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Mossoró, Brazil

Dantas D.D.C.,UFERSA | de Medeiros J.F.,Rural University | Freire A.G.,Federal University of Ceara
Revista Ciencia Agronomica | Year: 2011

The need for techniques that increase the yield of melon with fruit in obtaining desirable traits by consumers, with high content of soluble solids and pulp firmness, good flavor and good external appearance, is a reality. The soil cover with polyethylene films is a technique that was introduced in the agro-pole Assu-Mossoró-Baraúna to meet this demand. The objective of this study was to evaluate the yield and fruit quality of yellow melon grown with four irrigation depths (L1 -100%, L2 - 91%, L3 - 82%, L4 - 72% of the standard depth of 452 mm which was determined by the methodology of the FAO Kc dual) and tree types of polyethylene film (white-black, silver-black, black-black) used for the soil cover, compared with cultivation without coverage. Was used the randomized block design with split plot into 4 × 4, and four replications. The use of polyethylene films provided a significant increase in yield, and the increase of fruit weight by 20% on average, compared to treatment without coverage; the polyethylene film of white-black and black-black were better in relation to the silver-black color; the standard depth of 452 mm can be reduced by 28% without yield reduction even with the average fruit weight decrease by 11%; the concentration of soluble solids decreased as the irrigation was reduced due to heavy pest attack. Source

Da Silva R.G.,UFERSA | Maia A.S.C.,Sao Paulo State University | de Macedo Costa L.L.,Federal Rural University of the Semiarid Region
International Journal of Biometeorology | Year: 2015

This paper presents a new thermal stress index for dairy cows in inter-tropical regions, with special mention to the semi-arid ones. Holstein cows were measured for rectal temperature (TR), respiratory rate (FR) and rates of heat exchange by convection (C), radiation (R), skin surface evaporation (ES) and respiratory evaporation (ER) in the north eastern region of Brazil, after exposure to sun for several hours. Average environmental measurements during the observations were air temperature (TA) 32.4 °C (24.4–38.9°), wind speed (U) 1.8 m.s−1 (0.01–11.0), relative humidity 63.6 % (36.8–81.5) and short-wave solar radiation 701.3 W m−2 (116–1,295). The effective radiant heat load (ERHL) was 838.5 ± 4.9 W m−2. Values for the atmospheric transmittance (τ) were also determined for tropical regions, in order to permit adequate estimates of the solar radiation. The average value was τ = 0.611 ± 0.004 for clear days with some small moving clouds, with a range of 0.32 to 0.91 in the day period from 1000 to 1300 hours. Observed τ values were higher (0.62–0.66) for locations near the seacoast and in those regions well-provided with green fields. Effects of month, location and time of the day were all statistically significant (P < 0.01). A total of 1,092 data were obtained for cows exposed for 1 to 8 h to sun during the day; in 7 months (February, March, April, July, August, September and November), 4 days per month on the average. A principal component analysis summarised the TR, FR, C, R, ES and ER measurements into just one synthetic variable (y1); several indexes were then obtained by multiple regression of y1 on the four environmental variables and its combinations, by using Origin 8.1 software (OriginLab Corp.). The chosen equation was the index of thermal stress for cows, ITSC = 77.1747 + 4.8327 TA − 34.8189 U + 1.111 U2 + 118.6981 PV − 14.7956 PV 2 − 0.1059 ERHL with r2 = 0.812. The correlations of ITSC with TR, FR, C, ES, R and ER were 0.275, 0.255, −0.493, −0.647, −0.818 and 0.075, respectively. Correlations of the index with the physiological variables are presented, and ITSC is compared to three other indexes. © 2014, ISB. Source

Torres S.B.,UFERSA | Pereira R.A.,Brazilian National Council for Scientific and Technological Development
Revista Brasileira de Sementes | Year: 2010

Electrical conductivity has been recommended for evaluating seed vigor in peas and other species although research is still needed to improve procedures. The objective of this study was to develop methodology for the electrical conductivity test to evaluate the physiological potential of salad rocket (Eruca sativa L.) seeds. Five seed lots were used for each of two cultivars of salad rocket, "Cultivada" and "Folha Larga". The following tests were made: standard germination, first germination count, accelerated ageing, field emergence and variations in the electrical conductivity test (25 or 50 seeds imbibed in 25 mL, 50 mL or 75 mL of water; at 20 °C, 25 °C and 30 °C; for 1, 2, 4, 8, 12, 16, 20 and 24 hours). The results confirmed the efficiency of the electrical conductivity test to evaluate salad rocket seed vigor. The best combination was 50 seeds immersed in 50 mL of deionized water at 25 °C, for eight hours. Source

A study was conducted aiming to determine the plants species poisoning of zootechnical interest in 35 cities from Central and West regions of Rio Grande do Norte state, Brazil. It was interviewed 180 farmers, 20 veterinarians, 12 agriculture experts, and 5 agronomists. Data obtained in the interviews were compiled and analyzed using the software Epi Info version 6.04. The plant species responsible by greater number of poisoning outbreaks were Ipomoea asarifolia, Aspidosperma pyrifolium, Indigofera suffruticosa, Manihot carthaginensis subsp. glaziovii, Amorimia septentrionalis, Tephrosia cinerea, Anadenanthera colubrina var. cebil, Marsdenia megalantha, Anacardium occidentale, Cnidoscolus quercifolius, Crotalaria retusa, Froelichia humboldtiana, Ipomoea carnea, Leucaena leucocephala, Manihot esculenta, Mimosa tenuiflora, Nerium oleander, Prosopis juliflora, Ricinus communis, Sorghum bicolor, Sorghum halepense, and Urochloa (Brachiaria) decumbens. Source

Do Carmo B.B.T.,UFERSA | Pontes R.L.J.,UFC Virtual Institute
International Journal of Engineering Education | Year: 2013

The development of the Internet has led to a great transformation in different spheres of society, including education. The question discussed in this research is not whether this transformation is positive or negative. This study aims to discuss the potentialities of Web 2.0 tools in education, observing how it can be used in Engineering Education models. The question that we want to help answer is: How can engineering professors use Web 2.0 tools, for example in a blog, in teaching strategies to create a motivational learning space? A methodology based on collaborative learning was proposed to students in the Industrial Engineering Fundamentals discipline using Web 2.0 tools to evaluate its potential to aid autonomous learning. It was concluded that Web 2.0 tools have a large potential in Engineering Education. This methodology created a space in which students have a more active role in the learning process. © 2013 TEMPUS Publications. Source

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