Spatio-temporal variability of sugarcane yield efficiency in the state of São Paulo, Brazil

The objective of this work was to assess the spatial and temporal variability of sugarcane yield efficiency and yield gap in the state of São Paulo, Brazil, throughout 16 growing seasons, considering climate and soil as main effects, and socioeconomic factors as complementary. An empirical model was used to assess potential and attainable yields, using climate data series from 37 weather stations. Soil effects were analyzed using the concept of production environments associated with a soil aptitude map for sugarcane. Crop yield efficiency increased from 0.42 to 0.58 in the analyzed period (1990/1991 to 2005/2006 crop seasons), and yield gap consequently decreased from 58 to 42%. Climatic factors explained 43% of the variability of sugarcane yield efficiency, in the following order of importance: solar radiation, water deficit, maximum air temperature, precipitation, and minimum air temperature. Soil explained 15% of the variability, considering the average of all seasons. There was a change in the correlation pattern of climate and soil with yield efficiency after the 2001/2002 season, probably due to the crop expansion to the west of the state during the subsequent period. Socioeconomic, biotic and crop management factors together explain 42% of sugarcane yield efficiency in the state of São Paulo.

Influência de silicato e calcário na nutrição, produtividade e qualidade da batata sob deficiência hídrica

A aplicação de silicato de Ca e Mg pode diminuir a acidez do solo e aumentar a disponibilidade de Ca, Mg, P e Si às plantas. O Si, mesmo não sendo essencial do ponto de vista fisiológico, traz inúmeros benefícios para o crescimento e o desenvolvimento vegetal, especialmente sob estresse. Este trabalho teve por objetivo avaliar a nutrição, a produtividade e a qualidade de tubérculos e batata cultivada em solo corrigido com calcário ou silicato sob dois níveis de umidade no solo. Os tratamentos foram constituídos pela aplicação de calcário dolomítico ou silicato de Ca e Mg, visando elevar a saturação por bases do solo a 60 %, e por duas tensões de água no solo: 0,020 MPa (sem deficiência hídrica) e 0,050 MPa (com deficiência hídrica). O experimento foi conduzido em casa de vegetação, em vasos contendo 50 kg dm-3 de Latossolo Vermelho de textura média. O delineamento foi inteiramente ao acaso em fatorial 2 x 2, com oito repetições. A deficiência hídrica teve pouca influência na nutrição da batateira, porém reduziu a produção de tubérculos comercializáveis. O silicato de Ca e Mg proporcionou os mesmos níveis de correção do solo e de fornecimento desses nutrientes que o calcário dolomítico, além de maior disponibilidade de P e Si no solo e maior absorção desses elementos pelas plantas de batata, podendo ser utilizado em substituição ao calcário. O fornecimento de Si à cultura da batata, mediante a aplicação de silicato, proporcionou maior altura de plantas, menor acamamento das hastes e maior produção de tubérculos comercializáveis.

Frutificação, características físicas de frutos e produtividade em cultivares e seleções de pessegueiro em Vista Alegre do Alto-SP

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

Crescimento e produtividade de variedades de cana-de-açúcar em função da disponibilidade hídrica nos tabuleiros costeiros de Alagoas

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Crescimento, produtividade e viabilidade econômica de cana-de-açúcar, sob diferentes lâminas de irrigação, na região de Penápolis

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Simulação da produtividade de cana-de-açúcar nas regiões nordeste e sudeste do Brasil, utilizando o modelo DSSAT

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

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.

