Zoneamento bioclimático para vacas leiteiras no Estado de Pernambuco.

Foram utilizados os dados de temperatura e umidade relativa do ar de 252 localidades distribuídas pelo Estado de Pernambuco, com o objetivo de realizar um zoneamento bioclimático para o referido estado, baseando-se nos valores do índice de temperatura e umidade (ITU) para os meses mais quentes do ano. Os valores de IU obtidos variaram de 68 a 79, sendo que as microrregiões que apresentaram menores valores do ITU foram a do Vale do Ipojuca, Vale do Ipanema e Garanhuns, onde estão localizados os principais municípios produtores de leite, segundo dados do IBGE (2003). As microrregiões situadas próximas ao litoral e inserida na região semi-árida nordestina foram as que apresentaram condições climáticas mais desfavoráveis para o conforto térmico animal. Assim, para tais regiões a utilização de técnicas manejo e de condicionamento térmico torna-se de fundamental importância para reduzir as perdas de produtividade pelo gado leiteiro

Espacialização do declínio na produção de leite para condições de verão no Estado de Pernambuco.

A partir dos dados de temperatura e umidade relativa do ar de 252 localidades distribuídas por todo Estado de Pernambuco, foi possível espacializar as possibilidades de declínio da produção de leite (PDL) para seis níveis normais de produção, dentro do referido Estado. As maiores possibilidades de redução na produção de leite foram observadas na microrregiões situadas próximas ao litoral e inserida na região semi-árida nordestina. Em tais regiões observou-se que, para os níveis de produção (NP) de 10, 15, 20, 25, 30 e 35 kg/vaca/dia as perdas podem atingir valores em torno de 1,0; 2,2; 3,4; 4,3; 5,5 e 6,4 kg/dia, respectivamente. Sendo assim, a utilização de técnicas de acondicionamento térmico torna-se de fundamental importância para evitar perdas de produção pelo gado leiteiro nessas regiões

Non–Water–Stressed Baseline as a Tool for Dynamic Control of a Misting System for Propagation of Poinsettias

A technique is presented for dynamically adjusting misting intervals during propagation of vegetative cuttings. A crop setpoint temperature for activation of misting was defined by a non-water-stressed baseline concept, using infrared thermometry to acquire canopy temperature for plant feedback. The critical crop setpoint temperature was calculated from instantaneous values of air temperature, incident radiation, and air vapor pressure deficit (VPDair). Misting was activated when the actual crop temperature exceeded the critical crop setpoint temperature. The dynamic control was shown to have the potential to reduce the amount of applied water from 9 to 12 times during low levels of VPDair (0.8 to 1.1 kPa) and under dark conditions when compared to a conventional on/off misting interval of 5 s each 5 min. In addition, misting intervals were reduced three-fold, from 30 to 11 min, when incident radiation increased from 0 to 100 W m-2 and VPDair was maintained in the range from 2.3 to 2.6 kPa. Further increases in radiation levels from 200 to 300 W m-2 did not appreciably change the misting frequency. The dynamic misting control provides a large potential for increasing the period between misting events under dark conditions and with low to moderate levels of incident radiation. It automatically increases misting frequency as VPDair and/or radiation increase

Association of morphological and water factors with irrigated forage cactus yield

