Dry leaf hyperspectral reflectance predicts leaf elemental composition in grafted hybrids

The above-ground parts of plants, which constitute the phyllosphere, have long been considered devoid of bacteria and fungi, at least in their internal tissues and microbial presence there was long considered a sign of disease. However, recent studies have shown that plants harbour complex bacterial communities, the so-called “microbiome”[1]. We are only beginning to unravel the origin of these bacterial plant inhabitants, their community structure and their roles, which in analogy to the gut microbiome, are likely to be of essential nature. Among their multifaceted metabolic possibilities, bacteria have been recently demonstrated to emit a wide range of volatile organic compounds (VOCs), which can greatly impact the growth and development of both the plant and its disease-causing agents.

Context and purpose of the study. Climate change is a major challenge in wine production. It results in erratic weather conditions which may lead to a reduction in grape yield and the subsequent grape and wine quality.

The chemistry of wine is particularly complex due to biochemical and chemical interactions that significantly modify its organoleptic characteristics and stability over time. Aging on lees is a well-known practice during which various compounds are released, ensuring wines oxidative stability and its overall sensory quality [1,2].

One of the consequences of global warming is the quick berry development giving rise to a disconnection between sugar accumulation and the formation of important quality minor compounds such as phenolics and volatile compounds being a huge challenge for the oenologist [1]. Thus, this phenomenon is forcing the search on strategies for maintaining the quality of wines despite this situation. One possibility is to make an early harvest with a low sugar concentration (18ºbrix) and advanced harvest for sparkling wine (20-21ºbrix) and afterwards to combine base wines properly and carry out the second fermentation trying to compensate the lack of secondary metabolites due to the quick berry development and higher alcohol degree of the second one, not adequate itself for sparkling wine. The aim of this study was to assess the chemical and physical characteristics, mainly volatile profile, and foaming properties of sparkling wines from grapes of Chardonnay and Sauvignon blanc.

I risultati delle ricerche condotte in un vigneto sperimentale di Marsala (TP), scelto per omogeneità di fattori bio-agronomici (età, tecniche colturali, potenzialità vegetativa e produttiva)