Francisco Mandelli

Alterações micrometeorológicas em vinhedos pelo uso de coberturas de plástico

The objective of this work was to evaluate the effects of plastic covering on the microclimate of vineyards (Vitis vinifera L., cultivar Moscato Giallo), in Serra Gaucha region in Rio Grande do Sul State, Brazil. The experiment was performed in Flores da Cunha, RS, during the 2005/2006 growing season. It comprised uncovered and covered rows of vines, using a 160 µm thick plastic film. Photossinthetically active radiation (PAR), air temperature and humidity, and wind velocity were monitored: over the plastic covering; between the film and the canopy; over the uncovered canopy; and close to grapes of both treatments. Reference evapotranspiration was estimated for both treatments. From the incoming PAR, 67.5% reached the covered canopy, 16% reached the covered grapes, and 36% reached the uncovered grapes. The plastic covering increased by 3.4oC the maximum air temperatures close to plants. Diurnal air relative humidity was reduced, while water vapor pressure and vapor pressure deficit were increased because of the plastic covering, which also reduced in 88% the wind velocity in comparison to open air. The reference evapotranspiration on the covered canopy was 35% lower than in open air. Although increasing diurnal air temperatures, the plastic covering may reduce the evaporative demand on vineyards, by reducing the incoming solar radiation and the wind velocity.

Microclima de vinhedos sob cultivo protegido

Microclimate alterations promoted by plastic covering over vineyards interfere in the plant physiology and fungal diseases incidence on grapevines. The aim of this research was to evaluate the influence of the plastic covering on the microclimate of vineyards, in particular on the quality of the incoming solar radiation. The experiment was carried out in 2005/06 and 2006/07 seasons in Flores da Cunha-RS, in a vineyard of Moscato Giallo cultivar shaped in Y, with impermeable plastic (160μm) over 12 rows of 35m length and five rows without covering (control). In both treatments the air temperature and humidity, incoming photosynthetically radiation and wind speed were measured at the level of the canopy and clusters. Continuing measurements were taken through sensors and automatic acquisition systems (datalogger). Influences of the covering on quality of the incoming solar radiation, from 300 to 750nm, were evaluated through a spectroradiometer. The impermeable plastic covering above the plant rows increased the air temperature and decreased the photosynthetically radiation and wind speed. The covering interfered on the quality of the incoming solar radiation, by reducing mainly the irradiance in the ultraviolet band and reducing also the ratio between the irradiance in the red and far-red bands.

Potencial produtivo de videiras cultivadas sob cobertura de plástico

The objective of this work was to evaluate the effect of plastic cover on the yield components of grapevine (Vitis vinifera L.) cultivar Moscato Giallo. The experiment was carried out in 2005/2006 and 2006/2007 crop seasons, in Flores da Cunha, RS, Brazil, in two vineyard areas, one covered with an impermeable plastic film and other without covering (control). The microclimate was evaluated in terms of air temperature, air relative humidity, photosynthetically active radiation and wind speed above canopy and close to clusters. The yield components were evaluated in a completely randomized design, in ten plants randomly selected in each area. Measures were made for production per plant, yield per hectare, clusters per vine, clusters per square meter, twigs per square meter, weight and length of clusters, weight of rachis, number of berries per cluster, diameter of berries, and skim/pulp ratio. Plastic cover promotes yield increases, does not affect pulp/skin ratio, and promotes production stability, independently of climate conditions in each season.

Efeito da poda verde na composição físico-química do mosto da uva Merlot

Grapevine canopy management can induce modifications in the grape and wine composition and quality, and summer pruning is among the cultural practices used to reach this objective. In this way, an experiment with different types of summer pruning were carried out to improve the quality of Merlot grape must. It was performed from 1993/1994 to 1996/1997 on a vineyard conducted in the pergola system. There were 12 treatments with three replications disposed in a randomized block design. Treatments consisted of control grapevines and 11 types of summer pruning, i.e., sprouting, topping and leaf removal, some of them applied in different times of the grapevine vegetative cycle. Results show that there was variation among years, but considering the average of the four vintages, the best treatments were 10 (sprouting + topping + leaf removal on the bloom time with removal of all leaves below clusters) and 9 (sprouting + leaf removal of half leaves below clusters 21 days before harvesting) proportioned higher synthesis and accumulation of sugar, expressed by oBrix and density, and lower of acidity, expressed by tartaric and malic acids, pH and titratable acidity. Following in effectiveness, the treatments 11 (sprouting + topping + leaf removal of half leaves below clusters 21 days before harvesting), 2 (topping) and 3 (leaf removal of all leaves below clusters in the bloom time).

