Tamanho de amostra para a estimativa das médias decendiais de radiação solar global no Estado do Rio Grande do Sul

Com o objetivo de verificar a variabilidade temporal e espacial do tamanho de amostra da radiação solar global média decendial, de 22 locais do Estado do Rio Grande do Sul, utilizaram-se séries de dados de radiação solar global do período de 1956 a 2003. Determinou-se o tamanho de amostra da radiação solar global média decendial em cada decêndio e local e agruparam-se os decêndios e os locais pelo método hierárquico 'vizinho mais distante'. Há variabilidade do tamanho de amostra (número de anos) para a estimativa da radiação solar global média decendial no Estado do Rio Grande do Sul no tempo e no espaço. Maior tamanho é necessário nos decêndios dos meses de junho, julho, agosto e setembro em relação aos outros meses. Para os locais e decêndios estudados, 30 anos de observações são suficientes para estimar a média (µ) de radiação solar global média decendial, para um erro de estimação igual a 12.3%, com coeficiente de confiança de 95%.

Estimativa da concentração espermática do sêmen de peixe pelo método de espermatócrito

Um experimento foi realizado com o objetivo de estimar a concentração espermática das espécies dourado (Salminus brasiliensis), curimba (Prochilodus lineatus), jundiá (Rhamdia quelen), cascudo-preto (Rhinelepis aspera) e tilápia-do-nilo (Oreochromis niloticus) pelo método de espermatócrito. Utilizaram-se 19, 58, 51, 43 e 85 reprodutores de dourado, curimba, jundiá, cascudo-preto e tilápia-do-nilo, respectivamente. Com exceção da tilápia-do-nilo, os reprodutores foram submetidos ao processo de indução hormonal e posteriormente submetidos a coleta de sêmen. Foram comparadas as técnicas de mensuração da concentração espermática do sêmen por contagem em câmara hematimétrica de Neubauer e por espermatócrito. Os resultados obtidos foram submetidos à análise de regressão a 5% de probabilidade. As concentrações espermáticas mensuradas por ambas as técnicas apresentaram relação linear, para curimbas, jundiás e tilápias-do-nilo, com equações y = 6,6624 × 10(9) + 3,68553 × 10(8)x; y = 2,153 × 10(9) + 4,426 × 10(8)x e y = -9,0897 × 10(8) + 6,0167 × 10(8), respectivamente. O método de espermatócrito pode ser utilizado para estimar a concentração espermática do sêmen de curimbas, jundiás e tilápias-do-nilo.

Estimativa do Tamanho da Primeira Maturação Sexual da Rã - Touro, Rana catesbeiana, no Sistema Anfigranja de Criação Intensiva

The objective of this research was to study the basic aspects of bullfrog reproduction in Anfigranja system from June 1989 to July 1990. For the 1493 animals involved in this experiment (657 males and 836 females) biometrical data were obtained (weight, length and tympanum diameter) and developmental stages of gonads were determined. Female sizes at first maturation were 10,33 cm and 109,78 g and for males it was around 8,09 cm; all males above 45 g were already in the maturation process. The relationship between tympanum diameter and body length (RTC) was considered a good index for male maturation.

Estimativa da captura total: desenhos amostrais para pesca artesanal

Estimating total landings of artisanal fisheries in managed areas is essential for the development of programs aimed at the establishment of sustainable production systems. However, few experiences addressed the constraints of assessments targeted at multispecific and small scale fisheries with pulverized landings. Total annual production (fish, lobsters and octopus) at the Marine Extractive Reserve of Corumbau, Bahia, Brazil, in 2006, was estimated through yields recorded by fisherfolks, in the scope of a participatory fisheries monitoring program. Three designs were employed: 1) simple random sampling, 2) stratified random sampling by month and fishing frequency, 3) stratified random sampling by community, fishing frequency and months, resulting in estimates of 349t (95% confidence interval = 305-393), 330t (289-372) and 315t (279-351), respectively. This kind of information can help design strategies for aggregation of value to small scale fisheries production, and also for the dimensioning of the corresponding infrastructure. However, these estimates shall not be used to support fishing effort increase, as there is high uncertainty regarding the state of the stocks, as well as limitations related to the asymmetry in monthly landings per fisherfolk and to the sampling coverage in the different strata.

