Heat and light stress are economically important problems in agricultural production. Heat and light stress cause losses by reducing overall plant productivity and quality.
The most commonly observed symptoms are wilted or otherwise unhealthy looking plants and physical injury to limbs, leaves and fruit, generally referred to as sunburn.
Even if a plant looks healthy, heat and light stress can reduce or completely halt photosynthesis, leading to loss of productivity.
Water stress
Water stress is complex and is intricately involved with heat and light stress. Shortage of soil water can initiate and exacerbate heat and light stress.
When soil moisture is limiting, a plant’s ability to cool itself through transpiration is impaired—stomata are closed and leaf temperature increases. The photosynthetic machinery closes down and the plant is no longer able to process the light energy entering its cells.
This leads to photo-inhibition, a build-up of free radicals (oxidants) and ultimately to tissue destruction and cell death i.e. the symptoms of heat and light stress damage.
Heat stress
In the case where heat stress is initiated by high temperature, the plant will attempt to cool itself by means of increased transpiration.
Once the soil moisture becomes limiting the same sequence of-events as described above will take place.
Suncrops reduces heat stress & sunburn
Under high ambient temperatures, Suncrops reduces canopy temperature, reducing heat, light and water stress.
The reduction of stress results in increased fruit quality e.g. (TSS/Brix) and fruit size.
Other benefits include improved colour and reduced russet, fruit drop, sunburn and cracking.
Application
Best results are obtained from a season–long treatment program.
Apply to sunburn-prone fruit, leaf, limb and trunk surfaces before conditions leading to sun damage occur.
Apply the initial application at the full rate and a second at a half rate—at no more than a 10 day interval.
Subsequent applications may be made at the half rate (but do not reduce volume). Depending upon the length of the heat period. Repeat applications may be needed at intervals of 15 to 21 days.
General information
Suncrops has two modes of action for the protection of crop plants against abiotic stress.
The first is a visible particle film that reflects harmful UV and IR light, reducing the temperature of the plant.
The second is a naturally occurring compound, found in all crop plants, that triggers the innate stress response mechanism.
When Suncrops is applied to plants, a visible, grey film results. For best performance a thorough, uniform, and consistent coverage is essential throughout the stress period.
For information and product availability, contact inSense Pty Ltd phone 0407 366 526
e-mail
For more information, see Tree Fruit October 2013
