Átila Francisco Mógor

Occurrence of Lysiphlebus testaceipes (Cresson, 1880) (Hymenoptera: Braconidae: Aphidiinae) parasitizing Aphis forbesi Weed, 1889 (Hemiptera: Aphididae) in the strawberries crop in the metropolitan Region of Curitiba, Parana, Brazil

aPrograma de Pos-graduacao em Agronomia Producao vegetal, Departamento de Fitotecnia e Fitosanitarismo, Universidade Federal do Parana – UFPR, Rua dos funcionarios, 1540, CEP 80035-050, Curitiba, PR, Brazil bDepartamento de Patologia Basica, Universidade Federal do Parana – UFPR, Jardim das Americas, CEP 81531990, Curitiba, PR, Brazil cDepartamento de Ciencias Biologicas, Universidade Federal do Espirito Santo – UFES, Av. Marechal Campos, 1468, CEP 29.043-900, Vitoria, ES, Brazil dDepartamento de Fitotecnia e Fitossanitarismo, Universidade Federal do Parana – UFPR, Rua dos funcionarios, 1540, CEP 80035-050, Curitiba, PR, Brazil *e-mail: emiagro@yahoo.com.br

Rizobactérias no crescimento e na produtividade da cebola

The association of plants with rhizobacteria can enhance plant growth, reducing production costs. Benefic rhizobacteria can stimulate plant growth being an alternative for production of onions. This research assesses the impact of applying rhizobacteria in the growth and productivity of cv. Bola Precoce onions. The study was conducted in the Experimental Station of Epagri, Ituporanga, SC, Brazil in 2008. The experimental design was in random blocks with five repetitions using Pseudomonas spp. W6, B Bacillus megaterium W19 e Bacillus cereus UFV40 rhizobacteria, microbiolized singly in seeds or in a formula together with non-treated control. The treatments involving rhizobacteria application yielded higher heights, diameter of pseudo-trunk and number of leaves in the plants assessed at 90 days after transplant. All the plants which received treatments with rhizobacteria presented better results considering the fresh weight and yield of bulb in relation to the control. The mass of bulbs were positively affected by the treatments, especially for Bacillus megaterium W19.

The interaction between mycorrhizal inoculation, humic acids supply and elevated atmospheric CO 2 increases energetic and antioxidant properties and sweetness of yellow onion

The combined application of humic substances and mycorrhizal inocula under increased CO2 in the air is a promising horticultural technique for improving the quality of greenhouse-grown onion seedlings. The objective of this study was to evaluate if the development and qualitative characteristics of bulbs from the yellow onion Allium cepa L. Alfa São Francisco improved with the application of the abovementioned agronomic, biotic, and environmental factors. The lowest dry matter was achieved in bulbs of onions not inoculated with mycorrhizal fungi, non-amended with humic acids (HA), and grown at ambient CO2. Mycorrhizal inoculation significantly increased bulb biomass in plants cultivated at ambient CO2, and not fertilized with HA, which may be a consequence of the enhanced acid phosphatase activity in roots. The application of HA always increased bulb dry matter, which were more evident at elevated rather than ambient CO2 conditions and correlated with improved acid phosphatase activity in the plants at elevated CO2. Mycorrhizal inoculation, HA supplementation, and elevated CO2 in the air had an additive effect of increasing the content of soluble sugars, proteins, and phenolics in bulbs. While high levels of sugars and proteins enhanced the energetic value of onions, the increase in phenolics improved their antioxidant properties. The triple interaction between mycorrhization, HA fertilization, and elevated CO2 also increased the ratio between soluble solids and total titratable acidity, which may enhance the perception of sweetness and make onions more pleasant for consumption.

