Kaolin-based particle films can reduce insect, heat, PAR, and ultraviolet stress in horticultural crops because of their ability to modify the microenvironment of the plant canopy as a result of the reflective nature of the particles. Particle films with a residue density of 1 to 4 g·m−2 leaf area have been evaluated in a range of crops and agricultural environments. The particle film is a general insect repellant resulting from the change in the plant’s leaf/fruit texture but also because it changes the reflected light signature of the plant causing insect avoidance for many pests. A general review of particle film effects on insect pests and insect predators is presented in Glenn and Puterka (2005). Other key papers include: D’Aquino et al. (2011), Joubert et al. (2004), Lapointe et al. (2006), Leskey et al. (2010), Pascual et al. (2010), and Sackett et al. (2007).
The alteration of reflected light is the result of the ability of the particle film to reflect IR, PAR, and ultraviolet radiation (Glenn et al., 2002, 2008; Steiman et al., 2007). Reflection of IR can reduce canopy temperature as much as 5 °C, which will reduce potential transpiration (Glenn, 2009; Glenn et al., 2003; Jifon and Syvertsen, 2003); however, reducing canopy temperature can reduce heat stress and increase water use resulting in reduced water use efficiency and increased productivity (Glenn, 2010).
The reduction of PAR by the film at the leaf level is compensated in varying degrees by diffusion of PAR into the interior of the canopy (Glenn and Puterka, 2007; Rosati et al., 2007; Wünsche et al., 2004). Whole canopy photosynthesis can be increased by the combination of reduced canopy temperature and increased interior canopy light (Glenn, 2009, 2010; Glenn et al., 2003).
In apple, reducing fruit surface temperature, PAR, and ultraviolet is an effective means of reducing sunburn damage in apple (Aly et al., 2010; Glenn et al., 2002, 2008; LeGrange et al., 2004; Wand et al., 2006) and other specialty crops including pomegranate (Melgarejo et al., 2004; Weerakkody et al., 2010) and tomato (Pace et al., 2007; Saavedra et al., 2006).
The particle film can improve apple fruit color in some regions (Aly et al., 2010; Garcia et al., 2003; Glenn, 2009; Glenn and Puterka, 2007; Glenn et al., 2001, 2005; Wand et al., 2006). However, there are instances of reduced apple color development (Gindaba and Wand, 2005; Schupp et al., 2002).
The use of a reflective particle film is effective in mitigating environmental stress and has significant economic benefits in agricultural crops. Glenn (2009) demonstrated in a 10-year study that fruit mass of kaolin-treated apples was greater than the untreated fruit in 9 of 10 years and that the magnitude of the treatment response increased with increasing growing season temperature (Fig. 1). These data suggest that growing season temperatures above 20 °C can potentially reduce fruit size, but the use of the reflective particle film can mitigate that effect. Management tools, including kaolin-based particle films, will be needed to mitigate increasing growing season temperatures associated with global climate change.
Aly, M., El-Megeed, N.A. & Awad, R.M. 2010 Reflective particle films affect on sunburn, yield, mineral composition and fruit maturity of ‘Anna’ apple (Malus domestica) trees Res. J. Agr. Biol. Sci. 6 84 92
D’Aquino, S.D., Cocco, A., Ortu, S. & Schirra, M. 2011 Effects of kaolin-based particle film to control Ceratitis capitata (Diptera: Tephritidae) infestations and postharvest decay in citrus and stone fruit Crop Prot. 30 1079 1086
Garcia, M.E., Berkett, L.P. & Bradshaw, T. 2003 Does Surround have non-target impacts on New England orchards? In: Bramlage, W. (ed.). Proc. New England Fruit Meetings 2002–2003. 108–109:35–39
Gindaba, J. & Wand, S.J.E. 2005 Comparative effects of evaporative cooling, kaolin particle film and shade net on sunburn and fruit quality in apples HortScience 40 592 596
Glenn, D.M. 2009 Particle film mechanisms of action that reduce the effect of environmental stress in ‘Empire’ apple J. Amer. Soc. Hort. Sci. 134 314 321