Balanço hídrico, crescimento e produtividade de genótipos RB de cana-de-açúcar em cultivo de sequeiro na região de Rio Largo-AL

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Modelos agrometeorológicos estatísticos de previsão de produtividade e qualidade para cana-de-açúcar

Pós-graduação em Agronomia (Produção Vegetal) - FCAV

Utilização da modelagem sistêmica para analisar o efeito da variação climática no parâmetro produtividade da água na laranja Natal (Citrus sinensis L. Osbeck) no Estado de São Paulo

Pós-graduação em Agronomia (Irrigação e Drenagem) - FCA

Simulação da produtividade de cana-de-açúcar (Saccharum officinarum L.) na região nordeste do Brasil, utilizando o modelo DSSAT

The objective of this study was to simulate the potential stem and sugar yield of sugar cane (Saccharum officinarum L.) in the Northeastern Brazil (Petrolina-PE and Teresina-PI) and analyze 4 varieties in different planting seasons in two environments: irrigated and rainfed cultivars. The model of simulation was DSSAT/CANEGRO (Decision Support System for Agrotechnology Transfer) and the four sugar cane varieties were as follows: RB86 7515, CTC 4, CTC 7 and CTC 20 (all in 1.5 year cycle). Analysis of variance was performed on the results and means were compared using the Tukey test with probability level at 5%. March is the recommended month for planting in Teresina, PI. In Petrolina, PE, rainfed planting is not advisable because of the extended water deficit all year long. In an irrigated environment, no difference was found concerning stem yield as a function of planting season, for all varieties in the study regions. The stem and sugar yields were always higher in irrigated environment as compared with those in rainfed environment in all municipalities and study varieties. The simulation model provided good estimate of stem and sugar yields as compared with experimental data in Teresina, PI.

Modelos agrometeorológicos para previsão da produtividade e qualidade de bebida natural do cafeeiro

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Fisiologia, qualidade e produtividade da videira cv Syrah em diferentes estratégias de irrigação no semiárido

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

Fisiologia, qualidade e produtividade da videira cv Syrah em diferentes estratégias de irrigação no semiárido

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

Análise da variabilidade climática sobre a produtividade da soja no município de Bom Jesus (PI)

The climate is still main responsible for the variations soybean productivity (Glycine max (L.) Merrill), exerting a limiting action on these agricultural systems. The bomjesuense cerrado, this culture has proved, over the years, an increase of cultivated areas, however, productivity does not keep the same pace, going through periods of oscillations. Thus, although the crop is added to high technology, culture has great vulnerability to climatic adversities. Thus, the present study aims to analyze possible trends in meteorological variables, which can influence the soybean yield in Bom Jesus. For this purpose, different datasets were used, as follows: i) two periods of daily data (1984-2014 and 1974-2014), both obtained from the National Meteorological Institute (INMET); ii) climate normals from 1961-1990 as defined by INMET; iii) local agricultural production data of soybean-year (1997/1998 to 2012/2013) obtained from the Municipal Agricultural Production (PAM) dataset, which is management by Brazilian Institute of Geography and Statistics (IBGE). The analysis procedures included calculations of climate normals for 1984 to 2014 period and some statistical applications, as follows: i) the Wilcoxon test, used to evaluate differences between climate normals (1961 to 1990 and 1984 to 2014); ii) the Mann-Kendall nonparametric test, in order to analyze the linear trend of agrometeorological variables (rainfall, maximum temperature, minimum temperature and diurnal range of temperature; iii) cluster analysis by Ward method and the Spearman correlation test (rs) to identify the relationship between agrometeorological variable and soybean annual productivity. We adopted a statistical significance level of 5%. The results indicate changes in seasonality of the 1984-2014 climatology with respect to past climatology for all variables analyzed, except for insolation and precipitation. However, the monthly analysis of precipitation indicate negative trend during October and positive trend in December, causing a delay in start of rainy season. If this trend is persistent this result must be considered in futures definitions of the soybean crop sowing date over the region studied. With Mann-Kendall test was possible to identify positive trends with statistical significance in maximum temperature for all month forming part of soybean cycle (from November to April), which in turn tends to cause adverse effects on crop physiology, and consequently impacts on the final yield. Was identified a significant positive correlation between soybean yield and precipitation observed in March, thus precipitation deficit in this month is harmful to the soybean crop development. No statistically significant correlation was identified among maximum temperature, minimum temperature, and DTR with annual soybean productivity due these range of meteorological variables are not limiting factors in the final soybean yield in Bom Jesus (PI). It is expected that this study will contribute to propose planning strategies considering the role of climate variability on soybean crop final yield.