Strategies for Characterization of Agriculturally Important Bacteria

The technology of plant production always faced fast-growing food and energy demands, but driven by a new approach, the answer for those demands must be socially and environmentally conscious. In this way we have a very powerful tool, bacteria, that benefit the plants. Therefore, to use that natural resource, some aspects must be observed, such as carrying out isolation of strains directed to the use (when possible) and correctly identify the strain used, not only by morphological techniques but also by molecular techniques, looking for the necessary biosafety for those who will use the developed technology. The characterization of strains will define the potential use that we want to follow: biofertilizer, phytostimulators, or biocontrol agents. After identifying the main characteristics of bacteria, there is a universe of possibilities regarding the plant interaction and bacteria, such as the signal recognition, penetration, and establishment, and whether the bacteria are endophytic, epiphytic, or rhizospheric. Before the immersion on the complexity of the issue, our aim was to contribute for the characterization of agricultural interest of bacteria, with attention to the desired characteristics, and discuss the mechanisms within each line of action – biofertilizer, phytostimulators, or biocontrol agents.

Desempenho de cultivares nacionais de batata para produtividade de tubérculos

O objetivo deste trabalho foi verificar o desempenho dos cultivares de batata nacionais BRS Ana e BRS Clara, em comparacao com os cultivares importados Agata e Asterix, em relacao a produtividade de tuberculos. Os experimentos foram realizados no municipio de Canoinhas, SC. Foram avaliados quatro cultivares de batata: BRS Ana, BRS Clara, Asterix e Agata. O delineamento experimental foi em blocos casualizados, com quatro repeticoes. As parcelas continham quatro linhas com 20 plantas em cada linha. Cento e dez dias apos o plantio foi realizada a colheita e, os tuberculos de cada parcela, avaliados para caracteres relacionados com a produtividade de tuberculos. Os dados foram submetidos a analise de variância e agrupamento de medias, por Skott & Knott, a 5% de probabilidade. Os cultivares de batata nacionais BRS Ana e BRS Clara foram mais produtivos do que os importados Asterix e Agata; no entanto, sao mais tardios, quanto ao ciclo vegetativo.

Teores de clorofila em cultivares de tomateiro submetidas a aplicações foliares de magnésio

Although the foliar nutrients application is well disseminated in horticulture, the technology is still controversial, since the products efficiency is related to the characteristics of the formulations, especially the sources of nutrients used. Thus, this study aimed at identifying changes in chlorophyll contents, by using the colorimetric method and a chlorophyll meter, as well as in the Mg content in tomato plant leaves, as related to foliar applications of solutions containing Mg (OH) 2 or MgCl 2 . Two tomato cultivars were subjected to fertigation with low Mg addition. The data from the chlorophyll meter were corroborated by the colorimetric method, indicating that the solutions containing 1.0 mL L -1 and 2.0 mL L -1 of a suspension concentrate (300 g L - 1 of Mg, as Mg(OH) 2 ) and the solution containing 3.75 mL L - 1 of MgCl 2 were effective in increasing the chlorophyll contents, resulting in the Mg absorption and metabolization. The solution containing 7.5 mL L - 1 of MgCl 2 caused fitotoxicity and reduced the chlorophyll contents, although promoting a higher Mg content in leaves.

Agronomic performance of cultivars of organic onion in two harvest times

The growing demand for organic products and the need to plant onions (Allium cepa L.) in the town of Pinhais, Brazil at different times of the year generated this study in the Organic Horticulture Experimental Station of Canguiri-Federal University of Parana, Pinhais, Brazil. The objective was to evaluate the agronomic performance of seven cultivars of open-pollinated onion in an organic system in two planting seasons (January and September) different than traditional times (April and June). The experimental design was completely randomized in a 7x2 factorial scheme with three replicates: Franciscana IPA-10, Vale Ouro IPA-11, Brisa IPA-12, Alfa Sao Francisco (Cycle VIII), Alfa Sao Francisco -RT (Thrips tabaci-resistant genotype assessment - Embrapa Semiarid) and BR-29. The results were evaluated for homogeneity by Bartlett�s test and treatment means were compared by Tukey�s test at a significance level of 5%. The variables assessed at the start of bulb formation and harvest were stem height, fresh and dry leaf weight, leaf number and scape diameter. At harvest we measured dry and fresh mass of the bulb, bulb type according to the diameter and productivity. The cultivars Alfa Sao Francisco and Alfa Sao Francisco-RT produced higher values of dry mass and productivity in January

Teor e composição de óleo essencial de rizomas de gengibre (Zingiber officinale Roscoe) após diferentes períodos de secagem

