Características agronômicas de cultivares de mamona em função do local de cultivo e da época de semeadura no Rio Grande do Sul / Characteristics of castor bean cultivars according to the environmental crop and sowing season in Rio Grande do Sul State, Brazil

A mamona (Ricinus communis L.) é uma planta oleaginosa anual e, ocasionalmente, bienal em regiões tropicais, com ciclo médio de 150 dias para a maioria das cultivares anuais e de 120 a 130 dias para cultivares anuais precoces. O objetivo deste trabalho foi avaliar características agronômicas de cultivares das mamonas 'Al Guarany 2002', 'IAC 80', 'IAC 226' e 'BRS 188 Paraguaçu'em função do ambiente de cultivo e da época de semeadura. As cultivares foram semeadas entre o primeiro e o quinto dia dos meses de novembro e dezembro, na Embrapa Clima Temperado, em Pelotas, Rio Grande do Sul. Cada época teve 12 unidades experimentais em três blocos casualizados. A emergência, a altura de planta e de inserção do primeiro cacho, o período de florescimento e colheita e o ataque de pragas e doenças foram avaliados e analisados com o programa WinStat Versão 2.0. O comportamento entre as cultivares diferiu entre locais de cultivo e época de semeadura. A inserção do cacho foi mais alta, e as florações e colheitas foram mais tardias em plantas da segunda época de semeadura. Danos por pragas e doenças e os descritores morfológicos da planta de mamona apresentaram diferenças entre os locais de cultivo.

Castor bean (Ricinus communis L.) is an oleaginous plant with annual cycle and occasionally biennial cycle in tropical areas, with mean cycle of 150 days for the majority of annual cultivars and 120 to 130 days for annual early cultivars. The objective of this study was to evaluate the agronomic characteristics of castor cultivars according to environmental crop and sowing season. The experiment was conduced at Embrapa Clima Temperado - Pelotas/RS, in two places. The castor cultivars used in this research were 'Al Guarany 2002', 'IAC 80', 'IAC 226' and 'BRS 188 Paraguaçu', which were sown in two sowing times: the first was in early November (between 1st and 5st) and the second was in early December (between 1st and 5st). Each sowing season was constituted of 12 experimental units, distributed in three random blocks. It was evaluated the emergency, plant height and first spike insertion , flowering and harvest time, pest and disease attacks. The WinStat program Version 2.0 was used for data statistical analysis. There was a significant difference among cultivar behaviors between the environmental crops and sowing seasons. The second sowing season provided a larger plant and first spike insertion was higher. It also promoted retardation in the flowering and harvesting time. The differences among cultivars, between the two environmental crops, were clearer in the pest and disease attacks, but also in morphologic characteristics of castor plant.

Avaliação de critério de amostragem de solo para determinação do nitrato residual do tomateiro fertirrigado em ambiente protegido / Evaluation of soil sample criteria for the determination of nitrate residue in tomato plants fertirrigated in an unheated greenhouse

O efeito do posicionamento de amostragem para a quantificação do N-NO3 residual no solo foi determinado após o cultivo do tomateiro fertirrigado. Três experimentos foram conduzidos, em ambiente protegido, com fertirrigação por gotejamento. Em cada experimento, os tratamentos foram arranjados em parcela subdivida, com dez critérios para o manejo da adubação nitrogenada na parcela e posições de amostragem do solo na subparcela. Esses foram arranjados no delineamento experimental de blocos ao acaso. Foi determinado o teor de N-NO3 no solo de amostras retiradas no final do ciclo de cada experimento, em diferentes posições. Em todos os experimentos, o teor de N-NO3 residual no solo foi proporcional à quantidade de N aplicada nos diferentes critérios. Em condições de ambiente protegido e fertilizante nitrogenado fertirrigado por gotejamento, a melhor estratégia de amostragem do solo para a determinação do teor de N-NO3 residual foi obtida pela utilização de amostra composta tomada em posições distanciadas em 10 cm da planta na entre linha e sobre a linha de transplante.

The effect of sample positioning for quantification of residual N-NO3 in soil was determined after cultivating fertirrigated tomato plants. Three experiments were carried out in an unheated greenhouse, using drip fertirrigation. Soil N-NO3 level was determined from samples taken at the end of the cycle of each experiment. In all the experiments, the residual N-NO3 level of the soil was proportional to the amount of N applied in different criteria. Under unheated greenhouse conditions and using nitrogen fertilization by drip fertirrigation, the best soil sampling strategy for residual N-NO3 level determination was obtained by the use of a composite sample taken at a position 10 cm from the plants, between rows, and on the transplant row.

