| For 2020 and newer grants, please go to https://grants.ipmcenters.org/ |
|---|
|
|
| Home Current RFAs PD User Guide Projects Login |
|
Funded Project |
|
Funding Program:
Regional IPM Competitive Grants - Northeastern |
|
Project Title:
Scale Management in Christmas Trees |
Project Directors (PDs):
|
|
Lead State: CT Lead Organization: Connecticut Agricultural Experiment Station |
| Extension Funding: $45,473 |
| Research Funding: $45,027 |
|
Start Date: Sep-01-2011 End Date: Aug-31-2013 |
|
Site/Commodity: Christmas trees |
|
Summary:
Foliar sprays to suppress cryptomeria and elongate hemlock scales prevent implementation of IPM in Christmas tree plantations in the northeast because they are toxic to natural enemies. Three tools will transform growers' practices: (1) chemical control: a reduced-risk insecticide applied to the trunk of the tree is directly absorbed and translocated to foliage, where it selectively kills scales, (2) biological control: several fungi found to infect armored scales will be cultured and then applied to trees, with or without whey adjuvants, to cause infections, and (3) cultural control: decreasing nitrogen fertility should reduce the intrinsic rate of growth for scales so that the existing complex of natural enemies can maintain scale populations below damaging levels. In published research trials the basal trunk spray of dinotefuran suppressed scale populations while conserving natural enemies; extension specialists in NJ, PA and RI will demonstrate this technique to growers with infested plantations. Several fungi found to infect the two targeted armored scales may provide a higher degree of selectivity than commercialized insect pathogenic fungi; if effective, these fungi could be registered through the IR-4 program. Adjustments in soil nitrogen fertility are expected to create growing conditions optimal for Christmas trees and less favorable to scales. The options being developed should readily be adopted by growers because they will be less expensive, more effective, and less toxic to the applicator and to the environment than current practices. A scale management web guide will extend the findings to growers.
Objectives: (1) Demonstrate compatibility of an optimized systemic insecticide application method with naturally occurring predators and parasites (Extension Objective) (2) Test commercially available and field-collected insect pathogenic fungi against armored scales (Research Objective) (3) Measure the influence of nitrogen fertilization on scale population, scale natural enemy population, and Christmas tree growth (Research Objective) (4) Publish a web-based guide to the biology and management of armored scales (Extension Objective) Proposal |
|
Interim Report: Jan-02-2013 |
|
Impacts Research Component: Objective 1. Test commercially available and field-collected insect pathogenic fungi against armored scales. Sadly, our colleague and expert on adjuvants for improving performance of insect pathogenic fungi, Dr. Scott Costa, of the University of Vermont, passed away on June 6, 2012. His portion of the investigations is now being conducted at the CAES by Drs. Li and Cowles. Insect pathogenic fungi originating from field collections from elongate hemlock scale (Metarhiziopsis microspora, Colletotrichum acutatum var. fioriniae, and Cladosporium spp.) were grown in the laboratory on various grain substrates, and spore and/or hyphal fragment preparations sprayed onto cover slips in the lab and scale populations in the field to determine their efficacy against armored scales, as measured by percent infection rates and the scales' population growth. Objective 2. Measure the influence of nitrogen fertilization on scale population, scale natural enemy population, and Christmas tree growth. Fertilizer was applied to individual trees in a 10-replicate experiment manipulating the nitrogen fertility for Fraser fir Christmas trees grown at the Pinchbeck Farm in Guilford, CT, which had not been fertilized since 1992; both cryptomeria scale and E. citrina are present, and the scales are currently maintained at low population density via biological control. Dosages were 0, 40, 100, and 250 lb N applied as 10-10-10 fertilizer. Measurements of terminal growth and color ratings for trees were made in November, 2012, to determine whether and to what degree the nitrogen fertilization affected the growth rate of Christmas trees. Extension Component: Objective 1. Demonstrate compatibility of an optimized systemic insecticide application method with naturally occurring predators and parasites. Cooperating growers were chosen for randomized design demonstration trials in PA, NJ, and RI. Farms were chosen for their abundance of armored scales and willingness of the grower to participate in this two-year demonstration. Dr. Steven Alm, University of Rhode Island, The York County Extension Advisor (PA), Mr. Timothy Abbey, and Rutgers University extension forestry specialist Dr. Mark Vodak applied