Kaolin-based Particle Film Research Articles

The Advantages of Using Kaolin-Based Particle Films to Improve Coffee Production in the Minas Gerais Cerrado Biome

Climate change, such as increases in atmospheric air temperature, threatens Brazilian coffee production, which is mainly carried out on small rural properties in a family farming model. Increases in air temperature causes heat stress to the plants, resulting in physiological damage. This work studied the application of processed kaolinite-based particle films (PKPF) as part of environmentally sustainable agricultural practices. This innovative technology aims to increase the productivity of coffee grown in full sunlight and evaluate the interest of coffee growers in incorporating this input in the management of crops as an alternative to the traditional model of increasing production through the expansion of cultivated areas. This is a review of the state of the art of the use of PKPF in coffee, and a descriptive and exploratory research, supported by a literature review and field data collected, through a structured questionnaire applied to a group of coffee producers from the Cerrado in Minas Gerais. The concept of environmentally sustainable coffee production is latent among coffee growers, who adopt practical actions to respect and preserve the environment during the production process. Increases in productivity are related to the adoption of technological innovations such as the use of PKPF in the management of plantations, being a viable alternative to increasing the plantation areas, and thus reducing native vegetation.

Effect of surround WP (a Kaolin-based particle film) on Ceratitis capitata infestation, quality and postharvest behavior of cactus pear fruit cv Gialla

• Medfly can cause high preharvest and postharvest losses to cactus pear • Preharvest kaolin treatments effectively prevented medfly damage • Kaolin treatments reduced postharvest losses from decay caused by fungi or bacteria • Kaolin did not negatively affect the ripening process of cactus pear • Kaolin increased the postharvest level of betaxantins and polyphenols in cactus pear A Kaolin-particle film (Surround WP) was applied at 3% to cactus pear (Opuntia ficus-indica cv Gialla) to assess its capacity to Control medfly (Ceratitis capitata Wiedemann) infestation and to evaluate its effects on the quality and postharvest behavior of treated fruit. In the first trial, Kaolin was applied at the end of July when fruit were green and about two weeks later, at color breakage. Its efficacy was compared with a standard organophosphate insecticide (Phosmet). The experiment was conducted in two locations in 2014 and 2015. Kaolin application was very effective in preventing medfly attacks until natural fruit drop in November. Kaolin treated fruit were harvested at the commercial maturity stage and stored 2 weeks at 8 °C plus 1 week at 20 °C, or 3 weeks at 2 °C plus 1 week at 20 °C. The incidence of decay in the presence of medfly larvae or only due to molds was 2 -13%. Phosmet was ineffective in preventing medfly attacks. The second study of Kaolin on fruit quality and postharvest behavior demonstrated that Kaolin slightly delayed fruit coloration when fruit was once or twice before harvest. Respiratory activity, ethylene rates, juice chemical composition and color at harvest time and after 1 or 2 weeks of storage at 8 °C plus 4 d at 20 °C demonstrated slight differences between Control fruit and Kaolin. Vitamin C, betaxantins levels and the antioxidant capacity of Kaolin treatments were lower or not different than Control fruit at harvest but increased at a higher rate than in Control fruit over storage. Total phenols decreased in all treatments during storage but at a slower rate in Kaolin treatments. Overall results show that Kaolin treatments are effective to prevent medfly attacks in cactus pears with no negative effect on fruit quality and shelf life.

Effect of applying a calcined kaolin-based particle film on the photosynthetic capacity and growth of young eucalyptus plants

