Maximiliano Salles Scarpari

Sugarcane maturity estimation through edaphic-climatic parameters

Sugarcane (Saccharum officinarum L.) grows under different weather conditions directly affecting crop maturation. Raw material quality predicting models are important tools in sugarcane crop management; the goal of these models is to provide productivity estimates during harvesting, increasing the efficiency of strategical and administrative decisions. The objective of this work was developing a model to predict Total Recoverable Sugars (TRS) during harvesting, using data related to production factors such as soil water storage and negative degree-days. The database of a sugar mill for the crop seasons 1999/2000, 2000/2001 and 2001/2002 was analyzed, and statistical models were tested to estimate raw material. The maturity model for a one-year old sugarcane proved to be significant, with a coefficient of determination (R2) of 0.7049*. No differences were detected between measured and estimated data in the simulation (P < 0.05).

Physiological model to estimate the maturity of sugarcane.

Sugarcane (Saccharum spp.) grows in different weather and management conditions which directly affect crop maturation. These conditions lead to the necessity of quantifying crop response to different stimuli for planning purposes. Forecast models for the quality of raw material are important tools in sugarcane farming, especially the forecast curve of sucrose accumulation in shoots. The goal of these models is to supply yield estimates during the crop cycle, aiming to characterize alternatives and to increase the efficacy for management and strategic decisions. The objective of this project was to develop empiric models capable of obtaining estimates of total recoverable sugar (TRS), for the varieties RB72454, SP81-3250 and SP80-1842 during the crop cycle, using reference data as the production factors. Sugarcane harvest results obtained in Piracicaba, State of Sao Paulo, Brazil were analyzed using the following parameters: maturation, stand age, type of soil, variety, flowering and management for the crops in the years 1998/99, 1999/00, 2000/01, 2001/02 and 2002/03. Models developed for these years were used to estimate TRS from the 2003/04 cropping season. All the forecast models for ratoon crops were significant indicating that they are an excellent tool to optimize agricultural planning.

Residual biomass potential of commercial and pre-commercial sugarcane cultivars

Sugarcane (Saccharum spp.) is an efficient and sustainable alternative for energy generation compared to non-renewable sources. Currently, during the mechanized harvest process, the straw left in the field can be used in part for the second generation ethanol and increasing the electric energy production. Thus, this study aimed to provide information on the potential for residual biomass cultivars of sugarcane cropping system. This study provides the following information: yield of straw, depending on the calculated leaf area index and the number of tillers per linear meter; primary energy production of several sugarcane genotypes; contribution of dry tops and leaves; biomass yield; and evaluation of fiber, cellulose, hemicellulose and lignin. Preliminary results obtained by researchers of the State of Sao Paulo, Brazil, and reCviews related studies are presented. The results suggest that the production of sugarcane straw content varies according to the cultivars; the greater mass of sugarcane straw is in the top leaves and that the potential for the crude energy production of sugarcane per area unit can be increased using fiber-rich species or species that produce more straw. The straw indexes was shown to be a good indicator and allow the estimation of straw volumes generated in a sugarcane crop. The cellulose, hemicellulose and lignin composition in sugarcane is distinct among varieties. Therefore, it is possible to develop distinct biomass materials for energy production and for the development of sugarcane mills using biochemical processes and thermal routes.

Variação espaço-temporal do índice de área foliar e brix em cana-de-açúcar

The goals of this work were to study the spatial-temporal variation of leaf area index (LAI) and soluble solids (Brix) in sugarcane cultived in Piracicaba, Sao Paulo State, in the years of 2003 and 2004. Geoestatistic methodology was used aiming improvement in the simulation of solar radiation interception, and specially adjustment of extinction coefficient. During growth cycle larger values of leaf area index were verified in variety SP 80-3280 than in RB 85 5156. Those values ranged from 6.41 to 4.27 respectively, and were measured in 1/14/2004, with large spatial variation. Higher values for LAI and smaller values for Brix were also observed under high water available, indicating a delay in maturation. The only Brix measurement performed in the varieties SP 80-3280 and RB 85 5156 on 4/29/2004 indicated average values of 12.86 and 17.06 respectively, demonstrating the precocity of RB 85 5156. The use of daily variable values of the extinction coefficient is recommended, improving the simulation of solar radiation interception, minimizing mistakes estimating the productivity when different sugarcane varieties were analyzed.