Abstract
Single leaf photosynthesis, whole vine photosynthesis measured in a whole plant chamber, dry matter partitioning, and several morphological indices were measured at four phenological stages of development on two-year-old, own-rooted Seyval grapevines adjusted to five different crop loads. Crop loads were 0, 1, 2, 4, or 6 clusters/vine with all laterals removed to eliminate intra-vine shading. Leaf area was inversely related to crop load, with differences evident as early as fruit set. Differences in dry weight partitioning did not become evident until mid-season. Leaf and shoot dry weight were inversely correlated, and fruit dry weight positively correlated with crop load, respectively. Root dry weight was inversely related to crop load only at harvest. Leaf area per vine, leaf size, shoot length, node number, and internode length were inversely related to crop load. Berries per cluster and cluster weight were inversely correlated with clusters per vine. Yield and berries per vine were correlated with clusters per vine. Sugar accumulation and shoot maturation were delayed by high crop loads. Implications of the crop load treatments on vine photosynthesis are discussed.
- crop load
- dry matter partitioning
- source-sink
- photosynthesis
- yield
- fruit composition
- morphology
- cane maturation
- Received February 1994.
- Copyright 1995 by the American Society for Enology and Viticulture
Sign in for ASEV members
ASEV Members, please sign in at ASEV to access the journal online.
Sign in for Institutional and Non-member Subscribers
Log in using your username and password
Pay Per Article - You may access this article (from the computer you are currently using) for 2 day for US$10.00
Regain Access - You can regain access to a recent Pay per Article purchase if your access period has not yet expired.