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.
AlyM.El-MegeedN.A.AwadR.M.2010Reflective particle films affect on sunburn, yield, mineral composition and fruit maturity of ‘Anna’ apple (Malus domestica) treesRes. J. Agr. Biol. Sci.68492
D’AquinoS.D.CoccoA.OrtuS.SchirraM.2011Effects of kaolin-based particle film to control Ceratitis capitata (Diptera: Tephritidae) infestations and postharvest decay in citrus and stone fruitCrop Prot.3010791086
GarciaM.E.BerkettL.P.BradshawT.2003Does Surround have non-target impacts on New England orchards? In: Bramlage W. (ed.). Proc. New England Fruit Meetings 2002–2003. 108–109:35–39
GindabaJ.WandS.J.E.2005Comparative effects of evaporative cooling, kaolin particle film and shade net on sunburn and fruit quality in applesHortScience40592596
GlennD.M.2009Particle film mechanisms of action that reduce the effect of environmental stress in ‘Empire’ appleJ. Amer. Soc. Hort. Sci.134314321
GlennD.M.2010Canopy gas exchange and water use efficiency of ‘Empire’ apple in response to particle film, irrigation, and microclimatic factorsJ. Amer. Soc. Hort. Sci.1352532
GlennD.M.DrakeS.AbbottJ.A.PuterkaG.J.GundrumP.2005Season and cultivar influence the fruit quality response of apple cultivars to particle film treatmentsHortTechnology15249253
GlennD.M.ErezE.PuterkaG.J.GundrumP.2003Particle films affect carbon assimilation and yield in ‘Empire’ appleJ. Amer. Soc. Hort. Sci.128356362
GlennD.M.PradoE.ErezA.McFersonJ.PuterkaG.J.2002A reflective processed-kaolin particle film affects fruit temperature, radiation reflection and solar injury in appleJ. Amer. Soc. Hort. Sci.127188193
GlennD.M.PuterkaG.J.2007The use of plastic films and sprayable reflective particle films to increase light penetration in apple canopies and improve apple color and weightHortScience429196
GlennD.M.PuterkaG.J.DrakeS.R.UnruhT.R.KnightA.L.BaherleP.PradoE.BaugherT.A.2001Particle film application influences apple leaf physiology, fruit yield, and fruit qualityJ. Amer. Soc. Hort. Sci.126175181
GlennD.M.WünscheJ.McIvorI.NissenR.GeorgeA.2008Ultraviolet radiation effects on fruit surface respiration and chlorophyll fluorescenceJ. Hortic. Sci. Biotechnol.834350
JifonJ.L.SyvertsenJ.P.2003Kaolin particle film applications can increase photosynthesis and water use efficiency of ‘Ruby Red’ grapefruit leavesJ. Amer. Soc. Hort. Sci.128107112
JoubertP.H.GrovéT.De BeerM.S.SteynW.P.2004Evaluation of kaolin (SURROUND® WP) in an IPM program on mangoes in South AfricaActa Hort.645493499
LapointeS.L.MckenzieC.L.HallD.G.2006Reduced oviposition by Diaprepes abbreviatus (Coleoptera: Curculionidae) and growth enhancement of citrus by Surround particle filmJ. Econ. Entomol.99109116
Le GrangeM.WandS.J.E.TheronK.I.2004Effect of kaolin applications on apple fruit quality and gas exchange of apple leavesActa Hort.636545550
LeskeyT.C.WrightS.E.GlennD.M.PuterkaG.J.2010Effect of Surround WP on behavior and mortality of apple maggot (Diptera: Tephritidae)J. Econ. Entomol.103394401
MelgarejoP.MartinezJ.J.HernandezF.Martinez-FontR.BarrowsP.ErezA.2004Kaolin treatment to reduce pomegranate sunburnSci. Hort.100349353
PaceB.BoariF.CantoreV.LeoL.VanadiaS.De PalmaE.PhillipsN.2007Effect of particle film technology on temperature, yield and quality of processing tomatoActa Hort.758287293
PascualS.CobosG.SerisE.2010Effects of processed kaolin on pests and non-target arthropods in a Spanish olive groveJ. Pest Sci.83121133
RosatiA.MetcalfS.G.BuchnerR.P.FultonA.E.LampinenB.D.2007Effects of kaolin application on light absorption and distribution, radiation use efficiency and photosynthesis of almond and walnut canopiesAnn. Bot. (Lond.)99255263
SackettT.E.BuddleC.M.VincentC.2007Effects of kaolin on the composition of generalist predator assemblages and parasitism of Choristoneura rosaceana (Lep., Tortricidae) in apple orchardsJ. Appl. Entomol.131478485
SchuppJ.R.FallahiE.ChunI.J.2002Effect of particle film on fruit sunburn, maturity and quality of ‘Fuji’ and ‘Honeycrisp’ applesHortTechnology128790
WandS.J.E.TheronK.I.AckermanJ.MaraisS.J.S.2006Harvest and post-harvest apple fruit quality following applications of kaolin particle film in South African orchardsSci. Hort.107271276
WeerakkodyP.JoblingJ.MagdalenaM.InfanteV.RogersG.2010The effect of maturity, sunburn and the application of sunscreens on the internal and external qualities of pomegranate fruit grown in AustraliaSci. Hort.1245761