Safari 20 SG approximately 2 3 weeks prior to bud break, using a Solo backpack sprayer equipped with a 21 p.s.i. control flow valve pressure regulator and 6502E flat fan nozzle oriented vertically to direct a calibrated basal bark spray. The sprayers were calibrated to deliver 0.75 - 1 lb of Safari 20SG per acre, with the per acre dosage determined by the average height of trees in the treatment area. The dosage for each tree was adjusted based upon its size, with small trees receiving approximately 15 ml total, and trees over 6 feet in height receiving up to 60 ml. The treated trees were compared with adjacent untreated control trees within the planting, and/or with other plantings of trees that the grower managed according to standard procedures. Samples representative of these groups of trees were collected from PA and RI participants, and were assessed with microscopic examination by R. Cowles to determine live scales and percent parasitism and predation of scales. Objective 4. Publish a high-quality guide to the biology and management of armored scales. Photographs and text are being assembled to generate a high-quality color web publication on the biology and management of armored scales in Christmas trees. |
|
Outcomes Research Component: Objective 1. Test commercially available and field-collected insect pathogenic fungi against armored scales. Sadly, our colleague and expert on adjuvants for improving performance of insect pathogenic fungi, Dr. Scott Costa, of the University of Vermont, passed away on June 6, 2012. His portion of the investigations is now being conducted at the CAES by Drs. Li and Cowles. Insect pathogenic fungi originating from field collections from elongate hemlock scale (Metarhiziopsis microspora, Colletotrichum acutatum var. fioriniae, and Cladosporium spp.) were grown in the laboratory on various grain substrates, and spore and/or hyphal fragment preparations sprayed onto cover slips in the lab and scale populations in the field to determine their efficacy against armored scales, as measured by percent infection rates and the scales' population growth. Objective 2. Measure the influence of nitrogen fertilization on scale population, scale natural enemy population, and Christmas tree growth. Fertilizer was applied to individual trees in a 10-replicate experiment manipulating the nitrogen fertility for Fraser fir Christmas trees grown at the Pinchbeck Farm in Guilford, CT, which had not been fertilized since 1992; both cryptomeria scale and E. citrina are present, and the scales are currently maintained at low population density via biological control. Dosages were 0, 40, 100, and 250 lb N applied as 10-10-10 fertilizer. Measurements of terminal growth and color ratings for trees were made in November, 2012, to determine whether and to what degree the nitrogen fertilization affected the growth rate of Christmas trees. Extension Component: Objective 1. Scale populations assessed from the PA trial showed no statistical differences (P = 0.11) between the untreated and treated trees, with averages of 0.75, 2.8, and 2.1 scales per needle in trees receiving the basal bark spray of Safari, conventional sprays, and the untreated check, respectively. The numbers of parasitoid exit holes from scale tests in a 100 needle sample significantly differed among treatments, with means of 1.8, 3.2, and 8.2, (treatments in the same order as before), but the percent parasitism did not differ and were 4, 1, and 3%, respectively. Cooperators in Rhode Island provided comparisons between a basal bark spray with Safari and conventional practices on two farms, vs. untreated trees at a third farm. Growers in RI have recognized dinotefuran (Safari) as being a superior insecticide for scale management, and so the conventional treatments were separate foliar applications of dinotefuran and chlorpyrifos. Scale counts were extremely low from these farms. On Farm 1, scale counts were 0.003 per needle in the conventional treatment, 0.000 from the basal bark spray. On Farm 2, the averages were 0.03 and 0.000 per needle. For Farm 3, where the untreated check averaged 0.69 scales per needle and the Safari basal bark spray 0.000, with highly significant differences between treatments (P < 0.0001). Trees in Rhode Island were between 4 and 6 feet in height, a size of tree in which the bark spray method works particularly well. Growers in Rhode Island and New Jersey recognize that the basal bark spray method is highly effective, and have adopted this as a standard treatment to manage scales in their plantations. This has led to some difficulty in being able to compare the dinotefuran basal spray treatment with practices that this method has replaced. |
|