In scenarios of climatic change when increased global temperatures can be expected, it is essential to search for technologies that favor sapling survival and growth after planting and increase yield in the field. Kaolin-based particle films (KBPF) have been applied as barriers against the deleterious effects of high levels of solar radiation. The objective of the present study was to assess the effects of applying purified calcined kaolin-based particle film to young eucalyptus plants. Five treatments were carried out: 0% (just water), 3%, 5%, 7%, and 10% calcined kaolin applied to the adaxial part of the leaves. A complete randomized block design was used with five treatments and ten replicates. The plants were assessed for height, diameter at ground level, gas exchanges (net photosynthetic CO2 assimilation, stomatal conductance and transpiration), instantaneous (WUE) and intrinsic water use efficiency (IWUE), chlorophyll a fluorescence (maximum quantum yield of photosystem II (PSII) (Fv/Fm), concentration of active reaction centers in relation to the quantity of photons absorbed (RC/ABS) and the maximum ratio of quantum yields of photochemical and concurrent non-photochemical processes in PSII (Fv/F0), SPAD reading and leaf ontogeny. The 3% KBPF concentration showed the best responses in biometric assessments 80 days after planting (DAP) and were corroborated by the responses of the leaf, stem and shoot dry matter production as a whole. The leaf ontogeny assessments showed positive responses following KBPF application when considering leaf development, with 7% KBPF concentration resulting in the highest mean values. The mean specific leaf mass had negative response to high KBPF concentrations. At 60 DAP, the gas exchange variables during both assessment periods declined with an increase in KBPF concentration. Significant differences as a result of KBPF applications were found only at the start of the assessments (34 DAP) for both WUE and for IWUE. Leaf ‘greenness’ (SPAD reading) at 47 days showed a quadratic relationship in both periods. The variables of chlorophyll fluorescence showed a linear response at 34 DAP and a quadratic response 60 DAP. KBPF application increased height and diameter growth in plants treated with 3% KBPF but this response was not associated with photochemical efficiency and photosynthetic carbon assimilation values on a single-leaf basis. The best performance among the variables was provided by 3% KBPF application.

Kaolin Reduces ABA Biosynthesis Through the Inhibition of Neoxanthin Synthesis in Grapevines Under Water Deficit.

In many viticulture regions, multiple summer stresses are occurring with increased frequency and severity because of warming trends. Kaolin-based particle film technology is a technique that can mitigate the negative effects of intense and/or prolonged drought on grapevine physiology. Although a primary mechanism of action of kaolin is the increase of radiation reflection, some indirect effects are the protection of canopy functionality and faster stress recovery by abscisic acid (ABA) regulation. The physiological mechanism underlying the kaolin regulation of canopy functionality under water deficit is still poorly understood. In a dry-down experiment carried out on grapevines, at the peak of stress and when control vines zeroed whole-canopy net CO2 exchange rates/leaf area (NCER/LA), kaolin-treated vines maintained positive NCER/LA (~2 µmol m−2 s−1) and canopy transpiration (E) (0.57 µmol m−2 s−1). Kaolin-coated leaves had a higher violaxanthin (Vx) + antheraxanthin (Ax) + zeaxanthin (Zx) pool and a significantly lower neoxanthin (Nx) content (VAZ) when water deficit became severe. At the peak of water shortage, leaf ABA suddenly increased by 4-fold in control vines, whereas in kaolin-coated leaves the variation of ABA content was limited. Overall, kaolin prevented the biosynthesis of ABA by avoiding the deviation of the VAZ epoxidation/de-epoxidation cycle into the ABA precursor (i.e., Nx) biosynthetic direction. The preservation of the active VAZ cycle and transpiration led to an improved dissipation of exceeding electrons, explaining the higher resilience of canopy functionality expressed by canopies sprayed by kaolin. These results point out the interaction of kaolin with the regulation of the VAZ cycle and the active mechanism of stomatal conductance regulation.

Effects of kaolin-based particle film on physiological, nutritional, nutraceuticals parameters and Ceratitis capitata infestations in peach fruit at harvest and after storage

The Mediterranean fruit fly (Ceratitis capitata Wiedemann) is a worldwide pest of economi importance because attacks a large number of agricultural crops and for the extent of the damage it causes. Among the alternative control strategies to the use of sprays with synthetic insecticides, a very important role can be played by powders obtained from rocks whose activity arise from the ability to form a film of white powder, which acts as a repellent and irritant to insects. This film can also interfere with plants’ physiology and affect quality of fruit. In this study the efficacy of a commercial kaolin-based formulation to control medfly infestations was compared to synthetic insecticides commonly used against this pest (phosmet, alfa-cypermethrin, deltamethrin). The results showed a significant reduction of medfly attacks in fruits treated with insecticides (1.5% damaged fruit) or with kaolin (0.5% damaged fruits) compared to the untreated sample (10% damaged fruits), while physiological and quality parameters ded not show relevant differences between treatments and control fruit. Overall results highlight how the use of kaolin represents a valid alternative to treatments with synthetic insecticides to control C. Capitata attacks on peaches, while not affecting fruits’ quality.