Estimativa de variacao anual da reflexao da vegetacao atraves de imagens Landsat

Landsat images obtained in different periods were analysed with the aid of a transmission densitometer. Forest, pasture and crops were studied during Jan., April, July and Oct. and the results suggest the possibility of studying crop cycles using this method. -from Field Crop Abstracts

Estimativa do saldo de radiacao em Jaboticabal (SP)

This work deals with net radiation (Q*) estimates as function of solar radiation (K↓) for the Jaboticabal region in Sao Paulo State. In the same way shows a comparison between measured and Penman estimates net radiations. The data were 207 pairs of net and solar radiation obtained in a net radiometer and a Eppley Piranometer. The results show a good agreement between Q* and K↓ for two periods: spring-summer and autumn-winter. The Penman's equation for Q* underestimates the values for any station with albedo of 0.25. -English summary

Estimativa da mudança genética na produção de leite e gordura em bovinos da raça Holandesa

The objective of this study was to estimate the genetic trends of the milk and fat yield in three herds maintained in São Paulo State, Brazil. The estimation of genetic, environmental and phenotypic trends were based on 716 first lactations. The cows were sired by 134 bulls. The statistical models included the fixed effects of herds, kind of gestation, season and year of the calving, age of the cow at calving, besides the random effect of the bulls. The statistical analyses, by the last squares method showed effects for bulls, herds and age of the cows on milk and fat yield. The genetic, environmental and phenotypic trends estimated were -10.20; 6.74 and -3.46 kg for milk yield and -1.90; 2.20 and 0.12 kg for fat yield.

Estimativa do tamanho das fêmeas com ovos de Moina minuta Hansen, 1899 (Cladocera, Crustacea) no lago Amapá, Rio Branco, Estado do Acre Brasil

Moina minuta, a tropical species of Cladocera, was selected for the study of medium size at maturity and female egg production, due to its abundance and frequency in samples during low-water season in 1997 and high-water season in 1998, in Amapá Lake, Western Amazônia. The primiparous female had a size of 330 μm and 340 μm in low and high water, respectively. Moina individuals reached maximum size during high water (595μm). The medium size of the ovigerous females, in low water was 501 μm, producing an average of 4.41 eggs/female, while in high water, it was 533μm, with an average egg production of 4.84 eggs/female. The results, analyzed by the t test and Fischer's F test, showed that there were no statistical differences in size among individuals (t= -10.69, F=1.20 and P>0.1227), nor among ovigerous females (t= -4.45, F=1.02 and P>0.8906), considering the two seasons.

Estimativa do padrão de preferência térmica de matrizes pesadas (frango de corte)

Female broiler breeder productivity is based on the principles of thermal comfort that are directly related with the microclimate inside the housing. This research had the objective of monitoring the behavior of female broiler breeders, using the technology of radio-frequency, injectable transponders and readers in different existing microclimates inside a small scale distorted housing model. Eight birds with electronic identification were used. Three readers were used, in three different points inside the model: on the floor of the nest, in the passage besides the lateral wall and below the water facility. Dry bulb (DBT), wet bulb (WBT) and black globe (BGT) temperature were measured continuously. The results point out a distinct behavioral pattern of the birds regarding the environment exposition during the experiment. Three probabilistic models of behavior were developed from the recorded data: probabilistic model for the passage use: FP = 1.10 - 0.244 ln(DBT), probabilistic model for the water facility use: FB = 0.398 + 0.00866(DBT), and probabilistic model for the nest use: FN = 2.22 - 0.272 DBT + 0,011 DBT 2 - 0.000144 DBT 3.

Influência da acurácia de instrumentos de medidas na comparação de métodos de estimativa da evapotranspiração de referência

The aim of this investigation was to evaluate four reference methods to estimate evapotranspiration (Makkink, Hargreaves, Class A pan and Radiation), compared tb Penman-Monteith method, that is considered standard by the Food and Agricultural Organization of the United Nations (FAO). Errors due to variable measurements in the reference evapotranspiration estimate were taken into consideration. The research was developed in an experimental area of the Department of Rural Engieering of the School of Agricultural and Veterinarian Sciences, Campus of Jaboticabal, São Paulo State University. An automated weather station was used and it was equipped with sensors to measure global and net radiation, temperature, relative humidity, and wind speed. The aftermath showed a better adjustment to Hargreaves. Makkink, Class A pan and Radiation methods are different from Penman-Monteith, therefore, they cannot be compared. To evaluate methods to estimate evapotranspiration and avoid possible evaluation errors, ETo estimate errors must be considered.

Avaliação de interpoladores estatísticos e determinísticos na estimativa de atributos do solo em agricultura de precisão

The obtaining of the correct space distribution for attributes of the soil is relevant in the agricultural planning, in what concerns to the installation and maintenance of the cultures. The objective of that work was to compare statistical interpolation methods (ordinary krigagem) and deterministic methods (inverse square distance) in the estimate of CTC and V% in a distrophic yellow-red Latossolo. The study was accomplished in the State of Experimental Hands on of the Instituto Capixaba de Pesquisa, Assistência Técnica e Extensão Rural (INCAPER), in an irregular grading with 109 points. The data were collected in the layer of 0 - 0,20 m in the projection of the cup of the plants, in the superior part of the slope. The performance of the interpolators was obtained and compared using the criterion of the medium mistake. The observations are dependent in space until a maximum reach of 14,1 m, considering the isotropy. IDW presented larger mistake in the estimate of the data; however its difference in relation to KRIG was small for both variables.