This study aimed to understand the relationship of morphological characteristics and actual evapotranspiration of forage cactus clones with their productive capacity under different water regimes. The data used in this study were collected between the years 2012 and 2013, in Serra Talhada, State of Pernambuco. The clones Sertânia IPA - IPA, Miúda - MIU and Orelha de Elefante Mexicana - OEM were submitted to three irrigation depths (2.5, 5.0 and 7.5 mm) and three irrigation intervals (7, 14 and 28 days). Cladode and plant morphology, accumulated actual evapotranspiration and yield were obtained at the moment of harvest. Pearson’s correlation matrix was elaborated and, in the sequence, multicollinearity, canonical and path analysis were applied. There was no correlation of yield with the soil water supply and actual evapotranspiration of the clones (p > 0.05). Forage cactus yield was more associated with peculiarities of the morphological characteristics of the clones than with the different soil water supplies or the crop actual evapotranspiration. However, regardless of the water regime and clone, the vigor of the basal cladodes was highly decisive for the expression of the forage cactus productive capacity.Objetivou-se, neste trabalho, compreender a relação de características morfológicas e da evapotranspiração real de clones de palma forrageira com sua capacidade produtiva em diferentes regimes hídricos. Os dados usados nesta pesquisa foram coletados entre os anos de 2012 e 2013, em Serra Talhada, PE. Os clones IPA Sertânia - IPA, Miúda - MIU e Orelha de Elefante Mexicana - OEM foram submetidos a três lâminas (2,5; 5,0; e 7,5 mm) e três intervalos de irrigação (7; 14 e 28 dias). Dados morfológicos dos cladódios e da planta, evapotranspiração real acumulada e desempenho produtivo foram obtidos na ocasião da colheita. A matriz de correlação de Pearson foi elaborada e, em seguida, foram aplicadas análises de multicolinearidade, canônica e de trilha. Não houve correlação da produtividade com o suprimento de água e evapotranspiração real dos clones (p > 0,05). A produtividade da palma esteve mais associada a peculiaridades das características morfológicas dos seus clones do que aos diferentes suprimentos de água no solo ou à evapotranspiração real da cultura. Mas, independente do regime hídrico e do clone, o vigor do cladódio basal foi bastante decisivo para a expressão da capacidade produtiva da palma forrageira irrigada

Computational fluids dynamics (CFD) in the spatial distribution of air velocity in prototype designed for animal experimentation in controlled environments

ArticleMaintaining a comfortable and productive thermal environment is one of the major challenges of poultry farming in tropical and hot climates. The thermal environment encompasses a number of factors that interact with each other and reflect the actual thermal sensation of the animals. These factors characterize the microclimate inside the facilities and influence the behaviour, performance and well-being of the birds. Thus, the objective of this study is to propose and validate a computational model of fluid dynamics to evaluate the spatial distribution of air velocity and the performance of a system designed to control air velocity variation for use in experiments with birds in controlled environment. The performance of the experimental ventilation prototype was evaluated based on air velocity distribution profiles in cages. Each prototype consisted of two fans coupled to a PVC pipe 25 cm in diameter, one at each end of the pipe, with airflow directed along the entire feeder installed in front of the cages. The contour conditions considered for the simulation of airflow inside the cage were air temperature of 35 °C at the entrance and exit of the cage; air velocity equal to 2.3 m s -1 at the entrance of the cage; pressure of 0 Pa. The model proposed in this study was representative when compared to the experimental measurements, and it can be used in the study of air flow behaviour and distribution for the improvement of the prototype design for later studies

Forage cactus-sorghum intercropping at different irrigation water depths in the Brazilian Semiarid Region.

The objective of this work was to evaluate the productive performance, biological efficiency, and the competitive ability of the forage cactus-sorghum intercropping under different irrigation depths with saline water in the Brazilian Semiarid Region. The experiment was carried out in Serra Talhada, in the state of Pernambuco, between 2014 and 2015, in a randomized complete block design, with four replicates, and a 5x3 factorial arrangement in split plots, with one year of forage cactus cycle and two years of sorghum cycles. The plots were composed by four irrigation water depths based on the fractions of 25, 50, 75, and 100% of the reference evapotranspiration, besides dry conditions; and the subplots consisted of three cropping systems (single crop of forage cactus, single crop of sorghum, and intercropping of forage cactus-sorghum). The increase of water irrigation depths increased the yields of sorghum in single crop and of the forage cactus-sorghum intercropping. The intercropping system promoted production stability with a higher system productivity index (SPI) for forage cactus-sorghum intercropping (6,279.02 kg ha-1 DM) than for forage cactus in single crop (4,626.98 kg ha-1 DM). The relative density coefficient (12.33) was indicative of the great compatibility of the intercropping system. The forage cactus-sorghum association shows biological advantage and competitiveness capacity, with a higher productive index than their monocultures.Título em português: Consórcio palma-sorgo irrigado com diferentes lâminas de água no Semiárido brasileiro