Production and quality of eucalyptus mini-cuttings using kaolin-based particle films

Considering the expansion of forest plantations over the Brazilian territory and the imminent increase in air temperatures due to global warming, the search for technologies that ensure high levels of productivity and high quality plants in clonal nurseries is essential. Applying kaolin-based particle films (KBPF) has been used as a physical barrier to reduce the negative effects of excessive solar radiation and adverse temperatures. The effects of KBPF on production and physiological quality of eucalyptus mini-cuttings were evaluated during two different seasons. A randomized block design was used, consisting of five treatments and four replications. Five concentrations (0, 3%, 5%, 7%, and 10%) were tested here and six weekly replicates of each concentration was applied. The different kaolin concentrations and seasonal variations resulted in a quadratic response of the leaf SPAD reading during both daily evaluation periods. KBPF applications resulted in a quadratic response of photochemical efficiency in the morning period, and an increasing specific leaf weight linear response, and during the dry season, the different kaolin concentrations resulted in a bud length quadratic response. The results indicated that the kaolin application maintained the production and yield index statistically equal between weekly KBPF applications, improving photochemical efficiency, leaf thickness, SPAD reading, and bud length. The use of KBPF could reduce the intervals between collections of mini-cuttings and increase nursery yields in environments that present high temperatures.

Kaolin-based particle film sprays reduce the incidence of pests, diseases and storage disorders and improve postharvest quality of ‘Delicious’ apples

Several pests and diseases infest apple during production, potentially causing heavy losses. Numerous pesticides are used to control pests and diseases, sprays of which contaminate the environment and result in pesticide residues. Among Good Agricultural Practices (GAPs), particle film technology (PFT) is promising for organic fruit production. Now some kaolin-based PFs such as Surround WP®, EclipseT, Anti-stress-500®, Parasol® have been developed which are available worldwide for commercial use. In India, preliminary research work was conducted for observing the effect of one kaolin-based PF (Surround WP®) on ‘Delicious’ apple. Five sprays of Surround WP® (3%) were applied to 20-randomly selected ‘Delicious’ apple trees each year during 2015–16 and 2016–17. The sprays were applied, starting on June 15 every year at fortnightly intervals and 20 unsprayed trees served as controls. Surround WP® reduced the incidence of San Jose scale (by ~ 64%), apple scab (by ~ 87%) and powdery mildew (by ~78%) significantly but increased the incidence of woolly apple aphid (by ~ 23%) compared to the control. Surround WP®- treated apples developed a better red color (Hunter ‘a’ value = 53.42 ± 0.42), increased anthocyanin content and improved appearance score. Surround WP® - treated apples were 35.4% firmer and contained a 49.9% higher Ca content compared to untreated fruit. Surround WP® treatment also showed significant improvement in soluble solids (increased by 10.5%) and ascorbic acid content (increased by 10.8%) with significant reduction in storage disorders such as bitter pit (reduced by 90.8%), brown core (reduced by 73.3%) and water core (reduced by 88.4%). Based on this study, Surround WP® can be recommended for organic production of ‘Delicious’ apples in Himachal Pradesh, India.

Effect of Surround WP®, a kaolin-based particle film on sunburn, fruit cracking and postharvest quality of ‘Kandhari’ pomegranates

