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Cavalieri J.D.,Sao Paulo State University | Raetano C.G.,Sao Paulo State University | Madureira R.P.,Federal University of Vicosa | Moreira L.L.Q.,IFNMG
Engenharia Agricola | Year: 2015

Tractor traveling speed can influence the quality of spraying depending on the application technology used. This study aimed to evaluate the droplet spectrum, the deposition and uniformity of spray distribution with different spraying systems and traveling speeds of a self-propelled sprayer in two phenological stages of the cotton plant (B9 and F13). The experimental design was randomized blocks and treatments were three spraying techniques: common flat spray tips; tilted flat jet with air induction, at 120 L ha-1; and rotary atomizer disk, 20 L ha-1, combined with four traveling speeds: 12, 15, 18 and 25 km h-1, with four replications. Spraying deposition was evaluated for both leaf surfaces from the cotton plant apex and base (stage B9) and middle part of the plant (stage F13) with a cupric marker. A laser particle analyzer also assessed the droplet spectrum. The centrifugal power spray system produces more homogeneous droplet spectrum and increased penetration of droplets into the canopy in both phenological stages. Variation on the operating conditions necessary for increased traveling speed negatively influences the pattern of spraying deposits. Source


Martins S.C.S.G.,UNIMONTES | Rocha Junior V.R.,UNIMONTES | Caldeira L.A.,UNIMONTES | dos Reis T.,UNIMONTES | And 4 more authors.
Revista Brasileira de Zootecnia | Year: 2012

The objective of this study was to evaluate the physical-chemical and sensory quality and fatty acid profile of Minas cheese produced from milk from crossbred cows fed diets with four roughages (sugar cane, sorghum silage, sunflower silage and pasture of Panicum maximum cv. Tanzania). Yield, physical-chemical composition, fatty acid profile and sensory analysis of Minas cheese, as well as the physical-chemical composition of milk were analyzed. For the experiment, eight 1/2 Holstein/Gir crossbred cows, with lactation period of 180 ± 12 days were distributed in two 4 × 4 latin squares (four animals, four diets and four periods). The experimental periods had a duration of 18 days: 15 days of adaptation and three days of data collection. After cheese processing microbiological, physical-chemical and sensory analysis were done. Cheese samples were frozen and analyzed for fatty acid profile. The fat content of cheese was higher for diets with sugar cane and sunflower silage compared with sorghum silage and pasture of Panicum maximum cv. Tanzania. Cheese produced from milk from cows fed sunflower silage had superior fatty acid composition and nutritional quality indexes, and better profile and higher proportion of unsaturated fatty acids. Cheese yield did not differ between diets containing different roughages. Cheese produced from milk from cows fed a diet with sunflower silage presents higher preference at the sensory analysis test, especially regarding the attribute appearance. © 2012 Sociedade Brasileira de Zootecnia. Source


We evaluated the production of Eucalyptus urophylla, E. camaldulensis and Corymbia citriodora in pressed blocks and two tubes models by the evaluation of survival and early growth of seedlings. We assessed survival at sixty days and initial growth in height and diameter at ground level to the tenth month after planting. We used a randomized block design with five replications. Seedlings of E. urophylla and E. camaldulensis produced in blocks, and in two tube models, and seedlings of C. citriodora produced in two tube models had high survival rates. On the other hand, seedlings of C. citriodora produced in blocks presented the lowest survival mean. The initial seedling growth mean of E. urophylla produced in blocks and tubes of 50 cm3 were higher than for seedlings grown in tubes of 35 cm3. In relation to E. camaldulensis and C. citriodora the average initial growth were similar in the three containers. Production of seedlings of E. urophylla is recommended in tubes of 50 cm3 or in compressed blocks, E. camaldulensis seedlings can be produced in three containers, and C. citriodora in tubes of 50 and 35 cm3. Source


The objective of this study is to characterize and evaluate factors of work environment in a nursery for clonal propagation of Eucalyptus spp., in order to improve health, welfare, safety, comfort and productivity of the workers involved in such activity. Factors characterized in work environment: thermal sensations (temperature, humidity and wind speed), noise and light were obtained by direct observation of the work unit and measurement of physical agents, it was evaluated sectors of cleaning and disinfection of tubes and trays, tubes and filling boxing, substrate preparation, clonal garden, staking, greenhouse, shade and growth in the open. Evaluated activities that present inadequate levels, surpassing the allowed limits are as follows: the greenhouse (temperature and humidity); garden and clonal growth in the open (light) substrate preparation and filling of tubes (noise) and speed wind (open activities). Source


Vilela M.S.,Instituto Federal Goiano | Filho F.R.C.,Instituto Federal Goiano | Teixeira M.B.,Instituto Federal Goiano | Amaral A.M.,IFNMG | Vellame L.M.,Nucleo de Engineering de Agua e Solo
IRRIGA | Year: 2015

To apply a blade of adequate irrigation is necessary to know the crop water demand, estimating precisely its evapotranspiration for efficient irrigation management. The evapotranspiration of culture can be determined precisely by the use of electronic or mechanical weighing lysimeters. The objective of this study was to development and calibration of a mini-lysimeter mechanical weighing low cost for the determination of the reference evapotranspiration. The mini-lysimeter consists of a PVC tank, resting on fixed metal shields, with a drain at the base of the tank, the load cells (four cells) are derived from a domestic weighing balance. The system acquisition and storage of data using a micro-controller. For calibration of the lysimeters was used reference masses consisting of 4 units (10, 5, 0.5 and 0.2 kg) were added in increasing and decreasing order in 5 measuring cycles in order to obtain the calibration curve of equipment. Were calculated the maximum absolute error, repeatability errors, linearity and hysteresis of the instrument. There has been a trend in deviations from the applied resulting mass calibration, the higher the maximum applied load (35.7 kg), with a value of -1.52 kg. The non-linearity error it was what influenced more in accuracy of the mini-lysimeter with 1.68 kg and 7.93 of influence in the measurement, us cycles of loading and unloading, respectively. The Hysteresis showed low interference in the measurement, 0.06%. The maximum absolute error showed a high value of 1.5 kg (0.35%), requiring new settings on your hardware and load cells. © 2015, Universidade Estadual Paulista - UNESP. All rights reserved. Source

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