Mitigation Part B Flashcards
Techniques based on calibrated source limitation (3)
❖ Post-veraison apical leaf removal ❖ Use of shading nets
❖ Application of anti-transpirants
This is the reason why if we want to apply a source limitation….
We need to focus on the median and apical leaves, this is because they are younger and more efficient
If we decrease transpiration we are inhibiting the
cooling mechanisms of the leaf
Basal leaves, which are older have less
Photosynthetic potential
We can see that after veraison the apical part of the shoot is retaining the highest photosynthetic potential
Here we are opening a window about 50-60 cm tall above the cluster zone. The purpose is to get a calibrated source limitation, removing a fraction of the younger leaves, which are more photosynthetic efficient
This is another technique we can applying to aim calibrated source limitation, what is is and how do we use it?
use of anti-traspirant, a chemical compound with an active ingredient called Pinolene. We us it to reduce transpiration, but at the same time photosynthesis.
What is the week point of using Pinolene?
The weak point is that plant cooling defence is reduced if the transpiration is limited, so this technique is not recommended in a hot warm environment due to possible over-heating occurring.
From the tables showing the use of Pinolene we can see a reduction in _____ which was to be expected, but we can also see a reduction in ___________ that is unwanted
- Sugars
- Anthocyanins
What is Kaolin?
an inactive neutral white clay.
How is Kaolin used and what kinds are grapes are best suited for its use?
It acts on the reflectance property of the leaf, so higher amount of light is reflected and lower heating in those specific organs occurs. This can be used to fight sunburn and is well suited to varieties with very compact clusters.
Why it is well suited for berries with compact clusters?
Because compact clusters are able to get very hot in that they dont have any air circulation to cool them down
Also color and phenolics were definitely lower in the treatment having no kaolin and the positive effect of Kaolin on colour is related to___________.
less degradation of anthocyanins due to temperature.
What is another option for canopy cooling?
What are the two considerations that we have with these?
Shading nets
- White nets catch about 10% radiation
- Black nets catch about 50%
What is a growth regulator?
They are synthetic compounds and are able to interact with plant hormones, modifying the action, inhibiting the action, or promoting the action of endogenous hormones.