Pomegranate (Punica granatum L.) can suffer from sunburn and fruit cracking, and biotic stresses such as bacterial blight (Xanthomonas axonopodis pv. Punicae) (Hingorani and Singh) Dye and fruit borer (Deuodorix isocrates Fabr.). Because particle film technology has emerged as a promising technology, many kaolin-based films such as Surround WP®, Parasol® and Anti-stress-500®, have been developed. Hence, a study was conducted to observe the effects of Surround WP® on ‘Kandhari’ pomegranate. For this, five sprays of Surround WP® (3%) were made during the fruiting season of 2015 and 2016 in randomly selected ‘Kandhari’ pomegranate bushes, starting from June 15, at fortnightly interval every year, in addition to non-sprayed control pomegranate bushes. Observations on biotic, abiotic stresses and quality attributes were recorded after harvesting fruit. The results revealed that pre-harvest sprays of Surround WP® reduced the sunburn and fruit cracking in ‘Kandhari’ pomegranates by 47% and 46%, respectively, and the incidence of both fruit borer and bacterial blight by 50.3 and 40.2%, respectively. The Surround WP®-treated pomegranates exhibited 46.4% higher cosmetic appeal, developed 19.5% higher red colour, and contained 17.4% higher levels of total anthocyanin content than untreated (control) fruit. Similarly, Surround WP®- treated fruit had significantly higher total phenolic content, antioxidant activity, higher juice recovery (18.2%) and soluble solid content (5.6%) but exhibited nearly 35.9% lower lipoxygenase activity than untreated pomegranates. Thus, this technology has potential to be adopted in pomegranate production.

Effects of kaolin on gas exchange, yield and head atrophy of artichoke,Cynara cardunculusL. subsp.scolymus(L.) Hayek

Environmental stress, as high air temperature and low relative humidity, increases the evaporative demand of the atmosphere, drives the sap flow mainly towards the leaves and causes a calcium deficiency in the artichoke heads that often promotes the formation of atrophic heads. The hypothesis is that conditions leading to a reduction of leaf temperature and transpiration can contribute to reduce the Ca deficiency-related disorders. Therefore, the use of kaolin-based particle film could be an effective tool as antitranspirant, thus mitigating detrimental effect of high evaporative demand that leads to the head atrophy. This study has investigated the effects of kaolin on gas exchange, yield and head atrophy of artichoke 'Violetto di Provenza', during June 2009-May 2010 in field conditions (southern Italy). The following treatments were compared: control without kaolin (C); kaolin sprayed plants starting 60 days (K1) and 67 days (K2) after the awakening. Kaolin, overall, at leaf scale caused the reduction, respectively by 10.3 and 23.8% in assimilation rate and transpiration, which led to 17.9% increase in photosynthetic water use efficiency. The production of marketable heads and atrophic heads not changed with kaolin application. The atrophic heads, all produced in the first three harvests, were 1,635 and 1,346 ha-1, respectively in C and K treatments, corresponding to 51.0 and 44.1% of total yield obtained in the same harvests. This does not exclude that kaolin can reduce heads atrophy, since the excessive earliness in artichoke awakening (mid-June), might have placed the crop in extreme climatic conditions, not sufficiently 'mitigated' from kaolin. Less extreme climatic conditions, which normally occur by awakening the artichoke later, could instead be mitigated by kaolin. Therefore, it would be useful to repeat the trial by scheduling artichoke awakening in different periods.

Effect of highly processed calcined kaolin residues on apple productivity and quality

