1,721,128 research outputs found
Viticultural strategy to reduce alcohol levels in wine
No full textAbstract: Full-bodied and deeply colored red wines are presently the most appreciated and prized. Well-ripe grapes normally have a high glucidic content that gives highly alcoholic wines. Moreover, global temperature is increasing leading to advance in berry maturation and increase of sugar accumulation; this fact enhances even more the average wine alcohol content. Due to the consumer concern about the effects of high alcohol wine drinking, several producers have started to offer low alcohol wines. This type of wines can be produced by reducing alcohol in winery or by reducing sugar accumulation in berries. Within the last approach, different strategies have been suggested: selecting specific varieties or clones, increasing crop load, shading bunches, choosing proper irrigation techniques, modulating source-sink relationships by removing leaves or topping shoots, applying anti-transpirant to leaves or plant growth regulators to grapes. The results obtained from many studies are
not univocal and are likely affected by the interaction between genotype and environment and by the extent to which each technique is applied
Growing grapes under cover
No full textGrowing grapvine under cover allows to advance or delay the grape harvest. The final effects depends on the properties of type of plastic cover (more or less transparent to the incoming solar radiation and to the outcoming long infrared radiation), the time of cover setting (early or late in the grapevine annual biologicl cicle), the type of covering stucture (completely closed or laterally open), the vineyard management, the grape vriety and the environmental conditions. This paper refers about the main implications of this technique, as they result from trials carried out in Southern Italy
SCAMBI GASSOSI IN SEI COMBINAZIONI DI INNESTO DI VITE AD UVA DA VINO IN COLTURA ASCIUTTA ED IRRIGUA.
No full textLeaf water use efficiency in a 'tendone' trained canopy: a contribute to the ecophysiological characterization of a grapevine growing system
No full textall papers have been reviewed by expert
Shade nets on tablegrapes
Full text linkThe use of covering nets is widely diffused in horticulture in order to protect plants from adverse conditions such as hail, wind or light excess, pest attacks, bird injury, hence, several type of articles are available. Most of nets are transparent/whte, aiming at allowing light penetration, or also black or green when shading effect is desired. In the last decade, photo-selective colored nets have been also experimented in order to assess the effects that the change in light spectrum may exert on leaf functioning, shoot growth and
fruit quality. Nevertheless, all nets reduce the amount of light available for the crop; in many cases the leaf net photosynthetic rate is reduced, but, on the other hand, leaves and fruits are protected from damages caused by excess of irradiance. Besides decreasing incident solar radiation, nets modifies the crop microclimate in terms diurnal pattern of air
temperature and humidity; they may lower daytime temperature and vapor pressure deficit, but increase night temperature, enhancing atmospheric stability. Under semi-arid
conditions, to limit the solar irradiance at canopy level may be useful to lower the transpiration rate and thus the crop water deficit. Hence shade nets may be helpful to attenuate the effects of multiple environmental stresses. On table grapes, the net use of nets is quite largely diffused, but, on the whole, relatively little information is still available on their physiological effects on leaf functioning and grape quality. The most used net types reduce wind speed by 80-85%, and photosynthetic photon flux by 10-25% or even more, according to the net color. In many cases vine vigor and yield are increased; sometime, negative effects on berry characteristics have been noticed, such as a poorer skin color. To avoid possible detrimental effects, canopy management and other cultural practices should be adapted to match better the needs of vines grown under shade nets
- …