Predição da produção do tomateiro cultivado em ambiente protegido e no campo / Prediction of the tomato plant yield grown in unheated greenhouse and field

A produção dos cinco primeiros cachos de frutos do tomateiro foi utilizada no desenvolvimento de modelo matemático para estimar a produção obtida em nove cachos. Foram conduzidos seis experimentos, sendo quatro em ambiente protegido (A, B, C e D) e dois no campo (E e F), na Universidade Federal de Viçosa. Todos os experimentos constaram de dez tratamentos com doses diferenciadas de N que variaram de 0 a 1.953,7 kg./ha-1. Os dados de produção total acumulada de frutos até o 1°, 2°, 3°, 4° e 5° cacho dos experimentos C e E foram submetidos à análise de variância e modelos de regressão foram ajustados em relação à produção acumulada até o 9° cacho. A validade dos modelos propostos foi verificada com base na correlação (r) entre os dados observados e estimados pelo modelo e pela análise do quadrado médio dos desvios (QMD) e seus componentes aditivos. Os modelos propostos, baseados na produção acumulada até o 5° cacho, foram precisos em estimar a produção total de frutos acumulada no tomateiro com 9 cachos em ambiente protegido e no campo. Os modelos devem ser comparados e validados com dados de outros estudos. A análise do quadrado médio dos desvios (QMD) e seus componentes são úteis para verificar a validade de modelos de regressão através da quantificação dos desvios do modelo e identificação das causas desses desvios.

The tomato plant yield of the first five clusters was used in the development of mathematical model to estimate yield obtained in nine trusses. Six experiments were carried out, being four in unheated greenhouse (A, B, C and D) and two in the field (E and F), in the Federal University of Viçosa. All the experiments consisted of ten treatments with differentiated N rates that ranged from 0 to 1,953.7 kg./ha-1. The data up to the 1st, 2nd, 3rd, 4th and 5th trusses accumulated total yield of the experiments C and E were submitted to the analysis of variance and regression models and were adjusted to 9th trusses accumulated yield. The proposed models validity was based on the correlation (r) among the observed and estimated data by the model and by the medium square deviations (MSD) analysis and its additive components. The proposed models, based on the yield accumulated until 5th trusses were precise in estimate the total fruits yield accumulated in the tomato plant with 9 trusses in unheated greenhouse and field. The models should be compared and validated with data of other studies. The medium square deviations (MSD) analysis and its components are useful to verify the regression models validity through the model deviations quantification and identication causes of those deviations.

Caracteres morfológicos de soja e braquiária consorciadas sob subdoses de fluazifop-p-butil / Morphologic characters of soybean and Brachiaria intercropped under reduced rates of fluazifop-p-butil

A degradação das pastagens é um dos maiores problemas da pecuária, afetando diretamente a sustentabilidade do setor. Como alternativas de recuperação, tem sido proposta a utilização de culturas anuais em consórcio com forrageiras. No entanto, para a viabilização do consórcio, é necessário o manejo adequado da forrageira minimizando a competição com a cultura. Objetivou-se, neste trabalho, avaliar os efeitos da aplicação do fluazifop-p-butil em caracteres morfológicos de Brachiaria brizantha e soja, cultivadas em consórcio. O experimento foi realizado em Coimbra-MG. Foram avaliadas seis doses de fluazifop-p-butil (0, 18, 36, 54, 72 e 90g ha-1) aplicadas em duas épocas (21 e 28 dias após a emergência da soja - DAE) e 2 testemunhas (soja e braquiária em monocultivo e capinadas). Não foi verificada interação entre doses e épocas de aplicação. Todavia, as doses 0, 18 e 36g ha-1, influenciaram negativamente o índice de área foliar (IAF), a biomassa seca das folhas, da haste + pecíolos e das vagens das plantas de soja. O IAF, a biomassa seca das folhas (BSF), o número, o comprimento e a biomassa seca dos colmos (BSC) da B. brizantha, foram afetados pelas doses e épocas de aplicação. A aplicação aos 28 DAE foi mais prejudicial à B. brizantha do que quando realizada aos 21 DAE. Na avaliação efetuada aos 53 DAE, para as variáveis BSF, BSC e IAF, as doses 0, 18 e 36g ha-1, aplicadas aos 21 DAE, e as doses 0 e 18g ha-1, aplicadas aos 28 DAE, não diferiram da B. brizantha em monocultivo. Aos 78 DAE, somente a dose 0 não diferiu da B. brizantha em monocultivo nas duas épocas de aplicação. Ao utilizar 36g ha-1 de fluazifop-p-butil, houve o favorecimento da B. brizantha em relação à soja. Por outro lado, a dose de 54g ha-1 de fluazifop-p-butil privilegiou a soja em detrimento da B. brizantha. Nas condições em que foi conduzido o ensaio a faixa ideal do herbicida, visando o consórcio, foi de 40g ha-1 de fluazifop-p-butil.

