2009 FINAL REPORT, Cone and Seed Pest Group, B.C. Ministry of Forests

Transcription

1 2009 FINAL REPORT, Cone and Seed Pest Group, B.C. Ministry of Forests TITLE Cone and Seed Pest Pesticide Trials at Kalamalka Forestry Centre Ministry Contract No. RE1051Y051 SPRUCE DATE September 22, 2009 RESEARCHERS Lead researcher: Mario Lanthier Technicians: Sonja Peters, B.Sc., Jeanette Merrick certified arborist ISA CropHealth Advising & Research P.O. Box 28098, Kelowna, British Columbia, V1W 4A6 Phone: (250) , COOPERATOR Dr. Ward Strong, B.C. Ministry of Forests and Range, OBJECTIVES Field test the efficacy and phytotoxicity of various insecticides for control of target insect pests on outdoor-grown conifer trees in seed cone orchards. TECHNICAL BACKGROUND Conifer seed orchards in British Columbia face a number of serious insect pest problems 1. One pesticide currently registered for these insects is Cygon 480, a commercial formulation of dimethoate 2. Dimethoate is an organophosphorous chemical coumpound 3. In recent years, the labelled uses have been severely reduced for other organophosphorous insecticides such as diazinon 4, chlorpyrifos 5 and azynphos-methyl 6. It is expected the labelled uses of dimethoate may also be severely modified following an upcoming review by the Pest Management Regulatory Agency (PMRA), a federal agency 7. The Forest Genetics Council of British Columbia Committee is examining newer pesticides currently registered on other crops in Canada as possible management tools for seed orchards. This Council is appointed by British Columbia s chief forester and funded by the Forest Investment Account of BC 8. The current project is a screening of various products to document effectiveness on target pest and phytotoxicity on host plants. The products were selected based on their specificity, mode of action, and worker and environmental safety. 1 See a complete list at the BC government website 2 Seed Orchard and Cone & Seed Pest Management. Chapter 14 in Nursery & Landscape Pest Management & Production Guide. Published 2008 by British Columbia Landscape & Nursery Association. Surrey, B.C. 3 R.W. Adams editor Handbook for Pesticide Applicators and Dispensers. Fifth Edition. B.C. Ministry of Environment. Victoria, B.C. Page Pest Management Regulatory Agency Proposed Re-evaluation Decision: Diazinon. PRVD Pest Management Regulatory Agency Update on the Re-evaluation of Chlorpyrifos. REV Pest Management Regulatory Agency Update on Re-evaluation of Azinphos-methyl. REV Pest Management Regulatory Agency Status of Active Ingredients Under Re-Evaluation See 8 See the website 1

2 MATERIALS AND METHODS Crop Interior Spruce (Picea engelmanni X glauca) Target pests Main target: Fir coneworm (Dioryctria abietivorella, Lepidoptera: Pyrallidae) Secondary targets: Adelges cooleyi, Cydia strobilella, Kaltenbachiola rachiphaga, Megastigmus spp., Strobilomyia neanthracina The trial was conducted at the Kalamalka Research Station, located 3 km south of Vernon on Highway 97. The trial took place in Block 15. Plants selected were field-grown Spruces of different clone origin. TREATMENTS Treatment # Commercial product Current label rate 1 Untreated control 2 Grower control Dimethoate 480EC 2.5 L / 1000 L water / ha 3 Potential solution Intrepid 240F (1 application) 1.0 L / 1000 L water / ha 4 Potential solution Intrepid 240F (2 applications) 1.0 L / 1000 L water / ha 5 Potential solution Delegate WG (1 application) 420 gr / ha 6 Potential solution Delegate WG (2 applications) 420 gr / ha 7 Potential solution Movento 240SC (1 application) 485 ml / 500 L water / ha 8 Potential solution Movento 240SC (2 applications) 485 ml / 500 L water / ha 9 Potential solution Admire 240F (1 application) 380 ml / ha 10 Potential solution Admire 240F (2 applications) 380 ml / ha About the products tested Admire 240F, PCP registration # Active ingredient is imidicloprid 240g/L (group 4). Acute toxicity is moderate. Current registration is for a number of food crops, insects such as aphids, leafhoppers, leafminers and leaf beetles. Water solubility is 0.61 g/l. Delegate WG, PCP registration # Active ingredient is spinetoram 25% (group 5). Acute oral toxicity is low. Current registration is for apple fruit production (codling moth, plum curculio). Water solubility is 11.3 mg/l. A broad spectrum contact and stomach product, activity is from excitation of the insect nervous system with a low impact on beneficial insects. Dimethoate 480, PCP registration # Active ingredient is dimethoate 480g/L (group 1). Acute oral toxicity is moderate (LD 50 for rat is 215). Current registration includes Douglas fir seed cone insects. Water solubility is 25 g/l (or mg/l). The product has both contact and systemic activity. Intrepid 240F, PCP registration # Active ingredient is methoxyfenozide at 240 g/l (group 18). Acute oral toxicity is low. Current registration is for apple tree fruit (codling moth and leafrollers). This is an insect growth regulator (mimic of moulting hormone), effective on butterfly and moth larvae only. Movento 240SC, PCP registration # Active ingredient is spirotetramat 240 g/l (group 23). Acute oral toxicity is low. Current registration is for aphids, whiteflies and scale on fruit trees and grapes. Activity is from inhibition of lipid biosynthesis. The systemic activity is enhanced by addition of a spreading agent during application. Water solubility is 29.9 mg/l. 2