A producao de gengibre no Parana concentra-se no municipio de Morretes, ocupando uma area de plantio de aproximadamente 300 ha. O objetivo deste trabalho foi avaliar o teor e a composicao do oleo essencial de rizomas de gengibre produzidos em Morretes e submetidos a diferentes periodos de secagem em temperatura ambiente. O delineamento experimental foi inteiramente casualizado, em esquema fatorial 5 x 5, com quatro repeticoes (quatro plantas por repeticao), avaliando cinco procedencias e cinco periodos de secagem a temperatura ambiente (0, 15, 30, 45 e 60 dias). As extracoes de oleo essencial foram realizadas por hidrodestilacao em aparelho graduado Clevenger durante tres horas e a analise dos constituintes foi realizada por meio de cromatografia em fase gasosa acoplada a espectrometria de massas. A secagem de rizomas de gengibre em temperatura ambiente por ate 60 dias resultou na diminuicao de teores de oleo essencial na maioria das procedencias. Os constituintes geranial e o neral apresentaram maior concentracao em todas as procedencias e tiveram teores superiores com o aumento nos periodos de secagem. Os teores de geraniol e acetato de geranila foram inferiores apos a secagem em todas as procedencias, assim como eucaliptol, canfeno, zingibereno e β-bisaboleno na maioria das procedencias.

Biostimulant properties of cyanobacterial hydrolysate related to polyamines

Developing new and natural sources of plant growth promotors is essential to ensure the safe and sustainable production of vegetables for human consumption. In recent years, the potential of microalgae as plant biostimulants has been investigated. Arthrospira platensis (Spirulina platensis) biomass is a recognized protein source and its enzymatic hydrolysis contains molecules such as polyamines with potential to promote plant growth. Therefore, the aim of the present study was to investigate the biostimulant properties of hydrolyzed biomass of A. platensis. Bioassays were performed to determine auxin-like and cytokinin-like bioactivity of the hydrolysates. In addition, its effect on lettuce seedling growth was investigated and an organic system field trail performed where yield and free polyamine levels in leaves quantified. The hydrolysates had a cytokinin-like effect in the bioassay. Foliar applications promoted the growth of lettuce seedlings with the 4-h reaction hydrolysate (Sph4) being the most effective at promoting growth and increasing the spermine content by 64% in the lettuce leaves. The polyamine concentration was also compared in non-hydrolyzed A. platensis and Sph4. Hydrolysis resulted in a 34% increase in spermine content. It was concluded that Sph4 is a natural plant growth promoter that can be used as a raw material for biostimulants, and spermine could be an active compound and a metabolic indicator of Sph4 bioactivity.

Pearl millet growth and biochemical alterations determined by mycorrhizal inoculation, water availability and atmospheric CO2 concentration

Abstract. Pearl millet (Pennisetum glaucum L.) is an important fodder and is a potential feedstock for fuel ethanol production in dry areas. Our objectives were to assess the effect of elevated CO2 and/or reduced irrigation on biomass production and levels of sugars and proteins in leaves of pearl millet and to test whether mycorrhizal inoculation could modulate the effects of these abiotic factors on growth and metabolism. Results showed that mycorrhizal inoculation and water regime most influenced biomass of shoots and roots; however, their individual effects were dependent on the atmospheric CO2 concentration. At ambient CO2, mycorrhizal inoculation helped to alleviate effects of water deficit on pearl millet without significant decreases in biomass production, which contrasted with the low biomass of mycorrhizal plants under restricted irrigation and elevated CO2. Mycorrhizal inoculation enhanced water content in shoots, whereas reduced irrigation decreased water content in roots. The triple interaction between CO2, arbuscular mycorrhizal fungi (AMF) and water regime significantly affected the total amount of soluble sugars and determined the predominant soluble sugars in leaves. Under optimal irrigation, elevated CO2 increased the proportion of hexoses in pearl millet that was not inoculated with AMF, thus improving the quality of this plant material for bioethanol production. By contrast, elevated CO2 decreased the levels of proteins in leaves, thus limiting the quality of pearl millet as fodder and primary source for cattle feed.