Adilson Pacheco de Souza

Temperaturas basais e soma térmica para a figueira podada em diferentes épocas

It was determined for the fig trees pruned in July, August, September and October, the most minimum and maximum basic temperatures, the thermal sum express in degree-days and the influence of the temperature in the duration of the period between the prune and the beginning of the harvest, in Botucatu - SP, from 2002 to 2006. The estimated values of minimum and maxim basal temperature were 8oC and 36 oC, respectively. The prune periods that presented better results in seasonal variation and productivity were August and July, and it was necessary a medium thermal sum of 1955 and 2200 degree-days.

Estimativas das componentes da radiação solar incidente em superfícies inclinadas baseadas na radiação global horizontal

ABSTRACT Statistics equations and validations with groups of annual and monthly data were evaluated for global,direct and diffuse solar radiation components incident on the tilted surface to 12.85, 22.85 and 32.85°with the face North, in climate and geographical conditions of Botucatu, SP. It was employed the fractionsof three components of extraterrestrial radiation in correlation with the coefficient clearness indexhorizontal plane, in a database of April/1998 to December/2007, whose measures at different periods inthree inclinations, however concomitant to the horizontal plane. Increasing the angle of the surface ledto increased scattering of the daily values of clearness index for inclined and horizontal surfaces. Inannual groups, the lower performances were observed in the estimation of inclined daily diffuse radiation,with maximum Root Mean Square Error to 3.89 MJ m -2 d -1 (43.65%) and adjustments around 62%. Inestimates of global and direct components of solar radiation on inclined planes, both annual andmonthly equations can be applied, with performance dependents to climatic conditions.

Estimativas da evapotranspiração de referência em diferentes condições de nebulosidade

The objective of this work was to evaluate the performance of reference evapotranspiration (ETo) estimation methods, in different cloudiness conditions, in Seropedica, RJ, Brazil. The ETo estimates were compared with daily measurements made on weighing lysimeter, between 6/1/2006 and 7/31/2007, by pooling the data or discretizing them according to the variance of daily clearness index (KT), in four classes: KT 0.65, open sky (Op). The mean absolute error (MBE), the square root of the mean square error (RMSE) and indexes of adjustment and performance were used as quality indicators of the different methods. In the pooled data, Penman-Monteith FAO (PMF) and Hargreaves-Samani (HS) methods had 84.05 and 79.52% performance indexes, respectively, while Jensen & Haise, Linacre and Makking methods had performances below 60%. Changes in the cloudiness conditions affected the performance of ETo estimation methods. The best results were obtained with the solar radiation (86.1%) and Camargo (81.8%) methods, under the Op and Clo conditions. The PMF and HS methods can be employed in a complementary way, since their performance were 78.4% (Clo and PCDi) and 77.6% (PCOp and Op), respectively.

Coeficientes da equação de Angström-Prescott e sua influência na evapotranspiração de referência em Seropédica, RJ

ABSTRACT The reference evapotranspiration (ETo) is dependent on the amount of energy available in the environment,being solar radiation (SR) as an important variable in its estimation. This study was carried out in order todetermine the coefficients “a” and “b” of the Angstron-Prescott equation for Seropedica, Rio de JaneiroState, Brazil, and to evaluate their effects on the SR and ETo estimation. Measures of global solar radiationand effective number of hours of sunshine were used from station Ecology Fund (83741 - INMET) for theperiod of 2000 to 2007. The coefficients were determined by linear regression analysis for the entireperiod and monthly and yearly periods. Using the calculated coefficients and those proposed by FAO(0.25 and 0.50) SR and ETo were estimated and evaluated their performance. The average monthlycoefficients “a” ranged from 0.232 to 0.299 and “b” from 0.397 to 0.504. Annual mean coefficients “a”and “b” were 0.295 and 0.417, and for general period were 0.282 and 0.433, respectively. The bestperformance observed for the estimated SR and ETo was obtained when the monthly coefficients of theequation Angstron-Prescott were adopted.

Desempenho da alface em cultivo orgânico com e sem cobertura morta e diferentes lâminas d'água

O experimento foi conduzido no periodo de 27/05/2006 a 02/08/2006 no SIPA (Sistema Integrado de Producao Agroecologica), localizado no municipio de Seropedica-RJ. Nesse trabalho, objetivou-se avaliar o desempenho da cultura da alface (Lactuca sativa L.) cultivada sob diferentes lâminas de irrigacao em um solo sem e com cobertura de palhada da leguminosa gliricidia. Foram conduzidos dois experimentos simultâneos, utilizando o delineamento experimental de blocos ao acaso, em ambos os experimentos, nos quais foram aplicadas 5 lâminas de irrigacao, correspondendo a 25, 50, 80, 100, 115 % da evapotranspiracao da cultura (ETc), sendo a producao final avaliada por meio da determinacao da massa fresca, area foliar e numero de folhas. Ate o nivel de 100% ETc, todas as variaveis analisadas tiveram seus valores aumentados, e para o nivel de 115%, houve um decrescimento das mesmas. Na producao de massa fresca total, o sistema de cultivo com utilizacao de cobertura morta foi superior ao sem cobertura nao diferenciando estatisticamente ao nivel de 5 % probabilidade pelo teste F somente nas lâminas de 25 e 115% ETc.

