Wednesday, August 8, 2018
Sunday, August 5, 2018
Keep an Eye Out for Summer Limb Drop
As the afternoons here get hotter and more humid it is the well irrigated trees that can become a threat. Summer limb drop affects trees like the Floss silk tree, The Italian stone pine, and other susceptible varieties. Here is a news interview I did on the subject several years ago after some children were injured by a falling pine tree :
Friday, August 3, 2018
Wednesday, August 1, 2018
Beating the Heat Lecture: How to Protect Your Plants in Record Temps
BEATING THE HEAT
· July 6th -119 degrees F for over an hour
here.
Many Plants Scorched.
In the following days trees, shrubs and woody plants start to defoliate.
Many Plants Scorched.
In the following days trees, shrubs and woody plants start to defoliate.
The Physiology of Heat Damage
·
PWP -mostly a problem with herbaceous plants.
·
Chloroplast damage -sets off a chain reaction in the
plant.
o Increased
production of protective proteins
o Increased
production of abscission hormones.
o Increased
production of damaging peroxides.
·
Leaf drop
·
Fruit drop
·
Flower drop
·
Twig drop
·
Leaf scorch
·
Trunk and branch scorch (citrus and avocados)
·
Limb drop in susceptible trees.
What to Do After
·
Mulch
·
Increase irrigation frequency (but do not
overirrigate)
·
Do not fertilize
·
Do not overwater
What if More Heat is on the Way?
·
Anti-transpirants?
o Work by
either plugging up the stomata or causing it to close.
o Can cause
overheating, decrease transpiration.
o Work best
in frost situations
·
Misters
o Are
expensive
o Can cause
fungal infestations
o Require installation
and $
o Cheap
barrel misters may be the best bet.
·
Shade-cloth
o Can injure
plants if just ‘draped’ on.
o Should be
installed as a permanent structure.
o Need to
choose right % for the plant.
o Do not
prevent all heat damage.
·
Kaolin
o Sprays on
o Helps
control some insects as well
o Irrigation
washes it off.
o Looks
terrible.
·
Modify Irrigation
o Check
Evapotranspiration Index
o Water
according to current ET number.
§ Make sure
you do irrigation measurement before you do this.
o Use coffee
cups and turn irrigation on for 10 minutes, measure depth in inches.
·
Plant Choices
o Plants with
blue-green coating (glaucous) do well.
o Plants from
South Africa and Madagascar do well.
o Plants form
the Southwest, South and Central America (not all).
o Many (not
all) Australian plants.
o Plants from
temperate areas do not usually do well.
·
Landscape Choices
o Remember to
put heat and sun resistant plants near walls and walks.
o Go with
climate appropriate plants.
o Build shade
structures.
o Consider a
mist system (for you, not the plants).
Links:
- Scorch, Sunburn, and Heat Stress
- Plant tolerance to high temperature in a changing environment: scientific fundamentals and production of heat stress-tolerant crops
- When it is too hot for photosynthesis: heat-induced instability of photosynthesis in relation to respiratory burst, cell permeability changes and H2O2 formation
- Leaf scorch | The Morton Arboretum
- Sunburnt plants 'myth' is debunked - Telegraph
- leaf-scorch.pdf
- Extension Service | Leaf Scorch
- 8445.pdf
- Bacterial Scorch of Trees
- Leaf scorch | The Morton Arboretum
- Bacterial Leaf Scorch
- Homemade Whitewash for Trees
- Whitewashing an Avocado Tree
- UC IPM: UC Management Guidelines for Sunburn on Avocado
- Surround WP (25 Lb) - GrowOrganic.com
- Reserach-Summary_Cochran-Dissertation-MBI.pdf
- How to prune heat damaged foliage
- Impacts of Kaolin and Pinoline foliar application on growth, yield and water use efficiency of tomato (Solanum lycopersicum L.) grown under water deficit: A comparative study
- https://cimis.water.ca.gov/
Subscribe to:
Posts (Atom)