3 Experimental set-up A pre-trial screening of trees was done in early May. Of 94 trees selected, 90 were marked in the field to correspond to the site inventory number. The trial was set-up as a completely randomized design of 10 treatments X 9 replicates per treatment (one tree is one replicate) = 90 trees total. Table 1 Protocol treatments, mixing rate and application dates # Treatment Label rate Mixing in 10 L Date applied 1 Untreated control 2 Dimethoate 480EC 2.5 L / 1000 L 25.0 ml May 15 3 Intrepid 240F (1 spray) 1.0 L / 1000 L 10 ml May 15 4 Intrepid 240F (2 sprays) 1.0 L / 1000 L 10 ml May 15, May 29 5 Delegate WG (1 spray) 420 gr / ha 4.2 gr May 15 6 Delegate WG (2 sprays) 420 gr / ha 4.2 gr May 15, May 29 7 Movento 240SC (1 spray) 285 ml / 450 L 5.8 ml May 15 + Agral 90 (surfactant) ml 8 Movento 240SC (2 sprays) 285 ml / 450 L 5.8 ml May 15, May 29 + Agral 90 (surfactant) ml 9 Admire 240F (1 spray) 380 ml / ha 3.8 ml May Admire 240F (2 sprays) 380 ml / ha 3.8 ml May 15, May 29 Application Spray application was made following regular monitoring on-site and capture of the key pest (Dioryctria) in pheromone-baited traps in the trial block. Treatments were applied with hand-held back sprayers (Solo 475, Solo Inc., Newport News, VA) equipped with hollow cone nozzles (1.8 mm orifice). Five different sprayers were used, one for each different pesticide. Water was obtained on-site (ph 6.8 and Electrical Conductivity 0.18). The sprayer was filled with 1.2 to 1.5 liters of the spray mixture, depending on estimated tree size. Application was done at uniform pressure to obtain thorough coverage of all plant parts, especially the upper canopy in the cone-bearing portion, with some drip but no runoff. Amount of product remaining was measured after spraying each tree. Table 2 Mean (standard deviation) amount of spray solution applied per tree for each treatment # Treatment Mean solution applied (standard deviation) May 15 May 29 2 Dimethoate 480EC 1211 ml (232 ml) Intrepid 240F (1 st spray) 1233 ml (320 ml) Intrepid 240F (2 nd spray) 1167 ml (158 ml) 1189 ml (145 ml) 5 Delegate WG (1 st spray) 1050 ml (180 ml) Delegate WG (2 nd spray) 1122 ml (128 ml) 1156 ml (88 ml) 7 Movento 240SC (1 st spray) 1139 ml (267 ml) Movento 240SC (2 nd spray) 1061 ml (183 ml) 1156 ml (88 ml) 9 Admire 240F (1 st spray) 1156 ml (88 ml) Admire 240F (2 nd spray) 1178 ml (67 ml) 1178 ml (67 ml) 3

