Download COMPO Sun Protect

Application recommendations
COMPO Sun Protect contains active ingredients which have to
be taken up by the plant surface and will be active after having
reached the target tissue. In most cases this process requires
up to 24 hours from the application time on. Thus it is strongly
recommended to spray COMPO Sun Protect at least 24 hours
before the expected high-radiation period. The higher level of
anti-oxidative agents in the crop tissue will last for about 7
to 10 days. After this period it will be necessary to repeat the
application.
Spraying should be done when there is a high probability for a
period of dry days with high solar irradiation during a sensitive
stage of the crop. This will never be completely predictable but
own observations or the local weather forecast will reduce the
risk of sunburn damages to a minimum.
COMPO Sun Protect – How does it work?
COMPO Sun Protect has been created to prevent fruits and
other susceptible plant parts from sunburn. It combines UV
absorbing compounds with the most effective natural antistress compound α-tocopherol. While α-tocopherol eliminates
ROS and stabilizes the cell membranes, special UV absorbers
prevent the radiation-induced destruction of cell structures.
COMPO Sun Protect
Boron is also added to COMPO Sun Protect because this micronutrient has proven to be very effective in enhancing the stress
tolerance of plants by stabilizing the cell wall and its function.
Furthermore boron plays a major role in regulating the permeability of cell membranes.
It is recommended to apply COMPO Sun Protect in a quantity of
1.2 liter solution per hectare. To ensure the ideal concentration
of the active ingredients 1.2 liter of COMPO Sun Protect should
be dissolved in 200 liters of water (= 0.6%).
For single plant treatments prepare also 0.6% solutions and
spray until the whole plant is wet.
Split applications at lower concentrations, for example two
times 0.6 liters per hectare at an interval of 5 to 7 days will
extend the effective time period.
COMPO Sun Protect
prevents valuable crops from sunburn due to its
physiologically active ingredients
saves the grower from significant yield losses
EXPERTS
FOR GROWTH
COMPO Sun Protect for
Fruit crops and grapevines: Less sunburn and more marketable fruits
Vegetables and ornamental crops: Better growth of young
plants after transplanting due higher stress tolerance
COMPO Sun Protect
Fig. 7: Synergistic action of the COMPO Sun Protect
ingredients in sunburn prevention
Prevents valuable fruits from sunburn
due to its physiologically active ingredients
Components:
COMPO Sun Protect is a borated
fertilizer.
Specific weight: 1.07 kg/l
pH: 7.3
Over-heating of tissues
α-tocopherol
Boron
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Saves the grower from quality yield losses
Stabilization of cell
membranes
Stabilization of the pectic network between the cell walls
Regulation of membrane
permeability
Cell damage induced by UV radiation
Phenolics acids
and UV absorbers
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Elimination of ROS and
radicals
Protection from radiation
Folder Sun 2012
α-DL-tocopherol
Phenolic acids
UV absorbers
Boron (2%)
Specific adjuvants to ensure uptake and enhanced
efficiency
Anti-oxidizing effects
Germany
COMPO GmbH & Co. KG
Gildenstraße 38
48157 Muenster
Phone: +49 (0) 251 3277-0
Fax: +49 (0) 251 326 225
e-mail: info@compo.de
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on the fruit variety and the local climate.
In growing regions with hot and dry summers, especially at
higher altitudes, the phenomenon of fruit sunburn is wellknown. Modern varieties like “Pink Lady” apples or “MD2”
pineapples are very susceptible to high solar irradiation and
rapidly loose their outstanding quality.
Fig. 1: Sunburn damage in pumpkin, grape and orange fruit
Both stress factors, heat and UV radiation, result in the formation of reactive oxygen species (ROS) and chemical radicals.
These species destroy cell membranes through oxidation (“oxidative stress”) and finally lead to cell death. Plants respond
to oxidative stress with the formation of antioxidants, which
eliminate ROS and radicals and prevent the cell membranes
from disintegration (figure 3). The most prominent antioxidants in plants are α-tocopherol (“Vitamin E”), ascorbic acid
(“Vitamin C”), carotenoids and phenolic compounds. Among
these compounds, α-tocopherol is the most effective natural
antioxidant: 1 molecule of α-tocopherol inactivates up to 220
radical molecules!
