Emergência de Rottboellia exaltata influenciada pela profundidade de semeadura, quantidade de palha de cana sobre o solo e aplicação de herbicidas residuais

Mechanical sugarcane harvest without burning and continuous straw on the soil surface may affect the Rottboellia exaltata infestation dynamics in sugarcane fields. Three greenhouse experiments were conducted with the aim of studying the effects of sowing depth (0, 2.5, 5, 7.5, and 10 cm), amount of sugarcane straw on the soil surface (0, 5, 10, and 15 ton ha-1), and residual herbicide (clomazone, flumioxazin, imazapyr, isoxaflutole, and s-metolachlor) on the emergence of Rottboellia exaltata. For each experiment, a completely randomized design with four replicates was applied. The combination of mulch on soil surface (especially with larger amounts of straw) with deeper sowing depths provides less emergence and mass accumulation of R. exaltata. In bare soil, the sowing depth did not affect the weed dynamics. Clomazone and imazapyr were effective herbicides controlling R. exaltata regardless of the amount of straw on the soil surface. Flumioxazin was also effective in controlling R. exaltata but only under bare soil conditions. Even with 60 mm of accumulated rainfall over the 4 day period after application, the amount of flumioxazin leached to the soil was not enough to ensure the same control observed when applying the herbicide on bare soil.

Characterization and impact of the sugarcane borer on sugarcane yield and quality

The sugarcane borer, Diatraea saccharalis (F.) (Lepidoptera: Crambidae), is a key pest of sugarcane (Saccharum spp.). While damage caused by this pest has increased in the past 20 yr, studies investigating the insect-plant interactions are still lacking. Moreover, there is no information about the consequences of borer damage on the parameters of sugar quality. Therefore, two field experiments were performed during the 2010 and 2011 growing seasons in Brazil to compare the raw material and sugar quality of SP80-3280 sugarcane plants with and without the sugarcane borer. Plants were protected within screen cages and infested weekly during the 2010 and 2011 seasons, using egg masses starting at the second and third internode stage. At harvest, 25.77 and 19.01% of the internodes were bored by larvae (infestation intensity, II) in the first and second seasons, respectively. There was no correlation between the borer gallery total volume and II. The fiber content significantly increased with increasing II. The stalk biometric parameters, such as length, diameter, and yield, were not correlated with II. The sucrose yield significantly decreased with increasing II. Consequently, sugar yield losses were estimated at 8.83 and 19.80% per 1% bored internode for the first and second seasons, respectively. The concentration of phenolic compounds increased, and unclarified juice color quality decreased, with increasing II. Significant differences were detected in the quality of the sugar. These results should be confirmed for other sugarcane cultivars and incorporated into an economic injury level to enhance decision-making strategies for borer management. © 2013 by the American Society of Agronomy, 5585 Guilford Road, Madison, WI 53711. All rights reserved.

Greenhouse gas mitigation potential from green harvested sugarcane scenarios in São Paulo State, Brazil

Brazil is a major sugarcane producer and São Paulo State cultivates 5.5 million hectares, close to 50% of Brazil's sugarcane area. The rapid increase in production has brought into question the sustainability of biofuels, especially considering the greenhouse gas (GHG) emissions associated to the agricultural sector. Despite the significant progress towards the green harvest practices, 1.67 million hectares were still burned in São Paulo State during the 2011 harvest season. Here an emissions inventory for the life cycle of sugarcane agricultural production is estimated using IPCC methodologies, according to the agriculture survey data and remote sensing database. Our hypothesis is that 1.67 million hectares shall be converted from burned to green harvest scenarios up to years 2021 (rate 1), 2014 (rate 2) or 2029 (rate 3). Those conversions would represent a significant GHG mitigation, ranging from 50.5 to 70.9 megatons of carbon dioxide equivalent (Mt CO2eq) up to 2050, depending on the conversion rate and the green harvest systems adopted: conventional (scenario S1) or conservationist management (scenario S2). We show that a green harvest scenario where crop rotation and reduced soil tillage are practiced has a higher mitigation potential (70.9 Mt CO2eq), which is already practiced in some of the sugarcane areas. Here we support the decision to not just stop burning prior to harvest, but also to consider other better practices in sugarcane areas to have a more sustainable sugarcane based ethanol production in the most dense cultivated sugarcane region in Brazil. © 2013 Elsevier Ltd. All rights reserved.

