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Modificazioni indotte dalla defogliazione sul metaboloma delle uve Pinot nero e sulla composizione polifenolica dei vini
No full textComposizione chimica ed evoluzione del profilo aromatico di spumanti Ribolla gialla prodotti con diversi metodi di rifermentazione
No full textControlling microbial infection by managing grapevine canopy
No full textPinots (Vitis vinifera L.) are known as tight-clustered grape varieties, where the mechanical pressure of adjacent berries may disrupt cuticle waxes, thus predisposing these sites to greater incidences of infection. One of the main causes of crop quality degradation is grape rot due to
the development of various microorganisms (bacteria, yeasts or other fungi). Among them
Botrytis cinerea is one of the most frequent problems. Because mold spores are ubiquitous, the control of germination and growth in the vineyard by use of fungicides may only be part of the solution. Therefore, carefully selected cultural practices may play a significant role toward encouraging or discouraging mold and other microbial infections. A field trial was established in Pinot Noir vineyard of Vipava Valley for two consecutive years.
Preliminary results based on visual examination of microbial compromised grapes indicated that earlier leaf removal treatments reduced the extent of microbe damage on grape. Therefore in the following harvest three different treatments of leaf removal (at pre-flowering, berry-set
and veraison phase of grape development) were performed, using untreated vines as a control.
Temperature and humidity data were collected in the grape area of all treatments. Microbial population on grapes was followed using standard cultivation methods during ripening and at harvest time as well as visual inspection of damaged / sound grapes was performed at both times. At harvest time compactness of grapes was also evaluated. Parallel trial with excluding last Switch® application was done to evaluate the effect in different treatments. In general we observed the change in species composition on the surface of grapes with early
predominance by the basidiomycetous yeasts and species Aureobasidium pullulans, and at
harvest time with the prevalence of the ascomycetous yeasts, lactic / acetic acid bacteria and molds. Leaf removal was much more effective against Botrytis Cinerea compering to additional Switch® application, especially at leaf removals at earlier stages. Pre-flowering leaf removal also
showed significant reduction of grape compactness. The results suggesting early leaf removals as successful tool for reducing the risk of microbial infections
Pyranoanthocyanins formation in Pinot noir wines as affected by different timing of leaf removal performance in the vineyard
No full textABSTRACT - The profiles of many technologically important phenolic compounds in grapes can be significantly affected by the manipulation of grapevine canopy microclimate through leaf removal. However, due to global warming, too high berry surface temperatures after late canopy opening (at veraison as traditionally performed) can cause an inhibition of the synthesis in case of pigments responsible for the colour of red grapes and wines. When seeking for alternatives, particular care should be dedicated to the varieties known for its genetically derived poor anthocyanin potential, such as Pinot noir (V. vinifera L.).
Alternative earlier leaf removals (before flowering, at berry set) were performed in the field experiment in order to ascertain their influence on wine-colour related phenolics as compared with late leaf removal and untreated control. Furthermore, the grapes of all treatments were processed separately by typical Pinot noir winemaking techniques and the formation of more stable pigments - pyranoanthocyanins was monitored by means of UHPLC/TQ-MS in the must samples during fermentation, in young wines, and finally in the wines after four years of aging.
The results indicated earlier leaf removals, particularly pre-flowering leaf removal as a good solution within predicted global warming scenarios. Besides promoting several anthocyanins (mostly delphinidin and petunidin, both around 40%), total flavonols (75%) and slightly advancing hydroxycinnamates in grapes as compared to control, also the promotion of pyranoanthocyanins was noticed already during must fermentation. Even the improvements were rather small initially in the young wines, they showed an interesting progress during aging, demonstrating that not only colour intensity, but also Pinot noir wine colour stability could be improved by the implementation of more knowledge-based canopy microclimate manipulation
An analysis of the effects of water regime on grapevine canopy status using a UAV and a mobile robot
Full text linkIn this paper, we propose a novel approach for analyzing the effects of water regime on grapevine canopy status using robotics as an aid for monitoring and mapping. Data from an unmanned aerial vehicle (UAV) and a ground mobile robot are used to obtain multispectral images and multiple vegetation indexes, and the 3D reconstruction of the canopy, respectively. Unlike previous works, sixty vegetation indexes are computed precisely by using the projected area of the vineyard point cloud as a mask. Extensive experimental tests on repeated plots of Pinot gris vines show that the GDVI, PVI, and TGI vegetation indexes are positively correlated with the water potential: GDVI (R2=0.90 and 0.57 for the stem and pre-dawn water potential, respectively), PVI (R2=0.90 and 0.57), TGI (R2=0.87 and 0.77). Furthermore, the canopy volume and the canopy area projected on the ground are impacted by the water status, as well as stem and pre-dawn water potential measurements. The results obtained in this work demonstrate the feasibility of the proposed approach and the potential of robotic technologies, supporting precision viticulture
An investigation of vine water status as a major factor in the quality of Merlot wine produced in terraced and non-terraced vineyards in the Vipava Valley, Slovenia
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Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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