ISHS Acta Horticulturae 379: International Symposium on Quality of Fruit and Vegetables: Influence of Pre- and Post- Harvest Factors and Technology
INVESTIGATION ON FACTORS AFFECTING EARLY DROPPING IN DOLCETTO (VITIS VINIFERA L.) |
| Authors: | R. Botta, R. Vallania, G. Me, A. Luzzati, N. Siragusa |
| Keywords: | grapevine, physiology, abscission, leaf analysis, fertilization |
| Abstract:
Early dropping of berries in the cultivar Dolcetto is a disorder that occurs in some locations in Piemonte (Italy) at a variable rate, according to year. The disorder is associated with the breakage of vascular bundles at berry abscission zone and results in dropping or in incomplete ripening of the berries. Although the selection of non-dropping mutants from plants obtained by  radiation treatment demonstrated the importance of the genotype to the disorder expression, a study has been carried out to investigate the influence of pedoclimatic and nutritional factors on berry dropping.
From 1987 to 1992, the observations were done in Vicoforte (CN) on dropping and non-dropping mutated plants, and in Chieri (TO), the second location being not affected by berry dropping, analysing soil, leaves (sampled at berry set and veraison) and fruit.
Concerning the climatic course of the considered years, Vicoforte resulted more rainy than Chieri.
From soil tests, Chieri texture was classified as clay loam, while Vicoforte as loam.
Both soils had alkaline pH (8–8.2) and lime was 28% and 12% in Chieri and Vicoforte soils, respectively.
Data on leaf analysis were compared with standard values from literature.
From leaf analysis emerged a quite low K content in all the samples and particulary in Vicoforte ones at veraison, when Mg was found higher than normal.
In Vicoforte, the resulting K/Mg rate was very low at veraison both in dropping and non-dropping mutants.
Musts from non-dropping mutants and from grapevines in Chieri had higher sugar content and lower titratable acidity than those from dropping plants in Vicoforte.
The main nutritional differences between vineyards in
| |
Download Adobe Acrobat Reader (free software to read PDF files) | |