Avaliação de duas estações meteorológicas automatizadas, para estimativa diária da evapotranspiração de referência obtida pelo método de penman-monteith

The objective of this study was to evaluate and compare measurements and estimates from Davis and Campbell Scientific Instruments in two automatic weather stations. Integrity of meteorological data for estimates of evapotranspiration of reference crop (ETo) from both stations was also evaluated. The following meteorological data were evaluated: air temperature, air humidity, wind speed, precipitation, net radiation and global solar radiation. The Penman-Monteith reference method to estimate ETo was evaluated daily. The weather stations were set up in an experimental area of the Rural Engineering Department-FACV/ UNESP, in Jaboticabal, State of Sao Paulo. Data were collected daily and statistical analysis was performed using linear regression analysis. The integrity of meteorological data to estimate ETo was evaluated. The results of the study in the stations using linear regression analysis showed that daily estimates for ETo had acceptable differences. The technique which evaluates the integrity of meteorological data revealed that data of relative humidity from both stations and of precipitation using Campbell Instruments were not good.

Estimativa do tempo de vida útil de represa de pequeno porte

The purpose of this work is to compare two methods for time estimation of useful life for a small and shallow reservoir, located in Pirassununga, São Paulo State, Brazil: 1) sedimentometry; and 2) bathymetry. The model indicated a useful lifetime around 50 years for the studied dam. The values are between 51 years for the initial years of 1998/1999, and 46 years for the final years of 2004/2005, with an oscillation between 1999/2000 of 27 years, and between 2000/2001 of 76 years. The results show that it is possible to estimate the useful lifetime for small dams through the sedimentometric method, by knowing the correction coefficient value (K'). The coefficient is calculated using time values of useful lifetime calculated by the sedimentometric and bathymetric methods simultaneously, during the span of one year.

Estimativa da exigência hídrica do amendoim usando um modelo agrometeorológico

In the experimental area of the Department of Environmental Sciences (21.85° S; 48.43° W; 786 m), in the School of Agronomical Sciences, UNESP, Botucatu, SP, an experiment was carried out using peanut (Arachis hypogaea L), cv. IAC-TATU-ST, to quantify the crop daily water requirements. During the peanut crop cycle, the environmental variables, such as rainfall, air temperature, air relative humidity, soil matric potential, soil heat flux and radiation balance, have been registered continually. These measurements were used to calculate the daily crop evapotranspiration, by the Bowen ratio method. The water replacement required by the peanut crop was done the dripping irrigation system, oriented by a dynamic agrometeorological model that computes the entrance and exit of water in the soil. During the peanut crop cycle, 9.0 mm of water was used from sowing to emergence; 67.0 mm of water, in the growth stage; 166.0 mm, in the flowering stage; 124.0 mm in the final stage and 46.0 mm from physiological maturity to harvest. Oot of 412.0 mm of the total consumption, 246.0 mm of water was supplied by irrigation and 166.0 mm by the rain. The grain yield was 3.15 t ha-1 for 15% of humidity, and the water use efficiency was 0.764 kg m-3.

Proposição e validações de equações para estimativa da erosividade de dois municípios do estado de São Paulo

The equations and extrapolation use to localities whose characteristics of soil and climate, even if partial, distinguish the town to which they were generated, still permeate in studies to estimate the rainfall erosivity (EI 30). This work has objective to propose and validate mathematical equations to estimate the rainfall erosivity of two cities of Sao Paulo State's. The adjusted to estimate obtaining and validate data of equations of erosivity (EI 30) according to values of coefficient of rain (Rc) were obtained from pluviographic and pluviometric rainfall data, respectively, using of distinct historical rainfall series. Mutiple comparisions test and confidence intervals were performed to compare absolute average of EI 30, pluviometric data (Pp), and Rc. The correlation between EI 30 and Rc was verified by of Pearson correlation coefficient. Test of the hypothesis of equality between population variance was used to compare the equations. Pluviometrics data of historical series rainfall data different than those that the models were generated were used to validate and to assess the performance of the equations, proposed of this study and compare them with another equation already consolidated in literature. The results show that for the conditions under which the study was conducted, the simple linear equations, shown to be the most appropriate to estimate the rainfall erosivity these two cities. According to the test of the hypothesis of equality variances between populations, the equations adjusted for each city differ statistically so that the rainfall erosivity of each city must be estimated by their respective equation.