Calcined kaolin-based particle films (PKPF) are effective in reducing insect, heat, photosynthetically active radiation (PAR) and ultraviolet radiation (UV) stress in plants due to the reflective nature of the heat-treated particles. The purpose of this study was to determine the effects of PKFP treatments applied at moderate (3%) and high rates (12% w/v) on apple physiology, yield and quality and the interaction with ambient ozone levels for a 6 year period. Fruit mass was increased by applications of PKPF at 3% and 12% in 4 of 6 years in non-irrigated treatments and in 2 of 6 years in irrigated treatments. Red fruit color was increased (lower hue angle) over the control in 5 of 6 years and in 2 of 5 years the 12% PKPF had improved red color over both the 0% and 3% PKPF non-irrigated treatments. PAR interception over 6 years, adjusted for LAI, was greatest for the control, least for the 12% PKPF, and 3% PKPF was intermediate. Reduced PAR interception below the canopy was likely due to greater PAR reflection within the canopy. Whole canopy temperature was significantly higher for the control (26°C) and lower for the 3% and 12% PKPF treatments (24°C). Fruit mass increased in the PKPF treatments, relative to the irrigated control treatment (%), with increasing maximum ozone levels during May. In laboratory studies, ozone degradation was greatest for alfalfa, least for calcined kaolin and the addition of alfalfa to calcined kaolin increased degradation proportionately. The present study confirms that calcined kaolin is an effective catalyst for ozone degradation and organic materials, such as alfalfa, are even more effective, due to the direct reaction with carbon molecules. Whole canopy gas exchange measurements (1000–1600HR) over a 10 day period in 2011 indicated that the 2.7% PKPF+0.3% alfalfa dust consistently had higher photosynthesis, 0.3% alfalfa was intermediate, while the control and 3% PKPF had the lowest photosynthesis rate. Whole canopy ozone degradation indicated that the 2.7% PKPF+0.3% alfalfa dust consistently had the greatest ozone degradation, 3% PKPF and 0.3% alfalfa were intermediate and the untreated control had the least ozone degradation. There is evidence that the 0.3% alfalfa stimulated a small amount of microbial growth on the leaf surface while the 2.7% PKPF+0.3% alfalfa stimulated a much greater amount of microbial growth. This synergistic effect may be due to the increased surface area in the particle film providing habitat for microbial populations and the reflection of UV by the particles that can be deleterious to microbial growth within that habitat. Data support the concept that chronic ozone damage is moderated to a significant degree by the use of surface treatments that catalyze ozone degradation in a particle film. The use of PKPF may be one tool to mitigate not only increased ozone stress but also heat stress from increased growing season temperatures in the future.

Effects of kaolin-based particle film and fruit zone netting on Cabernet Sauvignon grapevine physiology and fruit quality

<p style="text-align: justify;"><strong>Aims</strong>: Long exposure to high temperatures or UV-radiation may induce negative effects on vine physiology and grape composition. Here, the effects of two methods to moderate radiation and temperature in the fruit zone of a Cabernet Sauvignon vineyard were evaluated against a control.</p><p style="text-align: justify;"><strong>Methods and results</strong>: The treatments assessed were: (a) periodical spraying of kaolin on leaves and bunches and (b) fruit zone netting with a Raschell’s type mesh. The kaolin-based treatment increased the reflectance of light and moderately reduced fruit temperature (~1ºC below the control), whilst the shading net caused a significant reduction in radiation and temperature in the fruit zone (~7ºC below the control). The Net treatment showed lower (more negative) stem water potential values than the control, but did not persist until the end of the trial. Also, none of the treatments led to significant changes in stomatal conductance, transpiration or CO<sub>2</sub> assimilation throughout the season. However, the incidence and severity of fruit dehydration was significantly lower in the treated plants compared to the control. Finally, no differences in fruit chemical composition were observed between the treatments and the control.</p><p style="text-align: justify;"><strong>Conclusion</strong>: Under the conditions of this trial, both treatments tested were sufficient in moderating the negative effects of excess radiation or high temperature on grape berries.</p><strong>Significance and impact of the study</strong>: Kaolin-based particle spraying and fruit zone netting were proved to be feasible practical alternatives to lessen the negative effects of excess radiation or high temperature on grape berries, under hot climate.

Kaolin influences tomato response to salinity: physiological aspects

Environmental stress as salinity can negatively affect the physiology of tomato plants. Conditions leading to a reduction of transpiration can contribute to greater tolerance to salinity. Use of kaolin-based particle film technology (PFT) may be an effective tool to control stomatal conductance and transpiration rate, thus mitigating the detrimental effect of salinity. The present three-year study has investigated the effects of kaolin application on leaf gas exchange, leaf water potential, leaf and canopy temperature of field-grown tomato, irrigated with brackish water by drip method, in southern Italy. Treatments were: (1) three salinity levels of irrigation water (electrical conductivity of water = 0.5, 5 and 10 dS m−1); (2) tomato plants treated or not with kaolin; and (3) two cultivars in each year. The increase in salinity caused the reduction of leaf water potential, stomatal conductance, net photosynthesis and transpiration rate, and the increase of leaf and canopy temperature. Kaolin has resulted in an improvement of leaf water potential, and the reduction in gas exchange variables in low-salinity conditions. Under high salinity, kaolin was effective in limiting the reductions in net photosynthesis and reducing leaf and canopy temperature. These latter variables were slightly affected by kaolin, in different ways in respect to the saline treatments; while in non-saline conditions were 0.2–0.5°C higher in the kaolin-treated plants, the situation was reversed in more saline treatment. The variation of leaf and canopy temperature shows that kaolin influences the thermal balance mainly for the dual effect of reflection of the incident radiation and partial occlusion of the stomata. Kaolin mitigated detrimental effects of salinity also on yield, contributing to the improvement of income for the farmers. The use of kaolin-based PFT may be an effective tool to alleviate salinity stress in tomato production under arid and semi-arid conditions.