Glenn, D.M. 2010 Canopy gas exchange and water use efficiency of ‘Empire’ apple in response to particle film, irrigation, and microclimatic factors J. Amer. Soc. Hort. Sci. 135 25 32
Glenn, D.M., Drake, S., Abbott, J.A., Puterka, G.J. & Gundrum, P. 2005 Season and cultivar influence the fruit quality response of apple cultivars to particle film treatments HortTechnology 15 249 253
Glenn, D.M., Erez, E., Puterka, G.J. & Gundrum, P. 2003 Particle films affect carbon assimilation and yield in ‘Empire’ apple J. Amer. Soc. Hort. Sci. 128 356 362
Glenn, D.M., Prado, E., Erez, A., McFerson, J. & Puterka, G.J. 2002 A reflective processed-kaolin particle film affects fruit temperature, radiation reflection and solar injury in apple J. Amer. Soc. Hort. Sci. 127 188 193
Glenn, D.M. & Puterka, G.J. 2007 The use of plastic films and sprayable reflective particle films to increase light penetration in apple canopies and improve apple color and weight HortScience 42 91 96
Glenn, D.M., Puterka, G.J., Drake, S.R., Unruh, T.R., Knight, A.L., Baherle, P., Prado, E. & Baugher, T.A. 2001 Particle film application influences apple leaf physiology, fruit yield, and fruit quality J. Amer. Soc. Hort. Sci. 126 175 181
Glenn, D.M., Wünsche, J., McIvor, I., Nissen, R. & George, A. 2008 Ultraviolet radiation effects on fruit surface respiration and chlorophyll fluorescence J. Hortic. Sci. Biotechnol. 83 43 50
Jifon, J.L. & Syvertsen, J.P. 2003 Kaolin particle film applications can increase photosynthesis and water use efficiency of ‘Ruby Red’ grapefruit leaves J. Amer. Soc. Hort. Sci. 128 107 112
Joubert, P.H., Grové, T., De Beer, M.S. & Steyn, W.P. 2004 Evaluation of kaolin (SURROUND® WP) in an IPM program on mangoes in South Africa Acta Hort. 645 493 499
Lapointe, S.L., Mckenzie, C.L. & Hall, D.G. 2006 Reduced oviposition by Diaprepes abbreviatus (Coleoptera: Curculionidae) and growth enhancement of citrus by Surround particle film J. Econ. Entomol. 99 109 116
Le Grange, M., Wand, S.J.E. & Theron, K.I. 2004 Effect of kaolin applications on apple fruit quality and gas exchange of apple leaves Acta Hort. 636 545 550
Leskey, T.C., Wright, S.E., Glenn, D.M. & Puterka, G.J. 2010 Effect of Surround WP on behavior and mortality of apple maggot (Diptera: Tephritidae) J. Econ. Entomol. 103 394 401
Melgarejo, P., Martinez, J.J., Hernandez, F., Martinez-Font, R., Barrows, P. & Erez, A. 2004 Kaolin treatment to reduce pomegranate sunburn Sci. Hort. 100 349 353
Pace, B., Boari, F., Cantore, V., Leo, L., Vanadia, S., De Palma, E. & Phillips, N. 2007 Effect of particle film technology on temperature, yield and quality of processing tomato Acta Hort. 758 287 293
Pascual, S., Cobos, G. & Seris, E. 2010 Effects of processed kaolin on pests and non-target arthropods in a Spanish olive grove J. Pest Sci. 83 121 133
Rosati, A., Metcalf, S.G., Buchner, R.P., Fulton, A.E. & Lampinen, B.D. 2007 Effects of kaolin application on light absorption and distribution, radiation use efficiency and photosynthesis of almond and walnut canopies Ann. Bot. (Lond.) 99 255 263
Sackett, T.E., Buddle, C.M. & Vincent, C. 2007 Effects of kaolin on the composition of generalist predator assemblages and parasitism of Choristoneura rosaceana (Lep., Tortricidae) in apple orchards J. Appl. Entomol. 131 478 485
Schupp, J.R., Fallahi, E. & Chun, I.J. 2002 Effect of particle film on fruit sunburn, maturity and quality of ‘Fuji’ and ‘Honeycrisp’ apples HortTechnology 12 87 90
Steiman, S.R., Bittenbender, H.C. & Idol, T.W. 2007 Analysis of kaolin particle film use and its application on coffee HortScience 42 1605 1608
Wand, S.J.E., Theron, K.I., Ackerman, J. & Marais, S.J.S. 2006 Harvest and post-harvest apple fruit quality following applications of kaolin particle film in South African orchards Sci. Hort. 107 271 276
Weerakkody, P., Jobling, J., Magdalena, M., Infante, V. & Rogers, G. 2010 The effect of maturity, sunburn and the application of sunscreens on the internal and external qualities of pomegranate fruit grown in Australia Sci. Hort. 124 57 61