Cana-de-açúcar: crescimento, maturação e distribuição de energia

Abstract

The search for the use of renewable fuels, such as ethanol, and due to international market demand for sugar, increases in the of sugarcane production leading to expansion in the area planted with sugar cane. In the Center-South of Brazil, areas were expansions in northern Paraná State, southern Mato Grosso do Sul State, west of Sao Paulo State. These regions are, in general, sandy soils and uneven distribution of rainfall and can promote water stress in plants during periods called veranículos . To study the behavior of sugarcane in its growth, technologic parameters and distribution of energy in products of photosynthesis. The tests were set up with a completely randomized design with two treatments, 100% replacement of evapotranspiration and 20% evapotranspiration, 10 replicates using a total of 20 plots. Each plot consisted of a vase with a plant matrix. The seedlings were derived from an experimental plantation of sugar cane at the University, with an average age of 10 months. The cultivar used was the RB 86 7515. Was executed roguing for selection of seedlings before and after the thermal treatment in water at 52 °C for 30 minutes. The aim of this study was to evaluate the responses biometric technology and energy in the culture of sugar cane in irrigated and water stressed, in order to determine the distribution of the absorbed energy between simple sugars (sucrose, glucose and fructose) and fiber. During the development of plant sugarcane, the new shoots that emerged (tillers) were chopped, with the goal of conducting only the mother plant in the pot. The seedlings of sugar cane developed in this controlled environment for 4 months, after this period the plants were collected whole, and sent for analysis. The replenishing water was based on the ability of field soil collected, where 12 kg of soil was added 1.5 liters of water to field capacity, namely: Replacement of the vessels 20% = weight of the vessel control field capacity (weight control vessel one day after) X 0.2 X Kc. Replacement vessel weight = 100% control of the vessel at field capacity - weight control vessel one day after X 1.0 X Kc. The following crop coefficients (Kc) were used: 0.50 (plants 60 days in the chamber, comprising the period from planting to 25% coverage) and 0.88 (after 60 days the plants in the chamber, comprising the period of 25 to 50% coverage). The biometric analysis, technological, and calorimetric were performed. With water stress, a reduction in the sugarcane s mass and in all analyzed components (TRS, Pol, RS Brix and fiber). The reductions were not proportional because concentrations of components were very variable. The molecules that were intended to produce fibers were retained in the cytoplasm ready for conversion into energy. The total bioenergy system was reduced in the same proportion of biomass.