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“Sunscreen” for Fruit

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Agnova Technologies in cooperation with the manufacturer Engelhard Corporation have released a revolutionary agricultural tool that reduces sunburn damage - a costly problem for Australian growers.

Trials across Australia show that coating apples, and other fruits, with Surround WP crop protectant manufactured by the Engelhard Corporation and distributed by Agnova, can reduce sunburn damage by as much as 73 percent. In that study, 73 percent damage reduction translates to a marketable yield increase of 34 percent.

Agricultural economists estimate that Australia’s ex farm-gate horticultural losses to sunburn may be as high as $200 million a year. The cost for many individual producers is substantial. Sunburn losses to the grower are due to discarding of sunburn fruit, increased picking and grading costs, and downgrading at the pack house.

For some apple varieties such as Granny Smith, it is common to lose 20 percent, or more, of production to sunburn damage. Complete crop loss in some crops can occur during times of extreme heat. Heat stress can also cause significant losses. Losses to heat stress can include: reduced size, fruit drop, reduced overall quality, reduced storage life, and reduced bloom the following season.

Plant surface protection

A proven method of sunburn control and heat reduction has been established with Surround crop protectant, from Engelhard Corporation. Engelhard calls the concept ‘Plant Surface Protection’. Sprayed onto crops, Surround forms a white protective film that shields plants from harmful solar radiation and intense heat.

Since 2000, growers in the United States and elsewhere have protected fruit crops by coating trees with Surround crop protectant.

U.S. growers protected more than 15,000 hectares of apples and pears with Surround in 2003.

Australian growers have successfully applied Surround for three seasons in some areas.

Growers in the Goulburn Valley have used Surround for plant surface protection on a range of apple varieties, including: Fuji, Gala, Granny Smith and Pink Lady.

Growers have also used it on ‘Autumn Giant’ plums and ‘Red Sensation’ pears.

During the 2003-04 season, growers used Surround in the Riverland of South Australia, south-western New

South Wales, Stanthorpe in Queensland, and the apple regions of Gippsland and Harcourt.

Surround delivered results in keeping with those of the previous 2 years’ trials.

Growers who have used Surround report other benefits including improved apple fruit colour – particularly in hard-to-colour apple varieties and on the blind side of the fruit.

This improvement in colouration results from increased scatter of light within the canopy caused by reflection from the leaves.

Other benefits can include a reduction in fruit cracking and less russeting.

In Queensland, Surround has also proven beneficial for pineapple growers.

These growers found Surround easy to mix and apply, and that it provided good management of sunburn in both processing and fresh market pineapples.

Protection you can see — performance you can trust.

Based on a specialized kaolin—a naturally occurring, inert white mineral Surround represents a breakthrough opportunity for plant surface protection called “Particle Film Technology.”

Particle film technology was co-developed by the United States Department of Agriculture (USDA) and Engelhard Corporation, the world leader in surface and materials science, through several years of development.

Engelhard formulation scientists have developed particle-based formulations that offer several important qualities, such as: reflectance of the sun’s heat; easy mixability in water; good coverage capacity; and good adherence to the plant canopy and fruit.

Surround is available in an easy-mixing wettable powder formulation as Surround WP crop protectant.

Mixed in water and sprayed onto the plant, the specially engineered kaolin particles in the Surround formulation link together in a loose particle film network. The particle film is porous so water and carbon dioxide can pass through. The stomata are not blocked, so the plant can respire normally.

Leading plant physiologists state that apple sunburn may occur whenever air temperatures in the orchard exceed 30 degrees C. Temperatures higher than 30 C also stress the tree.

Fruit losses from heat stress typically occur when the temperature increases rapidly and the fruit has not been acclimatized. Surround can lower apple skin temperatures by 6C to 8C+, while leaves are typically 3C to 5C cooler.

Usable light or photosynthetically active radiation (PAR) passes through the film but heat-producing infrared light and damaging ultraviolet rays are blocked. Reducing heat stress by lowering the leaf temperature can result in a net increase in photosynthesis - leading to improved tree health.

Healthier plants have high fruit carrying capacity.

Easy on the environment

The base mineral in Surround, kaolin, is used in cosmetics, toothpaste, and baby powder.

Kaolin is approved for use as a food additive—up to 2.5 percent by the US-FDA.

The Organic Materials Review Institute (OMRI) has listed Surround WP crop protectant for use in organic fruit production in the US.

Removing the Surround protectant film

Surround can be washed off harvested apples, pears, plums and nectarines with standard packing shed cleaning systems, including soak-tank, long brush bed and overhead pressure sprayers.

Waxing procedures also improve fruit appearance. Some pack house managers have found it beneficial to use warm water (28C) and soak fruit slightly longer than normal and/or to add an approved fruit washing detergent before brushing.

If some residue remains in the stem and calyx end of the fruit, waxing will render it essentially invisible. A pack house film removal test is required prior to its commercial use to ensure that the packing line can successfully remove all of the film.

Careful attention must be paid to the washing instructions on the product label before use.

Much more than apples

Protecting plant surfaces with a coating of Surround crop protectant has proven effective in reducing sunburn, sunscald, bleaching, russet, and heat stress in other tree crops such as pears, plums, nectarines, citrus, nuts, mangoes and other tropical fruit.

Surround can also be used on row crops such as pineapples, fresh and processing tomatoes, and cucurbits. Trials are in progress with Surround in a range of other crops, including wine grapes, olives and avocados. Plan ahead for sunburn and heat

As a planned treatment, the protection provided by Surround provides growers with the potential for a significant return on their investment. Moreover, economic analysis indicates that Surround can provide a good return on investment even in a low sunburn year.

For more information on how Surround can reduce sunburn in your crops, visit www.agnova.com.au or

contact Product Specialist David Bell, at +03 5831 5457 or +0417 501 503.

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