Source: UNIVERSITY OF ARIZONA submitted to NRP
POTENTIAL USE OF PARTICLE FILM TECHNOLOGY FOR A BIORATIONAL APPROACH FOR MANAGEMENT OF CITRUS THRIPS ON ARIZONA LEMONS
Sponsoring Institution
National Institute of Food and Agriculture
Project Status
COMPLETE
Funding Source
HATCH
Reporting Frequency
Annual
Accession No.
0186937
Grant No.
(N/A)
Cumulative Award Amt.
(N/A)
Proposal No.
(N/A)
Multistate No.
(N/A)
Project Start Date
Oct 1, 2000
Project End Date
Sep 30, 2005
Grant Year
(N/A)
Program Code
[(N/A)]- (N/A)
Recipient Organization
UNIVERSITY OF ARIZONA
888 N EUCLID AVE
TUCSON,AZ 85719-4824
Performing Department
ENTOMOLOGY
Non Technical Summary
Particle film technology offers a biorational approach to managing citrus thrips in citrus. This project examines the potential of integrating particle film into a citrus IPM program, and reducing the reliance on harsh insecticides.
Animal Health Component
80%
Research Effort Categories
Basic
(N/A)
Applied
80%
Developmental
20%
Classification

Knowledge Area (KA)Subject of Investigation (SOI)Field of Science (FOS)Percent
2110930113050%
2160930113050%
Knowledge Area
211 - Insects, Mites, and Other Arthropods Affecting Plants; 216 - Integrated Pest Management Systems;

Subject Of Investigation
0930 - Lemon;

Field Of Science
1130 - Entomology and acarology;
Goals / Objectives
Objective 1) To determine the most efficacious application timings of kaolin for citrus thrips control. Lemons are susceptible to scarring by thrips from petal fall until the fruit reaches ca. 2.5 cm in diameter. Early research has demonstrated that it is essential to maintain coverage of kaolin on flush lemon foliage and fruit during this period to avoid fruit scarring. Previous experiments also indicate that applications of kaolin do not result in a rapid decline of established thrips populations. This indicates that kaolin should be applied prior to the buildup of thrips concurrently with the setting of fruit, it is not certain with kaolin if there are benefits to applying it prior to fruit set when thrips populations are low. In this portion of the study we will make comparisons of the timing of applications to determine if kaolin is more effective when applied pre-bloom, at bloom, or post petal fall. Objective 2) To determine the minimum spray gallonage necessary for adequate thrips control. Most ground insecticide applications made in Arizona citrus are applied at volumes of 475-950 l/ha. Although these spray volumes may be sufficient for citrus thrips control with convention insecticides, they probably would not provide adequate coverage of a physical barrier such as kaolin. Currently, the manufacturer suggests that kaolin be applied at volumes 2,400 l/ha or more. By decreasing the speed of their sprayers, Arizona growers are capable of applying 2,400 l/ha. However, they are reluctant to do so because it would greatly increase the time required to make an application. Currently, there is very little information available concerning how low of a spray volume we can use and still get adequate coverage with kaolin. In this portion of the study we will compare the efficacy of kaolin treatments applied at various spray volumes. Objective 3) To evaluate the compatibility of kaolin with other thripsicides when tank mixed. There is very little information concerning the compatibility of kaolin with insecticides. Kaolin does not rapidly reduce existing thrips populations. It is conceivable that some growers will want to use kaolin, but will need the assistance of other insecticides to reduce existing thrips populations. In this study we will evaluate efficacy kaolin / insecticide tank mixes. Objective 4) Investigate the impact of kaolin on other citrus pests and insect natural enemies. In this portion of the study, we will apply kaolin and observe its impact on predacious insects and mites, and given the opportunity, we will evaluate its impact on other citrus pests.
Project Methods
Objective 1. To determine the most efficacious application timings of kaolin for citrus thrips control. Treatments will include an untreated check, and applications of kaolin applied beginning prebloom during the flower bud stage, during bloom, and immediately following petal fall, period when ca. 70 percent of the blooms have fallen. Treatments will continue as needed to maintain coverage until the fruit reaches 2.5 cm in diameter. Prior to fruit set, thrips will be sampled utilizing beat pan. After fruit set, thrips will also be sampled weekly by counting the number of infested fruit. Ten fruit will be sampled per tree. Near harvest, fruit damage will be estimated by rating the degree of scarring to the rind. Differences among insecticide treatments for beat pan samples, fruit infestation, and fruit damage will be statistically analyzed using ANOVA and an F protected LSD, P=0.05. Objective 2. To determine the minimum spray gallonage necessary for adequate thrips control. Treatments will include an untreated check, and applications of Kaolin applied at 480, 960, 1,140 and 2,400 l per ha. Treatments will begin at petal fall and will continue as needed to maintain coverage until the fruit reaches 2.5 cm in diameter. Thrips will be sampled weekly by counting the number of infested fruit. One hundred fruit will be sampled per plot. Near harvest, fruit damage will be estimated by rating the degree of scarring to the rind. Fruit damage assessment and statistical analysis of data will be conducted as described in objective 1. Objective 3. To evaluate the compatibility of kaolin with other thripsicides when tank mixed. Treatments will include an untreated check, kaolin, several commercial standard insecticides alone and in combination with kaolin. Thrips will be sampled weekly by counting the number of infested fruit. Ten fruit will be sampled per tree. Near harvest, fruit damage will be estimated by rating the degree of scarring to the rind. Near harvest, fruit damage will be estimated by rating the degree of scarring to the rind. Fruit damage assessment and statistical analysis of data will be conducted as described in objective 1. Objective 4. Investigate the impact of kaolin on other citrus pests and insect natural enemies. Treatments will consist of untreated check, a kaolin regime, a standard broad spectrum insecticide regime, and a non-kaolin biorational insecticide regime. All treatments will continue until the fruit reaches 2.5 cm in diameter. Thrips and phytophagous will be sampled weekly by counting the number of infested fruit. One hundred fruit will be sampled per plot. Phytophagous mites and predacious insects will also be sampled using beat pan samples of foliage. Twenty samples will be taken weekly per plot. Other insect pests and predators will be evaluated using appropriate techniques as they occur. Near harvest, fruit damage will be estimated by rating the degree of scarring to the rind. Fruit damage assessment and statistical analysis of data will be conducted as described in objective 1.