Sugarcane vinasse: Environmental implications of its use

The inadequate and indiscriminate disposal of sugarcane vinasse in soils and water bodies has received much attention since decades ago, due to environmental problems associated to this practice. Vinasse is the final by-product of the biomass distillation, mainly for the production of ethanol, from sugar crops (beet and sugarcane), starch crops (corn, wheat, rice, and cassava), or cellulosic material (harvesting crop residues, sugarcane bagasse, and wood). Because of the large quantities of vinasse produced, alternative treatments and uses have been developed, such as recycling of vinasse in fermentation, fertirrigation, concentration by evaporation, and yeast and energy production. This review was aimed at examining the available data on the subject as a contribution to update the information on sugarcane vinasse, from its characteristics and chemical composition to alternatives uses in Brazil: fertirrigation, concentration by evaporation, energy production; the effects on soil physical, chemical and biological properties; its influence on seed germination, its use as biostimulant and environmental contaminant. The low pH, electric conductivity, and chemical elements present in sugarcane vinasse may cause changes in the chemical and physical-chemical properties of soils, rivers, and lakes with frequent discharges over a long period of time, and also have adverse effects on agricultural soils and biota in general. Thus, new studies and green methods need to be developed aiming at sugarcane vinasse recycling and disposal. © 2013 Elsevier Ltd. All rights reserved.

Avaliação termodinâmica, termoeconômica e econômica da integração de sistemas de gaseificação da biomassa em uma usina sucroalcooleira

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Consumo de combustível de duas colhedoras de cana-de-açúcar em função da velocidade e rotação de motor

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Balanço de gases de efeito estufa em áreas de cana-de-açúcar sob diferentes cenários de manejo, considerando-se mitigações

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Manejo da soqueira de cana-de-açúcar submetida à queima acidental da palhada remanescente da colheita mecanizada

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Tempo de decomposição de palha e contribuição na nutrição da cana-de- açúcar em função da aplicação de vinhaça e gesso

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Avaliação do controle de azevém (Lolium multiflorum) nas condições de cana crua em Louisiana/EUA e dinâmica dos herbicidas na palha

Pós-graduação em Agronomia (Agricultura) - FCA

Nutrição potássica em soqueiras de cana-de-açúcar com colheita sem despalha a fogo

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Nitrogênio em soqueiras de cana-de-açúcar cultivada em sistema conservacionista

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Sistemas de manejo conservacionista do solo para cultivares de amendoim em sucessão à cana crua e pastagens

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Produção e eficiência de isolados de Metarhizium anisopliae (Metsch.) Sorok. no controle da cigarrinha-das-raízes da cana-de-açúcar, Mahanarva fimbriolata (Stal, 1854) (Hemiptera: Cercopidae)

Pós-graduação em Agronomia (Proteção de Plantas) - FCA

Harvest managements and cultural practices in sugarcane

The presence of trash from the mechanical harvest of green cane on sugarcane plantations promotes changes in the agricultural management, for example, in the mechanical cultural practices of ratoon cane in-between the rows and nitrogen (N) fertilization. The goal of this study was to evaluate the performance of sugarcane in different harvest systems, associated to the mechanical cultural practices in interrows and N rates. The study was carried out on a sugarcane plantation in Sales Oliveira, São Paulo, Brazil, with the sugarcane variety SP81-3250, on soil classified as Acrudox, in a randomized block design with split-split plots and four replications. The main treatments consisted of harvest systems (harvesting green cane or burnt cane), the secondary treatment consisted of the mechanical cultural practices in the interrows and the tertiary treatments were N rates (0, 30, 60, 90, 120 and 160 kg ha-1), using ammonium nitrate (33 % N) as N source. The harvest systems did not differ in sugarcane yield (tons of cane per hectare - TCH), but in burnt cane, the pol percent and total sugar recovery (TSR) were higher. This could be explained by the higher quantity of plant impurities in the harvested raw material in the system without burning, which reduces the processing quality. Mechanical cultural practices in the interrows after harvest had no effect on cane yield and sugar quality, indicating that this operation can be omitted in areas with mechanical harvesting. The application of N fertilizer at rates of 88 and 144 kg ha-1 N, respectively, increased stalk height and TCH quadratically to the highest values for these variables. For the sugar yield per hectare (in pol %), N fertilization induced a linear increase.