4 All treatments were applied on 15 May Conditions were normal at the time of application (temperature 13 o C, light wind). Precipitation reported by Environment Canada at the Vernon North location 9 : - May 15 maximum temperature 19.5 o C, rainfall none - May 16 maximum temperature 19.0 o C, rainfall none - May 17 maximum temperature 26.0 o C, rainfall none - May 18 maximum temperature 19.0 o C, rainfall 1.9 mm - May 19 maximum temperature 18.0 o C, rainfall 4.8 mm - May 20 maximum temperature 14.0 o C, rainfall 1.2 mm - May 21 maximum temperature 17.5 o C, rainfall none - May 22 maximum temperature 25.5 o C, rainfall none Some treatments required 2 applications at 14-day interval. The second application was made on 29 May Conditions were normal at the time of application (temperature 25 o C, light wind). No precipitation was reported by Environment Canada until June After treatment application, all plants were managed following regular maintenance practices for irrigation and weed control. No other insecticide treatment was made. Growing conditions were typical for the location for the duration of the trial. Evaluations Host tolerance assessments were made at intervals, as required for registration of pesticides in Canada 11. Phytotoxicity assessments were made on 15 May (0 DAT), 19 May (4 DAT), 22 May (7 DAT) and 5 June (21 DAT). At each date, each tree was visually rated for both needles and flower buds, on a 1-unit increment scale of 0 to 10 where 0 was no phytotoxicity, 1 was 1 to 10% of plant surface is affected, 2 was 11 to 20% of plant surface is affected, etc. up to 10 was dead plant. A presence / absence rating was done for specific symptoms typical of pesticide injury such as spots, curling, stunting or necrosis of foliage 12. Cones were collected on June 26 (40 DAT) and July 31 (75 DAT) and delivered at the Kalamalka Research Station for assessment of insect damage by Dr. Ward Strong. At each collection, 10 cones were randomly collected on each treated tree (5 cones from the upper portion of the tree, another 5 cones from around the tree). The cones collected in one tree were placed in a paper bag marked with the site inventory number, stored cool in a storage box, and placed in a room inside the Station main building. Statistical analysis Data is analysed with analysis of variance (ANOVA) with F-test set at p<0.05. Pairwise comparaison with Tukey s HSD is used to establish differences between sample means. 9 Environment Canada Historical Data. Retrieved from y= Ibid. 11 Pest Management Regulatory Agency Efficacy Guidelines for Plant Protection Products. DIR See 12 Costello L.R. et al Abiotic Disorders of Landscape Plants A Diagnostic Guide. University of California, Agriculture and Natural Resrouces. Publication

5 RESULTS FOR PHYTOTOXICITY Damage to needles Data for overall rating of damage to needles is presented in table 3. - Results indicate low level to moderate level of needle damage at 0 DAT. - Results for each treatment did not change appreciably from 0 DAT to 21 DAT. - DAT (Days After Treatment) reflects the date of first treatment application on 15 May. For treatments applied 2 times, the second application was made on 29 May, and the evaluation of 5 June was 7 DAT after the second application. - For all dates, ANOVA indicates no significant treatment effect at p<0.05 (F(9,80)<1.960). Table 3 Mean (and standard deviation) rating of damage to needles, scale of 0 (no damage) to 10 (dead) Treatment 15 May (0 DAT) 19 May (4 DAT) 22 May (7 DAT) 5 June (21 DAT) Untreated control 2.9 (2.3) 3.0 (2.3) 2.6 (1.4) 2.7 (1.7) Dimethoate 480EC 2.2 (1.5) 2.1 (1.8) 2.2 (1.7) 2.1 (1.5) Intrepid 240F (1 spray) 3.1 (2.6) 2.9 (2.5) 2.9 (2.5) 2.8 (2.5) Intrepid 240F (2 sprays) 1.9 (2.4) 1.9 (2.3) 1.9 (2.3) 1.9 (2.3) Delegate WG (1 spray) 2.7 (2.6) 2.6 (2.8) 2.6 (2.5) 2.8 (2.3) Delegate WG (2 sprays) 2.2 (2.2) 2.0 (2.3) 2.1 (2.3) 2.8 (2.5) Movento 240SC (1 spray) 1.8 (1.6) 1.9 (1.8) 1.7 (1.4) 1.9 (1.3) Movento 240SC (2 sprays) 3.2 (2.2) 3.0 (2.5) 2.9 (2.3) 2.7 (2.4) Admire 240F (1 spray) 2.4 (2.5) 2.4 (2.5) 2.3 (2.5) 2.1 (2.4) Admire 240F (2 sprays) 2.3 (1.7) 2.2 (1.8) 2.4 (1.7) 2.6 (1.7) Analysis of variance (p<0.05) MSE=4.8 MSE=5.2 MSE=4.5 MSE=4.5 Comment No significance No significance No significance No significance On needles, specific ratings were made for overall chlorosis, tip chlorosis, overall browning, tip browning and curling of new growth. No significant treatment effect was noted for all ratings. Rating for needle tip browning is presented in table 4. Table 4 Mean (and standard deviation) rating of needle tip browning, presence (1) or absence (0) Treatment 15 May (0 DAT) 19 May (4 DAT) 22 May (7 DAT) 5 June (21 DAT) Untreated control 0.3 (0.5) 0.4 (0.5) 0.4 (0.5) 0.4 (0.5) Dimethoate 480EC 0.4 (0.5) 0.2 (0.4) 0.2 (0.4) 0.3 (0.5) Intrepid 240F (1 spray) 0.3 (0.5) 0.4 (0.5) 0.2 (0.4) 0.3 (0.5) Intrepid 240F (2 sprays) 0.1 (0.3) 0.2 (0.4) 0.2 (0.4) 0.3 (0.5) Delegate WG (1 spray) 0.3 (0.5) 0.2 (0.4) 0.3 (0.5) 0.1 (0.3) Delegate WG (2 sprays) 0.2 (0.4) 0.4 (0.5) 0.4 (0.5) 0.4 (0.5) Movento 240SC (1 spray) 0.3 (0.5) 0.6 (0.5) 0.6 (0.5) 0.4 (0.5) Movento 240SC (2 sprays) 0.4 (0.5) 0.6 (0.5) 0.7 (0.5) 0.4 (0.5) Admire 240F (1 spray) 0.4 (0.5) 0.6 (0.5) 0.6 (0.5) 0.3 (0.5) Admire 240F (2 sprays) 0.1 (0.3) 0.6 (0.5) 0.2 (0.4) 0.4 (0.5) Analysis of variance (p<0.05) MSE=0.2 MSE=0.3 MSE=0.2 MSE=0.3 Comment No significance No significance No significance No significance 5

