Doses, fontes e modos de aplicação de zinco na cultura da cana-de-açúcar

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impactos de sistemas de cultivo, extrato húmico e adubos orgânico e mineral sobre alguns atributos físicos e químicos de um latossolo, cultivado com cana-de-açúcar

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

Sugarcane tolerance to ratoon eradication with glyphosate determined by physiological responses

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Potencial produtivo da cana-de-açúcar sob irrigação por gotejamento em função de variedades e ciclos

This study aimed to evaluate the yield potential of different varieties of sugarcane under drip irrigation in two growth cycles. A trial was set up in October 2006 at Jaú region (São Paulo state, Brazil), in an experimental field with a eutrophic Ultisol. The experiment was conducted in randomized complete blocks with factorial treatment structure 8 x 2, constituted by eight sugarcane varieties and two crop cycles, with six replicates. Stalk productivity (TCH), sugar productivity (TPH), juice quality traits and water use efficiency in relation to stalk productivity were evaluated in each crop cycle. It was observed that varieties of sugarcane respond differently to full irrigation, and this response is influenced by climatic conditions of the agricultural year. In this study, only the first evaluation cycle (plant cane) was decisive to differentiate the performance among the varieties. The varieties IAC91-1099, IACSP96-3060, RB855536, RB867515 and SP85-1115 showed higher agro-industrial yield potential and less consumption of water and can be recommended for the management of production under drip irrigation.

Sugarcane productivity correlated with physical-chemical attributes to create soil management zone

The socioeconomic importance of sugar cane in Brazil is unquestionable because it is the raw material for the production of ethanol and sugar. The accurate spatial intervention in the management of the crop, resulting zones of soil management, increases productivity as well as its agricultural yields. The spatial and Person's correlations between sugarcane attributes and physico-chemical attributes of a Typic Tropustalf were studied in the growing season of 2009, in Suzanápolis, State of São Paulo, Brazil (20°28'10'' S lat.; 50°49'20'' W long.), in order to obtain the one that best correlates with agricultural productivity. Thus, the geostatistical grid with 120 sampling points was installed to soil and data collection in a plot of 14.6 ha with second crop sugarcane. Due to their substantial and excellent linear and spatial correlations with the productivity of the sugarcane, the population of plants and the organic matter content of the soil, by evidencing substantial correlations, linear and spatial, with the productivity of sugarcane, were indicators of management zones strongly attached to such productivity.

Inter-relações da produtividade de cana soca com a resistência à penetração, umidade e matéria orgânica do solo

The sugarcane crop plays an important role on Brazilian economy,, especially in the aspect related to alternative energy sources. Yield of ratoon cane (2nd cycle) was evaluated in relation to resistance to penetration, gravimetric moisture and organic matter in a Typic Tropustalf, in the municipality of Suzanápolis (SP), 20º28'10'' S and 50º49'20'' W, in the Brazilian cerrado, in 2009. The main purpose was to select, among the attributes surveyed, the one with the highest linear and spatial correlations that explains the variability of sugar cane yield. A geostatistical grid was installed in order to collect data from the soil as well from the plant, with 120 sampling points in an area of 14.53 ha. Organic matter correlated linearly and negatively with penetration resistance, indicating that the soil management practices that aim its increase in the soil profile can improve soil physical conditions, and consequently, the development and yield of sugarcane. Both gravimetric moisture (UG) and content of soil organic matter (OM) correlated directly, linearly (UG2 and MO1) and spatially (UG1 and MO1) with sugarcane yield, proving to be the best attributes, among the evaluated ones, to estimate and increase the sugarcane yield.

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.

Crescimento e produtividade de cana-de-açúcar em função da disponibilidade hídrica dos Tabuleiros Costeiros de Alagoas

The aim of this study was to evaluate the interaction among meteorological variables and yield components of six sugarcane varieties and to establish appropriate varietal management at the Coastal Tablelands of the Alagoas State (Brazil). The sugarcane planting was carried out in September 2005, and three cane harvests were made in November 2006, 2007 and 2008. The experimental design was in randomized block with six treatments consisting of the varieties RB863129, RB867515, RB92579, RB93509, RB931003 and RB951541, with four replications. The growth variables evaluated were number and length of stalks, leaf area index, and productivity of stalks and sugar. On average, the crop water balance showed water deficit of 869 mm between September and March and excess of 837 mm from April to August. The irregularity of rainfall in the Coastal Tablelands promoted differential responses in the development and productivity of varieties of sugarcane. Varieties RB93509 and RB931003 are considered options for the varietal management in this region.

Photosynthetic capacity and water use efficiency in sugarcane genotypes subject to water deficit during early growth phase

The objective of this study was to compare the gas exchange, photosynthetic capacity and water potential of sugarcane genotypes cultivated under water deficit conditions imposed during the initial growth phase. Experiments were performed in a greenhouse using two sugarcane genotypes namely: HoCP93-776 (drought susceptible) and TCP02-4587 (drought tolerant). Sixty days after planting, two different water treatments were applied (i.e., with or without water deficit). At 0,30 and 60 days after the treatment, gas exchange variables were evaluated for their relationship with water use, intrinsic instantaneous water use efficiency and instantaneous carboxylation efficiency. The SPAD index, photosynthetic pigments, water potential and relative water content in the leaves were also analyzed. The genotype HoCP93-776 was more sensitive to drought treatment as indicated by the significantly lower values of SPAD index, photosynthetic pigments, water potential (Ψw) and relative water content (RWC) variables. The genotype TCP02-4587 had higher water potential, stomatal control efficiency, water use efficiency (WUE), intrinsic instantaneous water use efficiency (WUEintr), instantaneous carboxylation efficiency and photosynthetic capacity. The highest air vapor pressure deficit during the drought conditions could be due to the stomatal closing in the HoCP93-776, which contributed to its lower photosynthetic capacity.

