Particle Film Technology in Agriculture to Reduce Heat Stress

and Suppress Disease

Michael Glenn

Soil Scientist

Reflective surfaces are common plant adaptation

• Plants use pubescence and cuticular waxes to reduce environmental stresses

• Particle film technology builds on this strategy of a reflective plant surface

Particle Film of processed kaolin on the surface of an apple leaf

Particle Film on the underside of an apple leaf. The stomates are not blocked.

Particle film materials can be applied with conventional spray equipment. Film development

requires multiple applications

• First Spray

• Second Spray

• Third Spray

The reflective, particle film reduces the temperature of fruit and leaves

by reflecting infrared radiation (heat)

• The apple on the left has a particle film,

the apple on the right is untreated.

• This is an infrared image of the temperatures of the two fruit. The untreated fruit has a severe hot spot developing but the particle film treated fruit is much cooler

Reducing the heat load on fruit reduces sunburn

damage and increases net dollar return to the grower

Whole tree photosynthesis is measured with clear, mylar chambers.

• Studies demonstrate that the application of a particle film increases:

– Photosynthesis – Fruit size – Red color

Surround-WP reduced fruit cracking in ‘Stayman’ apple

• Untreated had 32% cracking • Particle film treated had 22%cracking

• A 10 % reduction in cracking results in $100’s of dollars in net return to the grower

Control

Conventional

Surround WP

Lime Sulfur +Wettable Sulfur

Surround WP + Lime Sulfur + Wettable Sulfur

Particle film materials together with sulfur

minerals provide excellent suppression

of apple scab and powdery mildew

Surround WP, wettable sulfur and

lime sulfur are listed as “organically

approved”

apple scab apple scab

powdery mildewpowdery mildew

Particle film materials control Fabraea Leafspot in pear

The tree in the foreground is defoliated by Fabraea leafspot disease

Implications of Particle Film Technology in Tree Fruit Production

• Reduced sunburn and fruit cracking

• Increased crop loads

• Improved fruit quality

• Multi-functional role of horticultural benefits as well as disease control

• High degree of insect suppression (See Dr. Puterka’s web site)