Santos F.L.,FCA UFGD |
de Queiroz D.M.,Campus Universitario |
Pinto F.A.C.,Campus Universitario |
de Resende R.C.,Campus Universitario
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2010
Quality parameters influence directly the coffee price. However, selective coffee harvesting is frequently associated to good quality of this product. This procedure can be performed by mechanical vibration. Therefore, the study of the frequency and amplitude parameters is important for the design of a specific harvesting machine. The objective of this work was to evaluate the effect of the frequency and amplitude of vibration, the coffee variety and the ripeness condition of the fruits upon the harvesting efficiency. The vibration tests were done in laboratory using an electromagnetic shaker. The tests were done using amplitudes in the range of 3.75 to 7.50 mm and frequencies in the range of 13.33 to 16.67 Hz. Branches of coffee plants of Mundo Novo variety were tested. The highest harvesting efficiency was obtained when using the 26.67 Hz frequency of vibration. The highest harvesting efficiency was obtained when an amplitude of 7.5 mm was used. It was also observed that the number of fruits per stem influences the harvesting efficiency of the coffee fruits of the Mundo Novo variety.
Gomes E.P.,FCA UFGD |
Rickli M.E.,DMV UEM |
Cecato U.,State University of Maringa |
Vieira C.V.,University of Campinas |
And 2 more authors.
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2015
The study was conducted on a dairy farm in the municipality of Xambre, Northwest region of Parana, in the period from March 2011 to February 2012 to evaluate the yield and botanical composition of Tifton 85 with and without irrigation under nitrogen doses. The experimental plots were implanted in completely randomized blocks with and without irrigation and subplots through four nitrogen levels: 0, 20, 40 and 60 kg ha-1 per grazing cycle, with four replications. The yield in dry matter (DM) was higher under irrigation, responding linearly to increasing nitrogen fertilization. At a dose of 60 kg N ha-1 yields of 39279 and 27826 kg DM ha-1 were obtained, with and without irrigation, respectively. The leaf stem ratio was not affected by irrigation. The overall mean percentage of dead material with and without irrigation was equal to 13 and 17%, respectively. © 2015, Departamento de Engenharia Agricola - UFCG/Cnpq. All rights reserved.
Gordin C.R.B.,Federal University of Grande Dourados |
Marques R.F.,Engenheiros Agronomos |
Rosa R.J.M.,Engenheiros Agronomos |
Dos Santos A.M.,Engenheiros Agronomos |
De Paula Quintao Scalon S.,FCA UFGD
Semina:Ciencias Agrarias | Year: 2013
Jatropha curcas L. is a potential oilseed crop for biodiesel production with scarce information about the aluminum effect on the emergence and early growth. This work aimed to evaluate the seed germination and early plant growth of Jatropha plants subjected to aluminum in the irrigation water. Seedlings emergence was evaluated in the presence of five concentrations of aluminum chloride hexahydrated (AlCl3.6H2O) in irrigation water: 0, 5, 10, 15 and 20 mmol L-1. Data was taken on percentage of seedling emergence, speed index, average time for emergence, height, root lengths and shoot and root dry weights. In another experiment, the plants were raised in absence of aluminum up to 25 days after sowing (DAS) and then subjected to the same aluminum concentration in the first experiment. Data was taken on survival rate, chlorophyll content, leaf area, height, root length and shoot and root dry weights. The emergence and speed index of Jatropha seedlings was reduced by the increased aluminum concentrations in irrigation water, with a decrease in seedling emergence of 98% at concentration of 20 mmol L-1. The plants exposed to aluminum at 25 DAS had leaf edge rolling, leaf chlorosis and necrosis, and reduced survival rate, leaf area, chlorophyll content, and shoot and root lengths and dry weights. Therefore, the aluminum in solution affect the seedlings emergence and early growtht of Jatropha plants, observing its toxic effect from the concentration of 5 mmol L-1.
Nascimento G.R.,University of Campinas |
Naas I.A.,University of Campinas |
Pereira D.F.,Sao Paulo State University |
Baracho M.S.,University of Campinas |
Garcia R.,FCA UFGD
Revista Brasileira de Ciencia Avicola | Year: 2011
This study was conducted to determine the effect of the air temperature variation on the mean surface temperature (MST) of 7- to 35-day-old broiler chickens using infrared thermometry to estimate MST, and to study surface temperature variation of the wings, head, legs, back and comb as affected by air temperature and broiler age. One hundred Cobb® broilers were used in the experiment. Starting on day 7, 10 birds were weekly selected at random, housed in an environmental chamber and reared under three distinct temperatures (18, 25 and 32°C) to record their thermal profile using an infrared thermal camera. The recorded images were processed to estimate MST by selecting the whole area of the bird within the picture and comparing it with the values obtained using selected equations in literature, and to record the surface temperatures of the body parts. The MST estimated by infrared images were not statistically different (p > 0.05) from the values obtained by the equations. MST values significantly increased (p < 0.05) when the air temperature increased, but were not affected by bird age. However, age influenced the difference between MST and air temperature, which was highest on day 14. The technique of infrared thermal image analysis was useful to estimate the mean surface temperature of broiler chickens.
Motomiya A.V.A.,FCA UFGD |
Molin J.P.,University of Sao Paulo |
Motomiya W.R.,State University of Maringa |
Biscaro G.A.,FCA UFGD
Revista Brasileira de Engenharia Agricola e Ambiental | Year: 2012
This research aimed to evaluate the spectral response to variation of nitrogen levels and its relationship with leaf nitrogen, chlorophyll and yield in cotton crop. The experiment was conducted in Chapadão do Céu, MS, in a randomized block design with four replications. The treatments consisted of five N rates of 0, 30, 70, 110 and 150 kg ha-1, divided in two applications at 28 and 41 days after emergence, using urea fertilizer as a source. The highest correlations of the chlorophyll index and normalized difference vegetation index with yield were observed in the fourth observation, at 56 days after emergence, indicating that in this period, yield may already be compromised if there is shortage in the supply of N to the crop. The results obtained indicated that the sensor becomes more sensitive to variations of nitrogen levels as the crop grows, but not when it reaches a high leaf area index and in the begining of the senescence. It is concluded that ground level remote sensing permits to estimate indirectly the amount of N absorbed, chlorophyll index and cotton yield.