The Mechanisms of Plant Stress Mitigation by Kaolin-based Particle Films and Applications in Horticultural and Agricultural Crops

Kaolin-based particle films have use in reducing insect, heat, photosynthetically active radiation (PAR), and ultraviolet radiation stress in plants resulting from the reflective nature of the particles. Particle films with a residue density of 1 to 4 g·m−2 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. The alteration of reflected light is the result of the ability of the particle film to reflect infrared (IR), PAR, and ultraviolet radiation. Reflection of IR can reduce canopy temperature as much as 5 °C, which will reduce potential transpiration. 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. Whole canopy photosynthesis can be increased by the combined particle film effects of reduced canopy temperature and increased diffusion of PAR into the interior of the canopy. In apple, reducing fruit surface temperature, PAR, and ultraviolet is an effective means of reducing sunburn damage. The use of a reflective particle film is effective in mitigating environmental stress and has significant economic benefits in agricultural crops.

Kaolin potential for the integrated management of Aphis gossypii Glov. (Homoptera: Aphididae) on cotton

Kaolin-based particle film has been developed in the United States for use in agriculture as crop protectant. This work is aimed to determine the optimal kaolin concentration for use against Aphis gossypii, the most damaging sucking insect of cotton in Benin, West Africa. Following kaolin concentrations have been tested in four different experiments: 2%, 3%, 4%, 5%, 6% and 8%. The effect of kaolin is tested by recording the population dynamics of A. gossypii on cotton after spraying. Results showed that the solution containing 5% of kaolin has significantly reduced aphids' number. This concentration corresponds to a maximum of 18 kg of kaolin per hectare for the entire season when ultra low volume sprayer is used. Higher kaolin concentrations have left a large deposit of kaolin particle on cotton leaves thus handicapping chlorophyll synthesis and the proper growth and development of the plants. To obtain encouraging results, an adequate application method that provides a full and continuous coverage of the plants with kaolin particle film should be used. We suggest conducting trials on this product in practical cotton production conditions in West Africa to assess its potentiality as integrated pest management (IPM) component.

Effects of kaolin-based particle film to control Ceratitis capitata (Diptera: Tephritidae) infestations and postharvest decay in citrus and stone fruit

Ceratitis capitata (Wiedemann) is a major pest of fruit crops due to its wide host range and distribution. The objectives of this study were to evaluate the effectiveness of Surround WP, a kaolin-based particle film, as an alternative to synthetic insecticides to control medfly infestations and postharvest decay in citrus and stone fruit. No-choice, choice and half-choice laboratory experiments with citrus fruit, nectarines and peaches showed a significant reduction of medfly punctures and landings on kaolin-treated fruit. The total loss at harvest in satsumas sprayed with Surround WP (17%) was significantly lower than in those untreated (57%) or treated with trichlorfon (68%). In 2004, the yield loss at harvest in peaches and nectarines treated with Surround WP was not different compared to fruit sprayed with fenthion and trichlorfon, while in 2005 Surround WP was significantly more effective than insecticides in reducing the incidence of damaged fruit. Citrus and stone fruit treated with Surround WP showed a lower incidence of postharvest decay than control and insecticide-treated fruit. The present study shows for the first time the lower incidence of postharvest decay in fruit protected with Surround WP, which represents a suitable alternative to conventional insecticides in integrated and traditionally managed orchards.