6 Rating for needle overall chlorosis is presented in table 5. Damage was more pronounced across all treatments as the season progressed, indicating a site-specific condition rather than a treatment effect. Needle tip chlorosis may have been related to nutrient deficiency. On 19 May (4 DAT), ANOVA indicates a significant treatment. However, pairwise comparaison with Tukey s HSD indicates no significance. Table 5 Mean (and standard deviation) rating of needle overall chlorosis, presence (1) or absence (0) Treatment 15 May (0 DAT) 19 May (4 DAT) 22 May (7 DAT) 5 June (21 DAT) Untreated control 0.9 (0.3) 0.9 (0.3) 0.7 (0.5) 1.0 (0.0) Dimethoate 480EC 0.9 (0.3) 0.3 (0.5) 0.1 (0.3) 0.9 (0.3) Intrepid 240F (1 spray) 0.8 (0.4) 0.9 (0.3) 0.6 (0.5) 0.9 (0.3) Intrepid 240F (2 sprays) 0.8 (0.4) 1.0 (0.0) 0.7 (0.5) 0.8 (0.4) Delegate WG (1 spray) 0.6 (0.5) 0.7 (0.5) 0.3 (0.5) 1.0 (0.0) Delegate WG (2 sprays) 0.8 (0.4) 0.6 (0.5) 0.6 (0.5) 1.0 (0.0) Movento 240SC (1 spray) 0.8 (0.4) 0.9 (0.3) 0.4 (0.5) 0.9 (0.3) Movento 240SC (2 sprays) 0.7 (0.5) 1.0 (0.0) 0.9 (0.3) 0.9 (0.3) Admire 240F (1 spray) 0.9 (0.3) 0.8 (0.4) 0.8 (0.4) 0.8 (0.4) Admire 240F (2 sprays) 0.9 (0.3) 1.0 (0.0) 0.6 (0.5) 1.0 (0.0) Analysis of variance (p<0.05) MSE=0.2 MSE=0.1 MSE=0.2 MSE=0.1 Comment No significance No significance No significance No significance Rating for needle tip chlorosis is presented in table 6. Damage was more pronounced across all treatments as the season progressed, indicating a site-specific condition rather than a treatment effect. Needle tip chlorosis may have been related to nutrient deficiency. On 15 May (0 DAT), ANOVA indicates a significant treatment. However, pairwise comparaison with Tukey s HSD indicates no significance. Table 6 Mean (and standard deviation) rating of needle tip chlorosis, presence (1) or absence (0) Treatment 15 May (0 DAT) 19 May (4 DAT) 22 May (7 DAT) 5 June (21 DAT) Untreated control 0.7 (0.5) 0.9 (0.3) 0.9 (0.3) 0.9 (0.3) Dimethoate 480EC 0.9 (0.3) 1.0 (0.0) 1.0 (0.0) 1.0 (0.0) Intrepid 240F (1 spray) 0.9 (0.3) 0.8 (0.4) 0.8 (0.4) 0.9 (0.3) Intrepid 240F (2 sprays) 1.0 (0.0) 0.8 (0.4) 0.7 (0.5) 0.9 (0.3) Delegate WG (1 spray) 0.9 (0.3) 0.9 (0.3) 0.8 (0.4) 0.9 (0.3) Delegate WG (2 sprays) 1.0 (0.0) 0.9 (0.3) 1.0 (0.0) 1.0 (0.0) Movento 240SC (1 spray) 0.6 (0.5) 0.9 (0.3) 0.8 (0.4) 0.9 (0.3) Movento 240SC (2 sprays) 1.0 (0.0) 1.0 (0.0) 1.0 (0.0) 1.0 (0.0) Admire 240F (1 spray) 0.9 (0.3) 0.9 (0.3) 0.9 (0.3) 0.8 (0.4) Admire 240F (2 sprays) 1.0 (0.0) 1.0 (0.0) 0.8 (0.4) 1.0 (0.0) Analysis of variance (p<0.05) MSE=0.1 MSE=0.1 MSE=0.1 MSE=0.1 Comment No significance No significance No significance No significance 6

