrientes dos tecidos vegetais Pelos resultados obtidos, verificou-se que as quantidades de nutrientes imobilizadas e exportadas pela videira cv. Isabel Precoce com produtividade entre 9,9 e 16,6 t ha-1, em função do porta-enxerto foram para N, P, K, Ca, Mg, respectivamente de 64,9; 19,0; 156,9; 45,8 e 12,66 kg ha-1 quando enxertadas sobre o Paulsen ‘1103’ e de 112,8; 29,3; 260,8; 82,3 e 26,0 kg ha-1 quando enxertadas sobre o ‘VR 043-43’

Susceptibility of pear cultivars to entomosporiosis

The entomosporiosis is considered a major disease of pear in Brazil, one of the most responsible for premature defoliation in plants. The objective of this study was to characterize the susceptibility of pear tree cultivars Housui, Cascatense, Packam’s Triumph and Rocha for the intensity of leaf spot entomosporiosis. The experiment was conducted at the experimental orchard of the State University of the Midwest (Unicentro), Paraná State, Guarapuava County, Brazil during the 2013/2014 season. The incidence and severity were monitored during 77 days from the beginning of the symptoms in 25 leaves of 8 plants per cultivar. With these data the following variables were calculated: early onset of symptoms (EOS), maximum incidence and severity (Imax and Smax) and the Area Under the Incidence Progress Curve (AUIPC) and Severity (AUSPC). In addition, the data were checked for severity and the best adjustments for the monomolecular, logistic and exponential models were tested. From these results it is clear that all the studied cultivars are susceptible to leaf spot entomosporiosis, however, Housui pear cultivar presented higher endurance while Rocha and Cascatense cultivars presented greater susceptibility to this disease

Antifungal activity of plant extracts on Phaeomoniella chlamydospora

The decline and death of the vine has become an obstacle to world wine production. Among the causative agents highlights the Phaeomoniella chlamydospora, causal agent of Esca and Petri disease. Plant extracts may become a viable option control considering their fungistatic and/or fungicide substances. The objective of this work was to verify the potential of the aqueous extracts of plants on the control of Phaeomoniella chlamydospora comparing to other products. The following treatments were applied: sulfur, mancozeb, difeconazole, pyraclostrobin, tebuconazole, chitosan, Bacillus subtilis, Trichoderma harzianum,and extracts of india flowers, cinnamon bark, dried leaves of rosemary and lemon grass. The treatments were added in PDA culture medium, previously autoclaved at 120o for 20 min. Disc of 5 mm diameter of P.chlamydosporacolony were transferred to the center of Petri dishes and kept at 20∘C in the dark. The experimental design was completely randomized with five replications. It was evaluated the mycelial growth at five, eight and fourteen days after the installation of the experiment, obtaining the area under curve of the mycelial growth (AUCMG). The clove India extracts, cinnamon and rosemary, proved to be a control option considering their effect in the decrease of AUCMG compared to the control

Antifungal activity of plant extracts on

The decline and death of the vine has become an obstacle to world wine production. Among the causative agents highlights the Phaeomoniella chlamydospora, causal agent of Esca and Petri disease. Plant extracts may become a viable option control considering their fungistatic and/or fungicide substances. The objective of this work was to verify the potential of the aqueous extracts of plants on the control of Phaeomoniella chlamydospora comparing to other products. The following treatments were applied: sulfur, mancozeb, difeconazole, pyraclostrobin, tebuconazole, chitosan, Bacillus subtilis, Trichoderma harzianum,and extracts of india flowers, cinnamon bark, dried leaves of rosemary and lemon grass. The treatments were added in PDA culture medium, previously autoclaved at 120o for 20 min. Disc of 5 mm diameter of P.chlamydosporacolony were transferred to the center of Petri dishes and kept at 20∘C in the dark. The experimental design was completely randomized with five replications. It was evaluated the mycelial growth at five, eight and fourteen days after the installation of the experiment, obtaining the area under curve of the mycelial growth (AUCMG). The clove India extracts, cinnamon and rosemary, proved to be a control option considering their effect in the decrease of AUCMG compared to the control