Submitted to: Acta Horticulturae
Publication Type: Proceedings
Publication Acceptance Date: 7/23/2010
Publication Date: N/A
Technical Abstract: Our goal is to select an improved, loose-clustered clone of Vignoles that will contribute to an integrated approach to disease control. Clonal selection has historically proven useful in reducing cluster compactness through a variety of mechanisms, including decreased berry size, lengthening of the rachis, and decreased fertility. Because Vignoles is a recent variety (developed in the 1930’s), sufficient clonal variation for selection has not accumulated, so we have used radiation to induce mutations in a set of 2306 Vignoles clones. We aim to decrease fertility slightly, reducing fruit set, thereby producing looser clusters, the mechanism by which the table grape Loose Perlette was developed by Olmo. Because Vignoles is already a low yielding variety, it will be essential to adjust overall crop load to offset decreased yield of individual bunches. An improved Loose Vignoles clone would preserve the unique and desirable sensory characteristics that distinguish Vignoles, but would produce higher quality fruit due to decreased bunch rot. The population of possible clones was generated by exposure of dormant buds to a radiation dose of 10 Gy or 20 Gy. Individual treated buds and untreated control buds were bench grafted to rootstock 3309C and planted at a vineyard spacing of 4 feet between vines and 9 feet between rows. A pyramidal selection approach for cluster compactness is being followed using berries per cm as a measure of cluster compactness.