Perdas ocasionadas pelo vírus do mosaico da cana-de-açúcar em parcelas com diferentes níveis iniciais de infecção no material de plantio. I. Perdas na cana-planta

Experiments to determine the yield losses induced by the sugarcane mosaic virus were carried out in Sertãozinho and Lençóis Paulista, São Paulo. The plots were planted with four levels of initial mosaic infection, e.g., 0, 25, 50 and 100%. Virus spread in the experimental plots of the variety CB 46/47 was noticeable, but it was negligible for the variety IAC 50/134. The linear regression of plant-cane yield on increased mosaic infection was significant for the two varieties and two localities. Yield differences between initially healthy and 25% mosaic infected plots were significant for CB 46/47; percentages of yield reductions were 27 and 19%, in Sertãozinho and in Lençóis Paulista, respectively. In the 100% infected plots, the yield reduction was 71%, in the two localities. For the variety IAC 50/134 the only highly significant difference in yield was between plots planted with healthy sets and plots planted with 100% infected sets; percentage wise, the yield difference was 18%, in the two localities. Juice analyses of healthy and diseased canes revealed no differences.Em Sertãozinho e Lençóis Paulista, São Paulo, foram instalados experimentos para determinação das perdas provocadas pelo vírus do mosaico da cana-de-açúcar, em parcelas com 0, 25, 50 e 100% de infecção inicial nos toletes. Durante o ciclo da cultura, foi notada alguma disseminação na variedade CB 46/47 e quase nenhuma na IAC 50/134, as duas variedades ensaiadas. Níveis crescentes de infecção pelo mosaico levaram a reduções crescentes na produção da cana-planta das duas variedades, nas duas localidades. Na var. CB 46/47, verificou-se diferença estatisticamente significativa entre as produções das parcelas sadia e com 25% de infecção inicial; em termos percentuais, a redução foi de 27 e 19% em Sertãozinho e em Lençóis Paulista, respectivamente. Nas parcelas totalmente infectadas, as reduções na produção foram de 71%, nas duas localidades. Na variedade IAC 50/134, somente foram de alta significância as diferenças de produção entre as parcelas inicialmente sadias e as totalmente doentes; percentualmente, estas produziram 18% menos do que aquelas, nas duas localidades. Análises tecnológicas de caldos de canas sadias e caldos de canas doentes não revelaram diferença entre eles

Sugarcane (Saccharum X officinarum): A Reference Study for the Regulation of Genetically Modified Cultivars in Brazil

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars

Combinação de métodos paramétricos e não-paramétricos na análise de estabilidade de cultivares de cana-de-açúcar

A presença e a magnitude da interação genótipo--ambiente são fatores que determinam o desempenho de cultivares nos diversos ambientes de produção. A forma de teste e interpretação dessa interação tem sido muito discutida na literatura agronômica, e vários métodos têm sido propostos. O objetivo deste trabalho foi testar uma combinação de métodos paramétricos e não-paramétricos para avaliação da interação genótipo--ambiente de forma simples e fácil. Foram utilizados os resultados experimentais de três grupos de cultivares de cana-de-açúcar, de acordo com suas características de maturação (precoce, média e tardia), em média de três cortes, em cinco locais da região Oeste do Estado de São Paulo. Os testes utilizados, além de simples, permitiram indicar as melhores cultivares para aquela região e para cada época de colheita, e confirmaram, através de modelos probabilísticos, as recomendações anteriormente realizadas pelos melhoristas

The Brazilian experience of sugarcane ethanol industry

Biomass has gained prominence in the last few years as one of the most important renewable energy sources. In Brazil, a sugarcane ethanol program called ProAlcohol was designed to supply the liquid gasoline substitution and has been running for the last 30 yr. The federal government's establishment of ProAlcohol in 1975 created the grounds for the development of a sugarcane industry that currently is one of the most efficient systems for the conversion of photosynthate into different forms of energy. Improvement of industrial processes along with strong sugarcane breeding programs brought technologies that currently support a cropland of 7 million hectares of sugarcane with an average yield of 75 tons/ha. From the beginning of ProAlcohol to the present time, ethanol yield has grown from 2,500 to around 7,000 l/ha. New technologies for energy production from crushed sugarcane stalk are currently supplying 15% of the electricity needs of the country. Projections show that sugarcane could supply over 30% of Brazil's energy needs by 2020. In this review, we briefly describe some historic facts of the ethanol industry, the role of sugarcane breeding, and the prospects of sugarcane biotechnology

Avaliação qualitativa de plantas de crisântemo (Dendranthema grandiflora Tzvelev) sob condições de estufas com diferentes materiais de cobertura.

No campus de Araras da Universidade Federal de São Carlos foi conduzido um experimento para a comparação da produção de crisântemo, var. Rapture, em três estufas cobertas com diferentes materiais: polietileno de baixa densidade (PEBD, 150g), PVC normal (200g) e PVC tratado com corante azul (200g). Sob o PEBD as plantas apresentaram menor tamanho, apropriado para fins comerciais, mas as inflorescências estavam mais descoloridas pela luz, enquanto que sob PVC azul a altura das plantas foi significativamente maior, ultrapassando o tamanho comercial, mas com menor número de inflorescências descoloridas e maior porcentagem aberta. Sob o PVC normal, o número de inflorescências e a percentagem aberta foi igual à obtida sob PEBD, mas a altura das plantas e a percentagem de flores descoloridas foram intermediárias

Deterioration and fermentability of energy cane juice

ABSTRACT: The main interest in the energy cane is the bioenergy production from the bagasse. The juice obtained after the cane milling may constitute a feedstock for the first-generation ethanol units; however, little attention has been dedicated to this issue. In order to verify the feasibility of the energy cane juice as substrate for ethanol production, the objectives of this research were first to determine the microbiological characteristics and deterioration along the time of the juices from two clones of energy cane (Type I) and second, their fermentability as feedstock for utilization in ethanol distilleries. There was a clear differentiation in the bacterial and yeast development of the sugarcane juices assayed, being much faster in the energy canes than in sugarcane. The storage of juice for 8 hours at 30oC did not cause impact in alcoholic fermentation for any sample analyzed, although a significant bacterial growth was detected in this period. A decrease of approximately seven percentage points in the fermentative efficiency was observed for energy cane juice in relation to sugarcane in a 24-hour fermentation cycle with the baking yeast. Despite the faster deterioration, the present research demonstrated that the energy cane juice has potential to be used as feedstock in ethanol-producing industries. As far as we know, it is the first research to deal with the characteristics of deterioration and fermentability of energy cane juices