Fig. 3: Effect of oxidative stress and plant response
Oxidative stress
(Frost, Heat, Radiation, …)
Plant response:
Formation of ROS
.
(H2O2; O2 )
Formation of natural
antioxidants
Damage of cell membrane
Neutralization of free radicals
Fig. 2: Severe apple fruit damage due to sunburn, South Africa 2012
Loss of cell functionality
Preservation of cell functionality
Death of the cell
No damage
The major function of α-tocopherol is to keep the cell membranes functioning even under severe environmental stress
like over-heating. In this process α-tocopherol is working
Fig. 5: Significant increase of α-tocopherol concentration in “Elstar” fruit peels 24h after application of
COMPO Sun Protect
hand-in-hand with ascorbic acid. Whereas ascorbic acid is
mostly available in sufficient concentrations in the plant cell,
α-tocopherol is the limiting factor in the antioxidative defence
reaction.
0,8
Control
35
COMPO Sun Protect
30
When does sunburn damage occur?
Sunburn damage in fruits is supposed to be a consequence of
a) local overheating over the fruit skin and tissue and b) caused
by temporarily high UV radiation.
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20
15
10
5
0
On warm sunny days the fruit skin temperature may be 10 to
15°C above the ambient air temperature. This means 35°C
measured in the air temperature can easily result in an apple
skin temperature of 50°C or higher, which directly leads to local overheating and subsequently to skin lesions.
Beside air temperature UV radiation is able to damage plant
tissues. With every 1000 m increase in elevation there is a plus
of 10 to 12% more UV-A radiation on the ground. The share of
UV also increases with lower latitudes. Thus the most endangered zones are mountain regions at lower latitudes. UV radiation will be readily absorbed by the air humidity, therefore there
is a higher risk for UV damage during dry weather periods.
Injuries caused by tissue over-heating typically result in brown
or black sharp-edged spots on the fruit surface. This happens
easily when the fruit skin temperature exceeds 52°C for about
10 minutes. At lower temperatures (48°C) and in combination
with UV radiation the corresponding skin disorder will appear
more like a diffuse brownish area.
Fig. 6: Recovery of chlorophyll fluorescence in
Golden Delicious apple fruits after COMPO Sun
Protect application and exposition to UV light
(1.8 kJ/m2 for 14h)
0,5
0,4
0,3
0,2
0,1
Control - UV
Tab. 1: Sunburn damage in Golden Delicious fruits
after UV light exposition and treatment with COMPO
Sun Protect (1.8 kJ/m2 for 14h)
Control (no UV light)
0,6
0
24 h
Hours after application
Treatment
0,7
Chlorophyll-Fluorescence (Fv/Fm)
Sunlight is the driving force for growth and development of
green plants. In the process of photosynthesis solar energy is
transformed into carbohydrates, the basis for human nutrition.
However, in some cases sunlight induces severe damage of
plant tissues, especially in fruits. Nearly all kind of high-value
fruits are susceptible to light-induced skin damage: apples,
pears, peaches, citrus, pineapple and many more. Sunburncauses fruit yield losses in the range of 10 to 50%, dependent
What happens in the plant tissue when it is exposed to excessive high temperature
and UV radiation?
α-tocopherol (µg/g FM)
Sunburn damage in crop production
Sunburn rating*
(0-3)
0
Apples exposed to UV light
2.23
COMPO Sun Protect
1.26
COMPO Sun Protect
Control + UV
Tab. 2: Influence of COMPO Sun Protect treatments in
the field on sunburn incidence in „Granny Smith“
apples (South Africa)
Fruits with sunburn spots (%)
Treatment
none
low
medium
strong
Control
56.5
13.8
21.1
8.6
α-tocopherol (0.1%) +
ethylhexyl methoxycinnamate
96.3
3.7
0.0
0.0
* 0 = no, 1 = light, 2 = medium and 3 = severe damage
Fig. 4: Air Temperature (blue) and corresponding fruit surface temperature (red) in a pome granate orchard
Fruit Temp.
Air Temp.
Temperature (°C)
50
45
40
This graph illustrates the relationship between air temperature & fruit surface temperature. Note that fruit surface
temperature can be considerably higher than air temperature, and it is fruit surface temperature that determines the
level of sunburn.
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30
25
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10 11 12 Time
13 14 15
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Source: Yazici and Kaynak, 2006
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