Modalities for soil preparation and gypsum application in ultisol: stem productivity of sugarcane

O trabalho foi conduzido em área de expansão de cana-de-açúcar da Usina Vale do Paraná, no município de Suzanápolis - SP, na região do noroeste paulista. Foi utilizada a variedade de cana RB92-5345, espaçamento de 1,5 m entre linhas, em ARGISSOLO VERMELHO. O trabalho objetivou avaliar a produtividade em cana-planta e 1ª cana-soca e alguns atributos químicos de solo, em função dos métodos de preparo do solo e aplicação ou não de gesso. O delineamento experimental utilizado foi o de blocos ao acaso, com seis tratamentos, fatorial 3x2, e seis repetições. Os tratamentos principais foram preparos de solo com três equipamentos: arado de aivecas, escarificador e grade pesada, e dois tratamentos secundários com aplicação de 1 t ha-1 de gesso e sem gesso. Após cada colheita da cana, o solo foi caracterizado quanto aos indicadores de fertilidade nas camadas de 0,0-0,15; 0,15-0,30 e 0,30-0,45 m. As diferenças dos atributos químicos do solo, devido aos métodos de preparo ocorridas na cana-planta, não perduraram até a colheita da 1ª cana-soca e também não influenciaram na produtividade da cultura. A gessagem proporcionou maiores valores de ATR e produtividade de TCH, para cana-planta e 1ª cana-soca, respectivamente, confirmando a hipótese inicial.

Alterações morfoanatômicas foliares da cana-de-açúcar na fase de estabelecimento em condições de matocompetição

Aiming at the assessment of the production parameters and leaf tissues morph anatomical possible changes of the sugar cane RB 86 7515 variety in its establishment phase in the conditions of weed competition, a study over vases has been accomplished in the city of Dracena, São Paulo State, from April to June, 2010, at Universidade Estadual Paulista Júlio de Mesquita Filho. The species Brachiaria brizantha e Brachiaria decumbens, which are regarded as invaders, were used. It was also used the Completely Randomized Design with seven treatments and five repetitions, totalizing 35 lots or vases. The treatments ranged according to the number of Brachiaria brizantha and Brachiaria decumbens seeds, as it follows: T1 - no occurrence of weed competition; T2 - low occurrence of weed competition with Brachiaria brizantha; T3 - medium occurrence of weed competition with Brachiaria brizantha; T4 - high occurrence of weed competition with Brachiaria brizantha; T5 - low occurrence of weed competition with Brachiaria decumbens; T6 - medium occurrence of weed competition with Brachiaria decumbens, and T7 - high occurrence of weed competition with Brachiaria decumbens. There was an evaluation over the following issues after 60 days of the sugar cane plantation and the invading plants: the weight of the total dry matter of the plants, the thickness of the upper surface epidermis or adaxial, the thickness of the lower surface or abaxial, the thickness of the mesophill, the thickness of the limbo, the diameter of the xylematic vessels and the diameter of the phloem vessels. The weed competition of the species Brachiaria brizantha e Brachiaria decumbens, which are considered as invaders, provoked some reduction of the morph anatomical characteristics and of the sugar cane production. In general, the Brachiaria decumbens was the species which mostly influenced the leaf thickness of the sugar cane in negative aspects.

Adaptabilidade e estabilidade de clones de cana-de-açúcar

The objective of this study was to identify clones of sugarcane with good stability and adaptability in the State of São Paulo, Brazil, and also identifying locations most representative for selection and experimentation. Ten clones and two commercial checks of medium-late maturation were evaluated in the first-ratoon of experiments harvested in August 2009, using bissegmented regression and AMMI (Additive Main Effects and Multiplicative Interaction Analysis) methods. The results of two methods were compared and they evidenced that the clones RB975201, RB975157, RB975932, RB975242 and RB975162 are the most promising, showing higher production when compared to the checks, higher stability observed in one or both statistical methods and broader or more specific adaptability. The environment Tarumã presented higher stability and capacity to discriminate genotypes, allowing an ordering more reliable as compared to the overall mean of the environments tested.

Nutrição potássica em soqueira de cana-de-açúcar colhida sem queima

Pós-graduação em Agronomia (Ciência do Solo) - FCAV

Espacialização do banco de sementes de plantas daninhas sob diferentes manejos de cana-de-açúcar em Rio Brilhante, Mato Grosso do Sul

The State of Mato Grosso do Sul is in full growth of this sector, thus the concern about harvesting systems are being studied, and these systems may influence the weed community interference of weeds in the cane sugar. The integrated management tool attached to geostatistics is to avoid productivity losses due to weed interference. The objective of this work was to study the spatial variability of the seed bank of weeds depending on the system for collecting cane sugar (raw and burning). The experiment was conducted in the area of commercial cultivation of the plant ETH Bioenergy S/A Eldorado Unity. Soil samples were taken with auger layer from 0.00 to 0.40 m depth in both cropping systems. The experimental plot was composed by a mesh consisting of 50 points georeferenced with irregular distances. Soil samples were taken to the greenhouse for germination. The number of weed species was analyzed using descriptive statistics and geostatistical techniques. The seeds of B. pilosa, dicots, bitter grass, nutsedge, dayflower monocots and spatial dependence of the seed bank in the collection system with burning of cane sugar. For the system of harvest only the raw sedge species present spatial dependence of distribution in the seed bank. In the harvest green cane enable the mapping of these species through the kriging maps produced, spot applications of herbicides in integrated management of Cyperus rotundus.

Selfing rate estimation in sugarcane under unfavorable natural conditions of crossing by using microsatellite markers

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