Climate protection based on increased humus amounts in vineyard soils: sensor-based analysis of grapevine vitality

Grapevine vitality can be measured by various phenotypic parameter of which leaf chlorophyll content (LCC) is the most prominent indicator of plant stress and vice versa of plant vitality. While analytical methods for chlorophyll extraction are labour intensive, time consuming, and destructive, sensor-based tools represent a fast, flexible, and non-destructive alternative. However, when using a new sensor its reliability needs to be examined. Therefore, LCC predicted by the Dualex 4 Scientific sensor was compared with the absolute chlorophyll content used as ground truth, which were gained from analytical chlorophyll extraction from different grapevine cultivars. For this validation data set, a high correlation was observed making the sensor reliable for practical application. The Dualex was then applied for the evaluation of ‘Calardis Musqué’ vines grown on different organic amendments (biochar compost substrate and greenwaste compost) in the field around flowering in the growing season 2020. Significant differences in LCC could be found between three phenological stages (BBCH 57-69) for all plants with grapevines grown in control rows (without any organic amendment) always having lowest LCC. Thus, in this preliminary study the deep incorporation of organic amendments in vineyard subsoils seems to have beneficial effects on the chlorophyll content.