7 DISCUSSION Life cycle of target pest The Fir coneworm (Dioryctria abietivorella) is a Lepidoptera (moth-like) insect common in Interior Spruce, including at the trial site. Adults emerge from overwintering sites in early May. Location of oviposition is unknown but probably on foliage or bark near the cones. Damage is caused by larvae tunnelling through the cone scales and eating seeds; this damage can occur from June until September 13. Although this is an important pest, there is no pesticide currently registered. Dimethoate applied for other insect pests will help control fir coneworm. Two applications of dimethoate applied at 6 week interval helps control early instar larva. A replacement product would have to target adults during oviposition from contact or residual activity, or eggs laid on the plant surface by ovicidal action, or the newly-hatched larvae from systemic activity. Quality of trial The trial was conducted in a research seed cone orchard in the Interior region of British Columbia. - Environmental and growing conditions were normal for the duration of the project. - All test products mixed well into water. There was no undesirable residue on host foliage. - Application was made for thorough wetting, at the time of adult flight. Phytotoxicity ratings A visual assessment of plant injury was made 3 times following treatment applications. Factors rated were typical of phytotoxicity from pesticide products. - Ratings were done on needles (especially the newer growth) and flower parts. - No treatment-related damage was noted at any rating. Conclusion Based on the location of the trial, method of treatment application and ratings done, all products tested can be applied safety to spruce trees in seed cone orchards. 13 Ruth D.S., G.E. Miller and J.R. Sutherland. Ruth D.S A Guide to Common Insect Pests & Diseases in Spruce Seed Orchards in British Columbia. Publication BC-X-231. Canadian Forestry Service. Victoria BC. Pictures can be viewed from University of British Columbia at the website 7

8 RESEARCH LOCATION Above: Overview of Kalamalka Research Station in Vernon. In the picture, the station can be seen from rows of conifer trees among bare fields. The Station is located on the southern edge of Vernon, in the Interior of British Columbia. Above: Cone flowers on Spruces at the time of application. Bud break was in progress on day of application (shown). The target pest, Dioryctria, had not been captured in traps prior to application. 8

9 PREPARATION OF SPRAY MIXTURE Above: Measure of pesticide Intrepid 240F. A syringe is used to measure 10.0 ml of Intrepid to mix into 10 liters of water. From the mixture, 1.2 liters are measured into a backpack to be sprayed on one tree. Below: Measure of pesticide Delegate WG. A digital scale is used to measure 6.3 grams of Delegate to mix into 15 liters of water. From the mixture, 1.2 liters are measured into a backpack to be sprayed on one tree 9

10 APPLICATION OF TREATMENTS Above: Commercial products applied during this trial. Left to right: Dimethoate 480; Admire 240F; Movento 240SC; Delegate WG; Intrepid 240F. Below: Application of treatment by Sonja Peters on 15 May. A ladder was used to reach the top layers of the trees. Back-pack was refilled for each tree. Most trees received 1.2 liters of spray solution. 10

11 RATING OF PHYTOTOXICITY Above: Rating of spruces for phytotoxicity on 22 May (7 DAT) by Jeanette Merrick. The evaluation is done by the same person at every rating to ensure consistency of method. To help minimize biais, the form displays the site inventory number but not the treatment type. Below: Cone collection by Jeanette Merrick on 26 June (40 DAT). Cones were collected using a ladder and a random pattern around the tree. 11

12 COLLECTION OF CONES Above: Marking of the collection bag. Each bag was labelled with trial number (trial 2 is for spruces) and the site inventory number. Note the bag number does not include a reference to the treatment. Below: For each tree in the trial, 10 cones were collected at random. The bags were then stored in a refrigerator on-site for future examination by Dr. Ward Strong. 12