Progress 10/01/00 to 09/30/05

Outputs
The kaolin based products, Surround WP and Snow, were evaluated for their ability to manage citrus thrips populations in lemons on the Yuma Mesa, and their impact on lemon yield, fruit quality, and packout. Both Surround and Snow effectively controlled citrus thrips and prevented fruit scarring. Surround produced higher yields than either Snow or the commercial standard at the first harvest (#9 ring). There were no differences in yield among treatments for the second (strip) harvest, nor were there any differences in total yield. These data suggest that Surround may increase fruit earliness or sizing. There were no statistical differences among any of the treatments in fruit size frequency or quality for any of the harvests, and there was no apparent benefit from applying an additional application of Surround or Snow post thrips season solely for quality, fruit size, or yield enhancement. The activity of Surround does not appear to be adversely affected by the inclusion of the insecticides Danitol, Baythroid, Carzol, or Success, nor do these insecticides appear to be adversely affected by Surround. Foliar fertilizers did not appear to adversely affect the activity of Surround when tank mixed. However, there is some evidence that Surround may negatively affect the absorption of Fe and Mn when tank mixed with Zn, Fe, Mn lignosulfonate, but this data is not conclusive. The addition of a non-ionic surfactant appears to enhance the on-leaf distribution of Surround over light petroleum and paraffin based oils, but long term efficacy is not affected. Various application volumes 250, 200, 150, 100 gallons/ac were evaluated. Only the 50 gallons/ac volume failed to offer adequate control. Rates of Surround evaluated in various trials ranged from 150 lbs/ac to 35 lbs/ac. No differences were detected among rates. During the 2005 year of the study, Surround and Snow were evaluated in commercial lemon groves as demonstrations. Both products effectively prevented citrus thrips damaged to mature and non-bearing trees. Protection was equivalent to commercial standard, but required one to two additional applications depending on the site. Growers commented that the product worked well and that they liked the sun protection and increased growth in addition to the protection from thrips. However, the growers thought the cost of using the technology was currently too high. Lastly, there is concern that in groves infested with whiteflies or mealybug that the kaolin product increased the problem by repelling the parasitoids.

Impacts
Kaolin appears to be a viable replacement for OP and carbamate insecticides for control of citrus thrips. However, there are several problems with kaolin that will and is hampering its acceptance: 1) It is does not have a good fit in situations where mealybugs, scales, or whiteflies occur since it adversely affects parasitoids, 2) It is substantially more costly than traditional citrus thrips control methods, 3) Some local pesticide supply companies are reluctant to stock kaolin since it is used in very large volumes and requires a great deal of warehouse floor space. Where is has been used, the growers have been very satisfied with its performance.

