Management practices can affect the phenology and, consequently, the harvest time and crop production level of forage cactus. This study aimed at evaluating the effect of irrigation depths and cropping systems on the phenophases and cutting time of the forage cactus Opuntia stricta (Haw.) Haw. The experimental design was a randomized block with split plots and four replications. Irrigation depths based on reference evapotranspiration (8.75 %, 17.5 %, 26.25 % and 35 % ETo) and a control (0 % ETo) made up the plots, while cropping systems (exclusive cropping, exclusive cropping on mulch and forage cactus-sorghum intercropping) were distributed in the subplots. Cladode emission morphogenesis was used to define the phenological phases, while the extrapolation of the monthly dry matter accumulation rate was applied to obtain the cutting time. The use of irrigation depths significantly increased the phenophase II (higher emission of second-order daughter cladodes), decreasing the phenophase III, associated with third-order daughter cladodes. The phenophase III was lower in the exclusive cropping on mulch and forage cactus-sorghum intercropping systems, when compared to the exclusive cropping system. The ideal cutting time for irrigated forage cactus is 19 months, regardless of the cropping system. The exclusive cropping on mulch and forage cactus-sorghum intercropping systems significantly increased the monthly forage dry matter accumulation rate, with an earlier cutting time for the forage cactus-sorghum intercropping system (17 months).

RESUMO: O atual cenário agrícola mundial evidencia a necessidade do emprego de dispositivos para o monitoramento dos processos produtivos e aquisição de informações que subsidiem a tomada de decisão. Nesse sentido, objetivou-se com este trabalho comparar dados de temperatura e umidade relativa do ar obtidos a partir de sensores de baixo custo, protegidos em um abrigo meteorológico confeccionado a partir de PVC, com dados de duas estações meteorológicas para fins de aferição. Os sensores utilizados foram o LM35DZ, para a temperatura do ar, e o HIH-4030-4031, para a umidade relativa do ar. Foram confeccionadas placas de circuito impresso para acomodação e condicionamento do sinal dos sensores teste de temperatura e umidade relativa do ar. Os equipamentos foram instalados em condições de campo, nas estações meteorológicas automáticas localizadas em Juazeiro-BA e Petrolina-PE, sendo os circuitos dos sensores teste conectados a um data logger desenvolvido na Universidade Federal do Vale do São Francisco (UNIVASF). A partir da coleta dos dados, foram realizadas análises estatísticas de regressão. Com a similaridade encontrada entre os dados obtidos a partir dos sensores protegidos em abrigo de PVC com os dados obtidos a partir dos sensores utilizados nas estações meteorológicas da UNIVASF e da Embrapa Semiárido, foi comprovada a viabilidade de uso em condições de campo do LM35DZ e do HIH-4030-4031 em abrigo confeccionado com PVC. A confiabilidade dos dados obtidos mostrou ser possível reduzir custos nas atividades agrícolas e de pesquisa acadêmica que envolvam a medição dessas variáveis ambientais. PALAVRAS-CHAVE:Data logger, policloreto de vinila, variáveis ambientais. ABSTRACT:The current global agricultural scenario shows the need for devices that monitor production processes and the acquisition of information that support decision making. In this sense, the aim of this work was to compare data from temperature and relative humidity obtained from low cost sensors, protected in a weather shelter made from PVC, with data from two weather stations for the purpose of benchmarking. The sensors used were LM35DZ to measure the air temperature, and the HIH-4030-4031, to measure the relative humidity. Printed circuit boards were made for accommodation and signal conditioning of the temperature and relative humidity test sensors. The equipment was installed in field conditions at the automatic weather stations located in Juazeiro-BA and Petrolina-PE, and the test circuits of sensors were connected to a data logger developed at the Federal University of Vale do São Francisco (UNIVASF). A statistical regression analyzes was performed to analyze the data. The similarity found between the data obtained from the protected shelter of PVC with data obtained from sensors used in weather stations from UNIVASF and Embrapa Semi-Arid sensors, proved the feasible of using the LM35DZ HIH and 4030-4031 made with PVC in field conditions. The reliability of the data obtained proved that is possible to reduce costs in agricultural activities a...

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The spatial variability in meteorological conditions was evaluated in two small ruminant house with different constructive aspects, based on the variables of dry bulb temperature, relative humidity, wind speed and temperature humidity index (THI), through the generation of maps using the Kriging interpolation method. The experiment was conducted in two seasons, winter and summer, and the small ruminant house were denominated as: FNRG (facility at ground level with no ridge vent) and FWRG (facility at ground level and with ridge vent). The studied parameters were recorded by portable digital sensors, thermo-anemometers and thermo-hygrometers, with data collections at 9 am and 3 pm. With the analysis of the spatial variability of the data, it was observed that the pens positioned in the central region of the two facilities had the least stressful places to animals in two seasons and two times, where the FWRG presented larger areas with lower temperatures, within the comfort zone, compared to the FNRG due to the presence of the ridge vents, were the least stressful places for the animals in the two seasons and at the two data collection times. At 9 am, in the winter and summer, both facilities presented comfortable conditions for the rearing of goats and sheep in the morning that were not observed at 3 pm.