Estimativa da evapotranspiração de referência a partir de dados meteorológicos limitados

The objective of this work was to evaluate the estimate of reference evapotranspiration (ETo) for the Southeast Region of Brazil using limited meteorological data. The FAO 56 Penman-Monteith method (PMp) was used as reference. Three scenarios of limited meteorological data, obtained from automatic network stations, were used for estimating ETo: standard method (PMp), with solar radiation estimated from the balance between short and wide wavelengths (PMKrs); standard method using vapor pressure estimated from minimum and maximum temperatures, and from air relative humidity (PMea); and standard method using constant wind speed (2 m s-1; PMu2). ETo was also estimated by the Hargreaves-Samani (HS) and Turc methods. The models were analyzed by statistical indicators of mean absolute deviation (MBE), relative error (RE), root mean square error (RMSE), and Willmott index (d). The PMea method is the best alternative to estimate ETo, followed by PMu2, for the states of Espirito Santo and Rio de Janeiro, and PMKrs, for the states of Sao Paulo and Minas Gerais. The largest errors are obtained with the Hargreaves-Samani method, which overestimated ETo compared with PMp, for most of the evaluated stations.

Desempenho do cultivo da berinjela em plantio direto submetida a diferentes lâminas de irrigação

Este estudo foi conduzido no municipio de Seropedica, RJ, com o objetivo de se determinar, em cultivo orgânico e sistema de plantio direto, a produtividade da cultura da berinjela sob diferentes lâminas de irrigacao e sistemas de cultivo (consorciada com leguminosa e solteira). O delineamento experimental adotado foi o de blocos ao acaso, no esquema de parcela subdividida com quatro repeticoes caracterizando, na parcela, os tratamentos equivalentes a lâmina de irrigacao (40; 70; 100 e 120% ETc) e, na subparcela, os sistemas de cultivo consorciado com feijao caupi e solteiro. Ambos os sistemas de cultivo nao influenciaram a produtividade final da berinjela; no entanto, considerando as diferentes lâminas, a maior produtividade comercial foi de 65,41 Mg ha-1, obtida para uma lâmina total de 690,04 mm (106,8% ETc). A menor lâmina aplicada resultou em qualidade inferior dos frutos em relacao as maiores lâminas, sendo a taxa de descarte dos frutos de 3 e 14%, respectivamente, para a maior e a menor lâmina.

Estimativa da radiação global incidente em superfícies inclinadas por modelos isotrópicos e índice de claridade

The objective of this work was to evaluate the performance of isotropic models estimative of the global radiation on tilted surfaces and to propose estimations based on correlation between the clearness index for horizontal and tilted surfaces, for different sky conditions, in Botucatu, SP, Brazil. The isotropic model proposed by Liu & Jordan, Revfeim, Jimenez & Castro, Koronakis, the Circunsolar theory and the correlation between the clearness index for horizontal and tilted surfaces, for different sky conditions, evaluated tilted surfaces at 12.85o, 22.85o, and 32.85o. Global irradiation database used corresponds to the period from 1998 to 2007, with intervals from 4/1998 to 8/2001 for the surface tilted at 22.85o, from 9/2001 to 2/2003 for the surface tilted at 12.85o and from 1/2004 to 12/2007 for the surface tilted at 32.85o. The performance of the models was analyzed using the statistical indicators mean bias error, root mean square error and d-Wilmott. The models of Liu & Jordan, Koronakis and Revfeim showed the best performance on cloudy days considering all the tilted surfaces. The sky coverage partially diffuse and partially clear with the largest tilted angles showed the highest scattering between estimated and measured values, irrespective of the model. Statistical equations showed good results in monthly average data applications.

Evapotranspiração de referência estimada por modelos simplificados para o Estado do Mato Grosso

The objective of this work was to evaluate the performance of 12 simplified models for the estimation of reference evapotranspiration (ETo) for the state of Mato Grosso, Brazil. The data were collected from automatic weather stations (AWS) of the Instituto Nacional de Meteorologia, located in 28 municipalities of the state. The following simplified estimation models were evaluated: Hargreaves-Samani, Camargo, Makkink, Linacre, McGinness-Bordne, Romanenko, Turc, Holdridge, Solar Radiation, Jensen-Haise, Hansen, and Caprio. The Fao 56 Penman-Monteith method (FPM) was used as reference for assessing the simplified estimates. Statistical performance was evaluated through relative mean error (RME), root mean square error (RMSE), Willmotts d index, and according to the numerical order of models for each index. The Makkink model overestimated ETo by 2.0 to 3.0 mm per day, with scattering values of 2.75 mm per day and 0.40 d index, which represented the worst results among models, regardless of the municipality evaluated. The Turc and McGinness-Bordne models showed the best performances for estimating ETo in 57.1 and 25% of the AWS, respectively. The Romanenko, Makkink, and Holdridge models are not recommended for the state of Mato Grosso, Brazil.

Annual evolution of global, direct and diffuse radiation and fractions in tilted surfaces

It was evaluated the annual evolution of global, direct and diffuse components of incident solar radiation on tilted surfaces to 12.85, 22.85 and 32.85o, facing north, in Botucatu, state of Sao Paulo, Brazil. The radiometric fractions were obtained for each component of the radiation in the aforementioned surfaces, through the ratio with the global and top of the atmosphere radiations. Seasonality was evaluated based on monthly averages of daily values. The measures occurred between 04/1998 and 07/2001 at 22.85o; 08/2001 and 02/2003 at 12.85o; and from 03/2003 to 12/2007 at 32.85o, with concomitant measures in the horizontal surface (reference). The levels of global and direct radiation on tilted surfaces were lower in summer and higher in the equinoxes when compared with the horizontal. The diffuse radiation on tilted surfaces was lower in most months, with losses of up to 65%. A trend of increasing differences occurred between horizontal and tilted surfaces with the increase of the angle in all the components and fractions of incident radiation. The annual evolution of rainfall and cloud cover ratio directly affected the atmospheric transmissivity of direct and diffuse components in the region.