Volatile Compounds and Sensory Attributes of Wine from Cv. Merlot (Vitis vinifera L.) Grown under Differential Levels of Water Deficit with or without a Kaolin-Based, Foliar Reflectant Particle Film

The volatile composition and sensory attributes of Merlot wines produced from vines under differing levels of water stress, with or without a foliar, kaolin-based particle film, were analyzed by stir bar sorptive extraction-gas chromatography-mass spectrometry (SBSE-GC-MS) and sensory evaluation. Vines were irrigated over consecutive vintages with 100, 70, or 35% of their estimated water requirements (ET(c)), or 35% until color change then 70% until harvest (35-70% ET(c)). Neither of the treatments consistently influenced ester concentrations or their relative amounts, though their concentrations varied from year to year. However, deficit irrigation had an effect on the concentration of terpene alcohols and norisoprenoids. Wines produced from vines under water deficit contained higher amounts of citronellol, nerol, geraniol, and β-damascenone, but linalool and β-ionone were not affected by deficit irrigation. Particle film did not affect volatile composition in the wine. Untrained panelists in 2007 and 2008 distinguished between wines from vines that received 100 or 35% ET(c) and between wines from vines that received 35 or 35-70% ET(c). Trained sensory panelists detected differences among wines for aroma, flavor, taste, and mouthfeel; however, significant interactive effects between particle film application and vine water status hindered interpretation of independent main effects.

Impact of kaolin-based particle film dusts on Callosobruchus maculatus (F.) and C. chinenesis (L.) after different storage periods of treated broad bean seeds

Adults of Callosobruchus maculatus (F.) and C. chinenesis (L.) were exposed to broad been seeds treated with kaolin-based particle film dusts (powder) at different concentrations 1.0, 0.8, 0.6, 0.4, 0.2, 0.1, 0.05, 0.025% w/w and untreated control. The effect of kaolin powder film was clearly effective in the first month of storage period of the treated seeds resulted a 100% protection of treated seeds at high concentrations from 1.0 to 0.2 w/w for both tested insects. After three months of storage of the treated seeds only the highest two concentrations 1.0 and 0.8 w/w gave a 100% protection for both tested insects. After six months of storage of the treated seeds, kaolin powder still could protect the broad bean seeds against C. maculatus and C. chinensis attacks although the efficacy of kaolin powder decreased with aging. Thus, residual effect of Kaolin powder film was reduced by prolongation of the storage period. A negative relationship was recorded between the kaolin concentration and the tested biological parameters (number of eggs laid, hatchability, developmental period, F 1 adult emergence, and seeds weight loss%) for both tested insects C. maculatus and C. chinensis . The comparison of the kaolin application methods, kaolin powder was more effective than kaolin suspension which gave a better protection to the treated seeds. Broad bean seeds viability was slightly affected by kaolin powder application, the reduction of germination was most greatest at highest concentration. Keywords : Kaolin powder, Broad been seeds, Protection, Callosobruchus maculatus (F.), C. chinenesis (F.).

Impact of kaolin particle film, spirodiclofen acaricide, harpin protein, and an organic biostimulant on pear psylla Cacopsylla pyri (Hemiptera: Psyllidae)

Pear psylla Cacopsylla pyri (L.) is among the most serious pests in pear orchards. Field studies were conducted in 2005 and 2006 on pear trees (Pyrus communis L.) to assess the effect of kaolin-based particle film, spirodiclofen acaricide, harpin protein, and an organic biostimulant on C. pyri infestations. Pear psylla nymph densities were effectively suppressed over the entire season by kaolin particle film and spirodiclofen treatments compared with the untreated control. Harpin protein protected pear trees almost as well as the spirodiclofen acaricide, while the organic biostimulant provided no protection. Kaolin particle film, spirodiclofen, and harpin protein-sprayed pear trees significantly outperformed their unsprayed counterparts in terms of fruit load. Based on the results of this study, it seems that kaolin particle film, spirodiclofen, and harpin protein could be used as alternatives to broad-spectrum insecticides for suppressing pear psylla infestations.

