Fruit damage caused by high temperatures, UV light and solar radiation is a major concern but one that growers can easily manage.
In Australia, extreme heat events in horticultural production areas can be catastrophic resulting in reduced cropping plant function and placing plants in stress management mode rather than developing and ripening fruit.
Transpiration is the process by which plants maintain a flow of moisture through the plant. Moisture escapes through pores (stomata) in the lower surface of the leaf to maintain plant temperature.
Under heat stress conditions the plant is not able to maintain a consistent flow of moisture. When this occurs the stomata close and the cooling process stops, increasing the plants internal temperature which can damage plant cells.
Stress management
Under stressed conditions many normal plant functions slow or stop to prioritise the protection of plant tissue.
Photosynthesis and the production of carbohydrates, amino acids and proteins stops; affecting the development and ripening of fruit.
Two methods of heat stress management can be look at:
Minimise the exposure to temperature, UV light and solar radiation
Kaolin clay products can be used to minimise the exposure of leaves and fruit to heat stress.
Kaolin clay produces a protective film reducing the surface temperature of the plant by reflecting UV and solar radiation. The reflective properties also reduce the incidence of direct sun scald.
Reducing the plant temperature allows the plant to function and continue transpiration. By doing this, the plant can continue the cooling process and minimise sun damage.
Suncrops Plus
Suncrops Plus is a hydrated kaolin clay product that has been refined to produce a quality based product.
The product has two modes of action when dealing with heat stress.
- reflective properties of Kaolin
- organic compounds that activate the plant stress response.
Suncrops Plus should be applied as soon as the possibility of heat stress arises.
The product should be reapplied as the plant and fruit grow to maintain a protective film.
Suncrops Plus should also be reapplied if a significant rain event occurs.
Improve the plants ability to deal with the stress
Amino acids can be used to improve the plants ability to deal with stress events.
Amino acids are referred to as the building blocks of life and are essential to plant production. There are 20 essential amino acids for normal plant function, each amino acid has their own function and without them plants are unable to exist.
Amino acids can be applied before and after stress events. Applications before stress help the plant maintain plant function, while applications after the event reactivate the plant to minimise down time.
By keeping the plant active for longer during a heat event we can maintain the plant’s natural ability to cool itself.
Aminostim
Aminostim contains all plant essential amino acids in a unique formulation which is immediately available to the plant for stress relief.
Ninety per cent of the product is taken up within seven hours of application. This allows for immediate stress relief with the added benefit of the plant not having to expel energy to process the amino acids.
Aminostim should be applied before the stress event for best results and should be applied at 14 day intervals as the product has been proven to have an effect in plants for this period.
Contact Biogrow phone 03 8847 3888
e-mail
www.biogrow.com.au
For more information, see Tree Fruit Dec 2014
