Galileo Adeli Buriol

Clima e vegetação natural do estado do Rio Grande do Sul segundo o diagrama climático de Walter e Lieth

The natural vegetation in the State of Rio Grande do Sul was related to climatic availability through the climatic diagram of Walter and Lieth (1967). Values of mean monthly air temperature and rainfall from 41 meteorological stations during the period 1931-1960 were taken into account. For each meteorological station, a graph was plotted with months in the x axis and monthly air temperature and rainfall in the two y axis considering the y axis with rainfall two fold the y axis with air temperature. Results showed that Rio Grande do Sul as a whole fits in the zonobioma of warm humid temperate climate and forest vegetation. These results indicate the phytoclimate model of Walter and Lieth (1967) is not appropriate to represent the geographic distribution of the natural vegetation of the State, because this type of vegetation is not only that which covers the State that because it also parents praises.

Transmissividade a radiação solar do polietileno de baixa densidade utilizado em estufas

The transmissivity of the solar radiation by polyethylene cover used in plastic greenhouses was evaluated in the Central Region of the Rio Grande do Sul State, Brazil. The study was carried out inside a 10m x 25m greenhouse covered with low density transparent polyethylene with 100µm thickness, located at Federal University of Santa Maria. Incoming global solar radiation inside and outside was measured daily dunng July, 1991 to January, 1992. The effect of polyethylene cover on diffuse solar radiation was determined dunng 1993 year. The average transmissivity of global solar radiation was 56.2% early in the moming and 81.3% at near noonday. Diffuse solar radiation proportion was higher inside than outside the greenhouse and enhanced when water condenses on the inner surface of the film.

Comparação do crescimento e desenvolvimento da alface (Lactuca sativa L.) no interior e no exterior de uma estufa de polietileno em Santa Maria, RS

Growth and development of lettuce cultivar Brasil- 202, White Boston and Regina inside and outside of a polyethylene greenhouse were compared in Santa Maria, RS. During a winter period of 50 days the greenhouse caused an increase in about 256 degree-days in the temperature values above the base temperature for growth (estimated in 10°C). Mean soil temperature was also 5.3°C higher inside the greenhouse. The growth patterns of plants cultivated inside the greenhouse were similar to those cultivated outside. Growth parameters of leaf surface, shoot fresh weight, dry weight of leaves. stem and roots and the shoot/root ratio were lower outside the greenhouse. The number of leaves per plant was similar in both conditions. Brasil-202 showed earlier growth and higher dry matter accumulation. Protection of plants with polyethylene greenhouses is an efficient technique to improve lettuce crop production in winter.

Arranjos de plantas de mandioca e milho em cultivo solteiro e consorciado: crescimento, desenvolvimento e produtividade

The objective of this study was to quantify the growth, development, and yield of cassava and maize in different plant spacings in monocropping and intercropping systems, considering two sowing dates of maize. The experiment was carried out in Santa Maria, RS, Brazil. The cassava variety RS 13 was planted on September 27, 2005. The maize variety BRS Missoes was sown on two dates: November 2, 2005 and November 29, 2005. The experimental design was a complete randomized blocks with 12 treatments and three replications. Growth (plant height and leaf area), development (phyllochron, final leaf number and duration of developmental phases), and yield parameters of both crops were measured. Thermal accumulation (assuming a base temperature of 14 oC for cassava and 10 oC for maize) of some developmental phases and the phyllochron were calculated. Growth and development were not affected by plant spacing in both monocropping and intercropping. The highest land use efficiency was obtained by intercropping cassava and maize, with cassava planted in a double row spacing of 1.6 x 0.5 x 0.6 m and maize in a single row spaced 0.8 x 0.21m or two rows of maize spaced 0.4 x 0.42m between the double rows of cassava, with maize sown on cassava emergence.

Effect of polyethylene mulches on soil temperature and tomato yield in plastic greenhouse

Este experimento foi conduzido para avaliar o efeito da cobertura do solo com polietileno transparente, preto, branco e co-extruzado branco-preto sobre a temperatura do solo e produtividade do tomateiro no interior de uma estufa plastica, em Santa Maria, Rio Grande do Sul, Brasil. O periodo experimental foi de 21 de agosto a 02 de dezembro de 1994. Observou-se que a temperatura maxima e media diaria do solo foi maior sob polietileno transparente. A amplitude maxima da onda diaria de temperatura do solo foi maior nos materiais opacos em relacao ao transparente. Nao houve diferenca estatistica na produtividade do tomateiro entre os tratamentos, mas a produtividade media foi maior com plasticos opacos do que com o plastico transparente. Entre os plasticos opacos, a maior produtividade foi obtida nos plasticos brancos, que refletem maior fracao da radiacao solar global incidente do que o plastico preto.

