Developmental physiology Flashcards
Three aspects of Yield formation
- Cultivar and/or clone bud fruitfulness
- Bud load retained at winter pruning
- Shoot and/or cluster thinning
What is crop load and what is crop level?
- Crop load is a ratio of leaf area to yield
- Crop level is expressed as the number of clusters per vine
top is high capacity
bottom is high vigor
What is overcropping>
when we exceed the potential of the vine and there is not enough carbon to be partitioned
What is vine capacity?
a vine’s total weight of fruits and shoots at the end of season
What is vigor?
The rate of shoot growth (cm/day)
Grapevines have a limited capacity because of limitations imposed by available resources, so…
vines can only support a certain number of shoots and ripen a certain amount of fruits in any one season.
largest yield potential is often achieved on vines of…
Medium vigor
Low light on leaves above and below a bud reduces
bud fruitfullness
What is PAR and why is it important?
PAR is Photosynthetic Active Radiation. When PAR goes below 1/3 of maximum light availability there is a marked reduction in bud fruitfullness.
Severe loss of leaf area can reduce
inflorescence initiation and differentiation
In addition to high light, _____ are required for maximum inflorescence initiation and development
relatively high T
__________ reduces bud fruitfulness; a ___________ might increase it.
- Severe water stress
- moderate water stress
Both block 0 and 1 have low bud induction
Block 2 and 3 have higher bud induction