Impacts Modifications of growers practices involving soil fertility or management with insect pathogenic fungi did not occur, as these methods could not be implemented. The basal bark spray with dinotefuran for management of armored scales has been widely adopted among the states participating in the outreach portion of this project (CT, NJ, PA, and RI), along with one adjoining state (MA). One grower in CT has modified a Ventrac mower with a basal bark sprayer that is activated to spray the trunks with an electric eye. This sprayer has performed so well on this farm that the sprayer may be commercialized. The outreach/extension portion of this project culminated in posting of three educational videos, available at http://www.ct.gov/caes/cwp/view.asp?a=2826&q=438910&caesNav=| Also on YouTube at: https://www.youtube.com/user/CTAGEXPSTATION |
|
Outcomes Experiments on the experimental methods to suppress armored scales in Christmas trees were uniformly negative in outcomes. Although the various species of fungi were readily cultured on various grains, and millet was the most productive, laboratory tests of these three fungi with and without the Mycomax adjuvant did not enhance spore germination or sporulation. Furthermore, field application of these fungi with or without Mycomax did not lead to evidence of infections in scales. Application of fertilizer did not lead to any evidence of greater scale survival or reproduction (P = 0.71), with average scale populations of 0.72, 0.56, 0.76, and 0.68 live scales per needle with the field nitrogen application dosages increasing to 0, 40, 100, and 250 lb N, respectively. Percent parasitism was very low throughout the plots and did not vary among fertility treatments (P = 0.35), ranging from 1.3 to 3.7% of total scales. Percent predation, as evident from partial remains of scale covers or evidence of missing scales, also did not differ among fertilizer treatments (P = 0.10), and varied from 7.7 to 13% of total scales. There were no measured differences among fertility levels related to growth of the main leader, side shoots, or overall color (P = 0.47, 0.10 and 0.32, respectively). The lack of differences reflect the difficulty in manipulating foliar nitrogen in these trees. Analyses of foliar nitrogen levels in these groups of trees was nearly invariable, with means from different fertilizer application groups ranging from 1.46 to 1.52 percent nitrogen. The ordering of mean nitrogen levels was random, and there were no differences among treatment groups. |
|
Final Report: |
|
Impacts Modifications of growers practices involving soil fertility or management with insect pathogenic fungi did not occur, as these methods could not be implemented. The basal bark spray with dinotefuran for management of armored scales has been widely adopted among the states participating in the outreach portion of this project (CT, NJ, PA, and RI), along with one adjoining state (MA). One grower in CT has modified a Ventrac mower with a basal bark sprayer that is activated to spray the trunks with an electric eye. This sprayer has performed so well on this farm that the sprayer may be commercialized. The outreach/extension portion of this project culminated in posting of three educational videos, available at http://www.ct.gov/caes/cwp/view.asp?a=2826&q=438910&caesNav=| Also on YouTube at: https://www.youtube.com/user/CTAGEXPSTATION |
|
Outcomes Experiments on the experimental methods to suppress armored scales in Christmas trees were uniformly negative in outcomes. Although the various species of fungi were readily cultured on various grains, and millet was the most productive, laboratory tests of these three fungi with and without the Mycomax adjuvant did not enhance spore germination or sporulation. Furthermore, field application of these fungi with or without Mycomax did not lead to evidence of infections in scales. Application of fertilizer did not lead to any evidence of greater scale survival or reproduction (P = 0.71), with average scale populations of 0.72, 0.56, 0.76, and 0.68 live scales per needle with the field nitrogen application dosages increasing to 0, 40, 100, and 250 lb N, respectively. Percent parasitism was very low throughout the plots and did not vary among fertility treatments (P = 0.35), ranging from 1.3 to 3.7% of total scales. Percent predation, as evident from partial remains of scale covers or evidence of missing scales, also did not differ among fertilizer treatments (P = 0.10), and varied from 7.7 to 13% of total scales. There were no measured differences among fertility levels related to growth of the main leader, side shoots, or overall color (P = 0.47, 0.10 and 0.32, respectively). The lack of differences reflect the difficulty in manipulating foliar nitrogen in these trees. Analyses of foliar nitrogen levels in these groups of trees was nearly invariable, with means from different fertilizer application groups ranging from 1.46 to 1.52 percent nitrogen. The ordering of mean nitrogen levels was random, and there were no differences among treatment groups. |
| Close Window |
|
Northeastern IPM Center 340 Tower Road Cornell University Ithaca, NY 14853 NortheastIPM.org |
 |
Developed by the Center for IPM © Copyright CIPM 2004-2026 |
|