Particle Film Mechanisms of Action That Reduce the Effect of Environmental Stress in ‘Empire’ Apple

Heat stress is a limiting factor of plant productivity throughout the world and kaolin-based particle films (PF) have demonstrated that the reflective nature of the resulting plant surface can increase plant productivity primarily by reducing temperature in fruit, leaf, and canopy. The purpose of this study was to evaluate the environmental mechanisms and related physiological responses of ‘Empire’ apple (Malus ×domestica) gas exchange at the canopy level to PF treatments to identify those parameters key to plant response and increased plant productivity. Trees received either no treatment or season-long applications of a PF treatment and each treatment either received no supplemental irrigation or full replacement of evapotranspiration. Studies were begun in 1998 and continued to 2007. Fruit number and fruit weight were measured in all years. Whole canopy carbon dioxide assimilation rates (A) were measured in apple for a 4-year period to determine the relationship with incoming light and vapor pressure deficit (VPD) levels. The photosynthetic response to the irrigation and PF treatments varied between years as a result of environmental variation in VPD and photosynthetically active radiation (PAR) levels. There was a unique treatment response for PAR levels greater than 1600 μmol·m−2·s−1 in which the combination of PF and irrigation maintained midday A at maximum levels compared with other treatments although A was reduced by increasing VPD. This response indicated that although VPD limited A, the combination of PF and adequate water could maintain maximum A rates at full sun levels during the midday period and minimize the midday depression of A that is commonly observed and reduces the daily carbon accumulation. The increased carbon accumulation during the midday period was likely partitioned to the fruit. Increased fruit weight resulting from the PF treatment, compared with the control, was positively correlated with the growing season air temperature and VPD indicating that as the environment becomes hotter and/or drier, the magnitude of the PF response increased as a result of the reduced leaf and fruit temperature and the subsequent physiological effect. The PF treatments reduced radiation and heat load on exposed leaves enabling them to better regulate leaf temperature and improved the light distribution inside the canopy resulting in increased carbon gain at the whole plant scale. Fruit hue angle was reduced and red color improved by PF treatments in 5 of 10 years. The use of PF may be an effective substitute for evaporative cooling to reduce solar injury and to improve apple quality through increased fruit weight. The results indicate that benefits of PF treatments would occur in agroecosystems with large VPDs and high temperatures and that use of irrigation would further enhance the benefits at high PAR levels.

Kaolin-based particle film technology affects tomato physiology, yield and quality

Environmental stress can affect development and yield of tomato plants. This study was undertaken to investigate the underlying mechanism asserted by kaolin on tomato physiology by evaluating its effect on leaf, canopy and inner fruit temperatures, gas exchange at the leaf and canopy scales, above ground biomass, yield and fruit quality. The study was carried out under field conditions in Southern Italy. Treatments were plants treated with kaolin-based particle film (Surround ® WP) suspension and untreated plants (control). Kaolin application slightly increased leaf and canopy scale temperatures by 1.0 and 0.4 °C, respectively, transpiration rate decreased at both scales. On calm days (wind speed <0.5 m s −1) with a prevalently clear sky at midday, inner fruit temperature ( t f) of kaolin-treated plants was 4.4 °C lower than the t f of control plants, while in days with clear sky-windy, and cloudy-calm, the t f did not differ. At leaf scale, net assimilation was reduced by 26% in kaolin-coated treatments. Stomatal conductance decreased by 53%, resulting in reductions of 34 and 15% in transpiration and internal CO 2 concentration, respectively. Gas exchange parameters measured at canopy scale were similarly affected. In kaolin-treated plants, assimilation and evapotranspiration rates were reduced by 17 and 20%, respectively, while dark respiration was not affected. Above ground dry biomass decreased by 6.4%. Marketable yield in kaolin-treated plants was 21% higher than those measured in control plants; this is possibly related to the 96 and 79% reduction in sunburned fruit and those damaged by insects, respectively, and to the 9% increase in mean fruit weight. Kaolin treatment increased lycopene fruit content by 16%, but did not affect total soluble solids content, fruit dry matter, juice pH, titratable acidity or tomato fruit firmness. The use of kaolin-based particle film technology would be an effective tool to alleviate heat stress and to reduce water stress in tomato production under arid and semi-arid conditions.