Publications

  • No publications reported this period


Progress 01/01/04 to 12/31/04

Outputs
The kaolin based products Surround WP and Snow were evaluated over a three year period for their ability to manage citrus thrips populations in lemons on the Yuma Mesa, and their impact on lemon yield, fruit quality, and packout. In large, 2 ac plot trials Surround at 50 lbs/ac and Snow at 80 lbs/ac effectively controlled citrus thrips and prevented fruit scarring. Small plot trials suggest that Surround rates may be reduced to as little as 35 lbs/ac and still achieve acceptable control of citrus thrips. Although Surround and Snow were both efficacious against citus thrips, there is some evidence that suggests incompatibility of these products with IPM programs where parasitoids are important. In our trials we experienced one year were these products appeared to flare mealybugs due to parasitod exclusion. Preference tests indicated that both Surround and Snow act primarily by repelling the thrips, but also induce some mortality. Surround appears to have some horticultural benefits. Surround consistently produced higher yields than either Snow or the commercial standard at the first harvest (#8 or 9 ring). There were no differences in yield among treatments for the second (strip) harvest, nor were their any differences in total yield. These data suggest that Surround may increase fruit earliness or sizing. There were no statistical differences among any of the treatments in fruit size frequency or quality for any of the harvests, and there was no apparent benefit from applying an additional application of Surround or Snow post thrips season solely for quality, fruit size, or yield enhancement. The activity of Surround does not appear to be adversely affected by the inclusion of the insecticides Danitol, Baythroid, Carzol, or Success, nor do these insecticides appear to be adversely affected by Surround. Foliar fertilizers did not appear to adversely affect the activity of Surround when tank mixed. However, there is some evidence that Surround may negatively affect the absorption of Fe and Mn when tank mixed with Zn, Fe, Mn lignosulfonate, but this data is not conclusive. The addition of a non-ionic surfactant appears to enhance the on-leaf distribution of Surround over light petroleum and paraffin based oils, but long term efficacy is not affected.

Impacts
Kaolin appears to be a viable replacement for OP and carbamate insecticides for control of citrus thrips. However, there are several problems with kaolin that will and is hampering its acceptance: 1) It is does not have a good fit in situations where mealybugs, scales, or whiteflies occur since it adversely affects parasitoids, 2) It is substantially more costly than traditional citrus thrips control methods, 3) Some local pesticide supply companies are reluctant to stock kaolin since it is used in very large volumes and requires a great deal of warehouse floor space. Where is has been used, the growers have been very satisfied with its performance.

Publications

  • Kerns, D. L. and G. C. Wright. 2001. Insecticidal and Yield Enhancement Qualities of Surround Particle Film Technology in Citrus. In College of Agriculture, 2001 Citrus and Deciduous Fruit and Nut Research Report, Series P-129, pp. 11-16.
  • Kerns, D. L. and G. C. Wright. 2003. Particle Film Technologies: Pest Management and Yield Enhancement Qualities in Lemons. In College of Agriculture, 2003 Citrus and Deciduous Fruit and Nut Research Report, pp. 25.
  • Kerns, D. L. and D. L. Kerns. 1998. Commercial evaluation of M 96 015 for control of citrus mealybug, woolly whitefly and citrus thrips in lemons. In College of Agriculture, 1998 Citrus and Deciduous Fruit and Nut Research Report, Series P 113, pp. 16 20.
  • Kerns, D. L. and T. Tellez. 1999. Efficacy of insecticides to citrus thrips on lemons in Yuma Arizona 1998. In College of Agriculture, 1999 Citrus and Deciduous Fruit and Nut Research Report, Series P-117, pp. 1-11.
  • Kerns, D. L. and G. C. Wright. 2000. Protective and yield enhancement qualities of kaolin on lemons. In College of Agriculture, 2000 Citrus and Deciduous Fruit and Nut Research Report, Series P-123, pp. 14-20.