Soil heating by solarization inside plastic greenhouse in Santa Maria, Rio Grande do Sul, Brazil

Abstract Solar heating of soil by mulching with transparent polyethylene (known as soil solarization) is a physical method of soil disinfestation. The increase in soil temperature by solarization inside a plastic greenhouse in Santa Maria, Rio Grande do Sul State, Brazil, was measured. It was estimated the time which soil temperature exceeded some thermal levels in solarized soil, During the 1992/1993 and 1993/1994 summers, experiments were carried out in a 10 m × 25 m plastic greenhouse. Soil temperature was measured at 2 cm, 5 cm, 10 cm, and 20 cm depths in one solarized and uncovered plot. An increase of 10°C or more was observed in solarized soil at 2 cm and 5 cm depths in comparison to the bare soil. Soil temperature exceeded 50°C or more several days during 1993/1994 up to the 10 cm depth. The estimated exposure time at several thermal levels in solarized soil allow to conclude that solarization presents potential in the region.

Disponibilidade de radiação solar nos meses de inverno para o cultivo do tomateiro (Lycopersicun esculentum Mill.) na região de Santa Maria, RS

The probability of occurence of days with solar radiation bellow the critica1 value for the development of tomato inside greenhouse in Santa Maria, Rio Grande do Sul State, were calculated during May, June, July and August. It was considered the flue density of solar radiation of 200cal cm-2 dia-1 as the lowest value to tomato growth and 180cal cm-2 dia-1 as the low value referente of solar radiation for crop growth. Daily values of solar radiation were estimated by sunshine duration during the time period from 1912 to 1996. Results showed that the availability of solar radiation in Santa Maria was lower than the required by tomato crop inside plastic greenhouse during Winter, mainly in June and July.

Variabilidade interdecadal na série secular de temperatura do ar em Santa Maria, RS

The objective of this work was to verify possible associations between the interdecadal variability of minimum (Tmin) and maximum (Tmax) daily air temperatures and daily thermal range (DTR) in Santa Maria, RS, Brazil, with the Pacific Decadal Oscillation (PDO). Daily Tmin and Tmax values, from January 1912 to December 2009, and the monthly values of the PDO index during the same period were used. There is association between the interdecadal variability of Tmin, Tmax, and DTR with the PDO in this location. There was a decrease in Tmin and Tmax, during the 1947-1976 cold phase of the PDO. In the two PDOs warm phases, 1925-1946 and 1977-1998, there was an increase in Tmin during the first period and in Tmax during the second period. There was a reduction in DTR during the 1947-1976 cold phase of the PDO, due to a reduction of average Tmax and maximum Tmax. There was an increase in DTR in the first semester during the current (1999-2009) cold phase of the PDO, due to a decrease in average Tmin. These warming and cooling cycles, on the decadal time scale, may help in defining adaptation and mitigating strategies in agriculture through plant breeding and the development of cultivars tolerant to such temperature oscillations.

Transpiração do tomateiro cultivado fora do solo em estufa plástica e sua relação com os elementos meteorológicos

Neste trabalho, foram determinadas as relacoes da transpiracao das plantas do tomateiro (Lycopersicon esculentum M.) cultivado em estufa plastica com os elementos meteorologicos. Realizaram-se tres experimentos, no Campo Experimental do Departamento de Fitotecnia da Universidade Federal de Santa Maria - UFSM (RS): no outono-inverno de 1997 e nas primaveras de 1997 e de 1998. Cada planta foi cultivada num volume de aproximadamente oito litros de substrato colocado em sacola plastica. Para a determinacao da transpiracao diaria, foi utilizado um sistema de lisimetros de drenagem, obtendo-se a transpiracao pela diferenca entre o volume de agua irrigado e drenado. A transpiracao das plantas foi correlacionada com os elementos meteorologicos radiacao solar global diaria e media diaria da temperatura, umidade relativa e deficit de saturacao do ar. Os modelos de regressao obtidos indicaram que e possivel estimar a transpiracao com razoavel acuracidade apenas na primavera. As melhores estimativas foram obtidas com o deficit de saturacao do ar em regressao simples (R2 = 0,814) e em regressao multipla com o deficit de saturacao do ar e a temperatura do ar (R2 = 0,881).

Água no solo e rendimento do trigo, soja e milho associados ao El Niño Oscilação Sul

The objective of this study was to simulate soil water content, and wheat, soybean and maize yields, in Santa Maria, RS, Brazil, and link their interannual variability to El Nino Southern Oscillation (ENSO). The period studied was 1969 to 2003. Soil water content and the yields of wheat, soybean and maize were simulated with models available in the literature. Soil water content was represented by the fraction of transpirable soil water. The results showed that the lowest soil water content in Santa Maria is associated to neutral years and the highest soil water is associated to El Nino events. La Nina years were more favorable to high wheat yield, whereas El Nino years were more favorable to high soybean and maize yields. It was evident that years classified as neutral years in respect to ENSO are riskier to grain yields of soybean and maize crops, which is an important information for planning strategies in agribusiness considering ENSO forecast.