Multivariate analysis of combining ability for soybean resistance to Cercospora sojina Hara

Seven soybean cultivars (Bossier, Cristalina, Davis, Kent, Lincoln, Paraná and Uberaba), with different levels of resistance to Cercospora sojina, race 04, were crossed according to a diallel design, with no reciprocals, to determine the general and the specific combining abilities for the resistance. The evaluations of the reaction to the disease were performed 20 days after the inoculation of the fungus on the most infected leaflet of the plant, in the parents and in the F1 hybrids. To quantify the resistance, the following characteristics were evaluated: infection degree (ID); number of lesions per leaflet (NLL); lesion mean diameter (LMD); lesioned leaf area (LLA); percentage of lesioned leaf area (PLLA); number of lesions per square centimeter (NLC) and disease index (DI). The relative importance of each characteristic was evaluated by the canonical variables analysis and the LLA and NLL characteristics were eliminated from the multivariate function. With the remaining five characteristics, a multivariate index was created using the first canonical vector, which was submitted to the diallel analysis, according to Griffings fixed model, method 2. The most important characters to discriminate resistant from susceptible soybean plants to C. sojina were: ID, LMD, NLC, DI and PLLA. Cristalina, Davis and Uberaba cultivars are the best ones among those tested that can be recommended as parents in soybean breeding programs seeking resistance to Cercospora sojina. The additive, dominant and epistatic genetic effects were important for the expression of the resistance, although the additive genetic effect was the most important component.

RAPD and SCAR markers linked to resistance to frogeye leaf spot in soybean

The soybean (Glycine max (L.) Merrill) frogeye leaf spot is caused by the fungus Cercospora sojina Hara and is a widespread disease in Brazil and other countries, causing severe losses in grain yield and also affecting seed quality. The availability of DNA markers linked to genes for resistance to this disease would accelerate breeding programs, particularly when other traits are also being evaluated. Bulked segregant analysis was applied to 3 F2 populations derived from crosses between the resistant cultivars Parana, Cristalina and Uberaba, and the susceptible cultivar Bossier. In the cross 'Parana' x 'Bossier', 2 RAPD markers were identified, CSOPA1800C and CSOPA21,250C, located at 4.4 1.8 centiMorgans (cM) and 3.4 1.7 cM respectively from the resistance locus. DNA fragments of similar molecular weight were observed in the population derived from the cross 'Cristalina' x 'Bossier' at 2.3 1.2 and 4.7 1.5 cM from the resistance locus, respectively. In the offspring of the cross 'Uberaba' x 'Bossier', a DNA fragment corresponding to marker CSOPA1800C was detected at 5.6 2.1 cM from the resistance locus. Although marker CSOPA21,250C was not observed in this population, an additional marker was detected (CSOUB11,100C) at 6.7 2.2 cM from the resistance locus. The 1,250 bp fragment of CSOPA21,250C was cloned and converted into a SCAR marker, which amplified a single fragment whose size corresponded to the cloned segment of the crosses involving cultivars Cristalina and Parana. Markers CSOPA1800C, CSOPA21,250C and CSOUB11,100C were mapped to soybean linkage group J with the aid of known SSRs linked to the Rcs3 locus, indicating that the RAPD and SCAR markers identified in our research also tag this resistance gene

Dupla difusäo radial na análise genética das lipoxigenases L1 e L2 em soja / Double gel immunodiffusion in the genetic analysis of lipoxygenases L1 and L2 from soybeans

In the effort to genetically manipulate soybean seeds aiming to improve flavor quality toward human consuption, lipoxygenase null alleles are being transferred to a brazilian commercial variety. Immunochemical approach has been taken to perform analysus of hundred of seeds derived from the breeding program. For that reason lipoxygenases L1 and L2 were puridied to hemogeneity by gel filtration and affinity chromatography. Policlonal antibodies were prepared in rabbits and purified further by affinity chromatogrphy. By using the purified anti-L1 and anti-L2 an Ouchterlony double immunodifusion method has been developed in our lab to detect the presence/absence of the isozymes simultaneously in soybean seeds. The method proved to be highly specific and efficient enought to perform single non destructive seed analysis