Progress 01/01/02 to 12/31/02

Outputs
A number of experiments have been conducted adressing the objectives: 1) To determine the most efficacious application timings of kaolin for citrus thrips control. 2) To determine the minimum spray gallonage necessary for adequate thrips control. 3) To evaluate the compatibility of kaolin with other thripsicides when tank mixed. 4) Investigate the impact of kaolin on other citrus pests and insect natural enemies. Results: 1) Thus far it appears that kaolin is most efficacious when applied at or just prior to petal fall. Later applications can be effective but may require the addition of a faster acting insecticide to reduce economically damaging level of citrus thrips if present. 2) Kaolin appears to provide adequate coverage and subsequent control at spray volumes of 250, 150, 100 and 50 gal/ac. Essentially, it appears that any spray volume utilized will suffice as long as the overage looks good visually. The amount of spray volume required will depend greatly on the efficiency of the sprayer. 3) Kaolin appears to be compatible with many insecticides including dimethoate, formetamate HCL, abamectin, spinosad and cyfluthrin. However, there may be some compatibility problems with oxamyl. 4) Kaolin appears to have little if any impact on phytophagous or predaceous mites, but it does appear to repel mealybug parasitoids. Thus it's fit into citrus IPM programs is questionable where the role of parasitoids is important.

Impacts
Kaolin appears to be a viable replacement for OP and carbamate insecticides for control of citrus thrips. However, there are several problems with kaolin that will and is hampering its acceptance: 1) It is does not have a good fit in situations where mealybugs, scales, or whiteflies occur since it adversely affects parasitoids, 2) It is substantially more costly than traditional citrus thrips control methods. I am currently investigating more cost competitive use rates, 3) Some local pesticide supply companies are reluctant to stock kaolin since it is used in very large volumes and requires a great deal of warehouse floor space. Where is has been used, the growers have been very satisfied with its performance.

Publications

  • Kerns, D. L. and Glenn Wright. 2002. Pest Management and yield Enhancement Qualities of Particle Film Technologies in Citrus. In College of Agriculture, 2002 Citrus and Deciduous Fruit and Nut Research Report, Series P-133, pp. 52-61.
  • Zerkoune, M., C. Wright, D. Kerns and W. McCloskey. 2001. Organic Lemon Production. In College of Agriculture, 2001 Citrus and Deciduous Fruit and Nut Research Report, Series P-129, pp. 37-44.


Progress 01/01/01 to 12/31/01

Outputs
Significant progress has been made on this on-going program. We have found the several particle film formulations can effective manage citrus thrisp, Scirtothrips citri, in lemons under extremely high insect pressure. Additional aspects we have been investigating include mode of action, effects of spray volume, effects of additives such as adjuvants, foliar fertilizer, and insecticides, and impacts of yield, fruit size and earliness. We have tentatively found that kaolin acts by repelling both adult and nymph citrus thrips, but also causes ca. 25% mortality. Effective spray coverage can be obtained with as little as 50 gallons per acre, but benefits greatly from some spray adjuvants. We have observed no problems tank mixing with insecticides, but some foliar fertilizer may have adverse affects. Lastly, our data suggests that lemons treated with kaolin yield more fruit eariler.

Impacts
Wide spread aboption of kaolin use in Arizona citrus could eliminate the need for traditional insecticides in most years. Benefits could be far reaching in the incidence of seconadry pest out breaks and worker safety.

Publications

  • Kerns, D. L. and G. C. Wright. 2001. Insecticidal and Yield Enhancement Qualities of Surround Particle Film Technology in Citrus. In College of Agriculture, 2001 Citrus and Deciduous Fruit and Nut Research Report, Series P-129, pp. 11-16.
  • Zerkoune, M., C. Wright, D. Kerns and W. McCloskey. 2001. Organic Lemon Production. In College of Agriculture, 2001 Citrus and Deciduous Fruit and Nut Research Report, Series P-129, pp. 37-44.
  • Kerns, D. L. and T. Tellez. 2001. Evaluation of Pre-Petal Fall Citrus Thrips Control. In College of Agriculture, 2001 Citrus and Deciduous Fruit and Nut Research Report, Series P-129, pp. 5-10.
  • Kerns, D. L. and G. C. Wright. 2000. Protective and yield enhancement qualities of kaolin on lemons. In College of Agriculture, 2000 Citrus and Deciduous Fruit and Nut Research Report, Series P-123, pp. 14-20.


Progress 01/01/00 to 12/31/00

Outputs
This project did not begin until 10/01/2000, and although trials are currently being conducted, there is insufficent data to report any results.

Impacts
None as of yet.

Publications

  • No publications reported this period