Remote-Sensing (RS) is the most widely used technique for crop monitoring in precision viticulture systems. This paper considers the possibility of substituting RS information obtained by various proximal sensing technologies employed directly in vineyards in order to enable a simultaneous evaluation of canopy health and vigour status. To this aim, a mobile lab has been developed. It consists of (a) two GreenSeeker RT100 sensors, a commercial optical device calculating NDVI, and Red/NIR indices in real time; (b) three pairs of ultrasonic sensors to estimate canopy thickness; and (c) a DGPS receiver to geo-reference data collected while travelling in a vineyard. During the 2007-2008 campaign, tests were carried out in a commercial vineyard in order to evaluate the monitoring system performance regarding disease appearance, diffusion, and vegetative development variations due to the normal growing process of vines. Surveys with the mobile lab were conducted in two groups of rows, treated and untreated with agrochemicals, and compared to manual morphological and physiological observations that characterised the phytosanitary status of the canopy. Measurement repeatability was verified; both NDVI values and ultrasonic data showed high repeatability (with r = 0.88 and r = 0.85, respectively). Optical data were processed in order to obtain NDVI maps, which clearly showed differences in canopy vigour evolution in the two examined groups, with low vegetative vigour in areas infected by Plasmopara viticola, as confirmed by manual assessment. Maps of the percentage infection index (I%I) were produced according to pathological manual survey results. The comparison between I%I and NDVI maps qualitatively confirmed the real vine phytosanitary status. Ultrasonically measured canopy thickness (UCT) was calculated and compared to manually measured canopy thickness (MCT) (r = 0.78). UCT and NDVI values were compared in order to identify areas affected by disease among zones presenting critical vegetation conditions.
Background and Aims
The increasing interest by the wine market in sparkling white wines challenges how the desired grape composition can be achieved under the pressure of global warming. The aim of the present study was to assess the viability of summer pruning as a tool to pilot ripening towards desired compositional patterns.
Methods and Results
Ortrugo was subjected to basal leaf removal applied either at pre‐flowering (ELR) or in lag‐phase (LLR) and to bunch thinning (BT; removal of 50% of crop at lag‐phase) in comparison with untreated control (C). Treatments induced large variation in bunch mass (30% less in ELR vs BT), yield per vine (37 and 21% less in BT and ELR vs C) and total soluble solids at harvest (BT scored 2.9°Brix higher than that of C). Conversely, given the same harvest date, all practices failed to maintain titratable acidity (TA) at the threshold of 6.5 g/L.
Conclusions
The data suggest that crop regulation achieved in the high yielding Ortrugo, through either BT or ELR, increases sugar accumulation rate so that concurrent optimal TA level (≅6.5 g/L) can be easily achieved by slightly anticipating harvest date. Under conditions of thermal or light stress, or weather conducive to bunch rot, preference should be given to ELR.
Significance of the Study
Suitable summer pruning techniques might be used as flexible and powerful tools to direct ripening towards the desired crop composition.
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