Maturação da uva niágara rosada cultivada em estufa de plástico e a céu aberto

The objective of this work was to evaluate the effect of the plastic greenhouse on the maturation of Red Niagara (Vitis labrusca L.) grapevines. The experiment was carried out in Bento Goncalves, RS, Brazil, from July 1994 to January 1995. There were two cultural systems (greenhouse and natural condition) and three pruning times for each system (July 21 and August 1st and 11). The variables evaluated in the must were oBrix, density, pH, total acidity, and oBrix/total acidity. Grapevines cultivated in the greenhouse accelerated the process of maturation in all pruning times. Grape maturity was anticipated from 17 to 25 days (average of 21 days) when reached 15oBrix and from 20 to 33 days (average of 27 days) with 18oBrix, varying according to the pruning time. However, considering the greenhouse effect on both the grapevine phenology and the pruning time, grapevines early pruned showed an anticipation of harvest of 32 days when compared to the normal pruning time in the Serra Gaucha region. This anticipation of grape maturation could allow prices five times higher when harvested with 15oBrix than those obtained with grapes grown in the natural condition.

Relações hídricas, rendimento e compostos fenólicos de uvas Cabernet Sauvignon em três tipos de solo

No presente trabalho, foi avaliada a influencia de tres tipos de solo (Argissolo Bruno-acizentado, Planossolo Haplico e Neossolo Regolitico) sobre aspectos quantitativos e qualitativos da producao de uvas destinadas a vinificacao. O experimento foi executado no ciclo 2008/2009, em vinhedo da cultivar Cabernet Sauvignon (Vitis vinifera L.), no municipio de Bento Goncalves, (RS). Avaliou-se a disponibilidade hidrica em base gravimetrica ao longo do periodo de maturacao das uvas, o potencial da agua na folha, parâmetros de crescimento vegetativo, componentes do rendimento e os compostos fenolicos no momento da colheita. Argissolos Bruno-acizentados propiciaram maior crescimento vegetativo, sobretudo em massa de ramos, comprimento de entrenos e area foliar, assim como, cachos com maior numero de bagas. Planossolos Haplicos com maior disponibilidade hidrica proporcionaram maior produtividade das videiras. Neossolos Regoliticos levaram a menor disponibilidade hidrica, o que reflete em reducao do potencial da agua na folha. Nestas condicoes de restricao hidrica, as videiras tiveram menor crescimento e rendimento, como tambem, maiores teores de taninos e indice de polifenois totais. Em geral, o Neossolo Regolitico pode ser considerado mais promissor para a obtencao de vinhos finos de qualidade.

Manejo do dossel vegetativo da videira e seu efeito na composição do vinho Merlot

The objective of this work was to evaluate the effect of grapevine (Vitis vinifera L.) summer pruning on Merlot wine composition. An experiment was carried out from 1993/1994 to 1996/1997 in Bento Goncalves, RS, Brazil, using a control and 11 summer pruning in grapevines trained in pergola system. Principal component analysis showed that the summer pruning effects varied by year. Considering the average of the four years, the first three principal components were responsible for 72% of the total variation. Sprouting, topping, and removal of all leaves below grapevine clusters at the beginning of bloom had high values of color intensity, absorbances at 280 and 520 nm, anthocyanins, tannins, alcohol, 3-methyl-1-butanol/2-methyl-1-propanol, alcohol in weight/reduced dry extract, and phosphorus and was the best alternative for the production of quality Merlot wine.

Manejo do dossel vegetativo e seu efeito nos componentes de produção da videira Merlot

A poda verde e uma pratica cultural utilizada para melhorar as condicoes do dossel vegetativo dos vinhedos, visando a favorecer a qualidade da uva e do vinho. Nesse sentido, realizou-se este experimento entre as safras de 1993/1994 e 1996/1997, com diferentes modalidades de poda verde, num vinhedo do cv. Merlot conduzido em latada. Houve 12 tratamentos e tres repeticoes, sendo o delineamento experimental em blocos casualizados. Os tratamentos constituiram-se da testemunha e de 11 diferentes modalidades de poda verde, ou seja, desbrota, desponta e desfolha, algumas delas em diferentes epocas do ciclo vegetativo da videira. O componente principal 1, da analise de componentes principais (ACP) feita em cada ano, separadamente, mostra que o tratamento 10 (desbrota + desponta + desfolha realizada no inicio da floracao, eliminando-se as folhas abaixo dos cachos) discriminou-se nos quatro anos, e os tratamentos 7 (desfolha realizada 21 dias antes da colheita, eliminando-se metade das folhas abaixo dos cachos) e 6 (desfolha realizada 21 dias antes da colheita, eliminando-se as folhas abaixo dos cachos), em tres deles; a ACP da media dos quatro anos tambem evidencia essa discriminacao entre eles. Constata-se que o tratamento 10 foi um dos que tiveram intensidade de poda verde mais intensa, caracterizando-se por variaveis indicativas de plantas com vigor e produtividade mais baixos que os demais.