OMAFRA Apple IPM Projects Update 2007

This past growing season was a busy year for IPM projects in apples. Fortunately with funding and support from several chemical companies, the pest management centre, Hort Crops Ontario, and the Ontario Apple Growers we have been able to get a lot done this year.

The following are a list of some of the products initiated this year:

OMAFRA led projects in apple IPM

• Evaluating the efficacy of Rimon (novaluron) and Altacor (rynaxapyr) in managing obliquebanded leafroller (K. Carter, M. Appleby) (funding from Chemtura, Dupont and OAG). Rimon (novaluron) is an insect growth regulator (IPM friendly insecticide) that was registered in 2007 for use on apple against a variety of insect pests (codling moth, oriental fruit moth). Research in the US has shown that this product can provide effective control of obliquebanded leafroller populations when applied at petal fall in apple orchards. Altacor (rynaxypyr) is a new chemistry of insecticide that is also considered to have good efficacy against obliquebanded leafroller. Submission has been made for the registration of Altacor^™ for the control of pests like oblique-banded leafroller, codling moth, oriental fruit moth, and spotted tentiform leafminer.  The goal of this project was to compare the efficacy of these two new insecticides to Intrepid (methoxyfenozide) another product that is already registered for obliquebanded leafroller. Insecticides were applied at petal fall and were re-applied 10-14 days later. Although the data has yet to be analyzed, all of the products provided good control of leafrollers. None of the products appeared to have a negative impact on phytophagous mites (european red mite and two-spotted spider mite) populations.
• Evaluating miticides in managing mite populations (K. Carter) A project was initiated to compare the efficacy of high and low rates of application of Acramite to manage european red mites in Ontario apple orchards. The results of this trial have yet to be analyzed.
• Evaluation of the use of mating disruption in managing the apple clearwing moth (Synanthedon myopaeformis). (Project lead: H. Fraser; collaborators: D. Beaton, K. Carter, N. Carter). The apple clearwing moth (Synanthedon myopaeformis) was first noted in BC in 2005, and a single orchard with this pest was found by the CFIA in Ontario in 2006. Surveys in 2007 found that although this pest is still present in relatively high numbers at one orchard in Ontario it has not been found at any other orchards. The goal of this project is to work with the grower to implement mating disruption to manage this pest. This is the first year of a multi-year project.
• Evaluation of the use of Calypso (thiacloprid) in managing early season pests of apple (K. Carter, M. Appleby) The goal of this demonstration trial was to get a better understanding of how Calypso fits into our existing apple IPM program. Petal fall applications of Calypso were used to evaluate the efficacy of this product against mullein bug, and oriental fruit moth. Two orchard blocks were set up, one that received Calypso and another that received a conventional treatment. Monitoring for aphids, leafhoppers, and mullein bugs was conducted prior to spray application and June 5th. The results of this demonstration trial suggest that Calypso was effective in managing mullein bug populations, aphids, and oriental fruit moth.
• Evaluation of black rot in Royal Gala apples in response to chemical thinning (funding from HCO) (Project leads: M. Celetti, J. Gardner and J. Cline, collaborator: K. Carter) A preliminary study in 2006 indicated that the application of chemical thinners Fuitone and Maxcel at petal fall may result in less black rot infected fruit caused by Botryosphaeria obtusa at harvest but may not be optimum for reducing fruit load and maximizing fruit size. A second experiment was conducted in 2007 to further investigate the effect of timing of the chemical thinners Fruitone and Maxcel on the incidence and severity of black rot on fruit and to compare these treatments with hand-thinning. The incidence of black rot was lower on fruit from trees that were thinned when developing fruit were 6-8 mm in diameter than from trees thinned when developing fruit were 12-14 mm in diameter. Hand thinned trees had significantly fewer mummified fruitlets and a lower incidence of black rot infected fruit at harvest, in comparison with trees that were chemically thinned. Best thinning was observed when treatments were applied to trees when developing fruit were 6-8 mm or 12-14 mm in diameter. Trees that received 6-BA had significantly fewer fruit than trees that were hand thinned. Applying chemical thinners when developing fruit were 6-8 mm in diameter reduced the crop load, maximized fruit size and minimized black rot infected fruit at harvest.
• Validation of an oviposition model for timing insecticide sprays against plum curculio (PC) in Ontario (funding from HCO) (Project lead: H. Fraser, collaborators: K. Carter, M. Appleby) This preliminary study will validate the usefulness of the NY PC model under Ontario growing conditions and will help growers improve pesticide timing and reduce unnecessary pesticide use. OMAFRA staff will evaluate the effectiveness of two types of traps for monitoring PC in apple orchards. Weather data will be collected at each site and incorporated into the NY model to predict insect emergence and time insecticide sprays. Traps will be used to monitor insect activity in several orchards. OMAFRA staff will use two different types of insect traps at 9 orchards throughout Ontario to monitor PC populations and evaluate the accuracy of the traps in monitoring pest populations. We have preliminary data from this project in 2007, and are hoping to continue on this research in 2008.
• Refinement of a developmental model for obliquebanded leafroller and insecticide timings using new, reduced-risk pest control products (funding from HCO) (Project lead: H. Fraser, collaborators: K. Carter, M. Appleby) This study will track both the flight patterns of OBLR adults and compare predictive models with observed insect lifestages (eggs, various instar larvae, pupae) present in the field. OMAFRA staff will place pheromone traps in several orchards and monitor weather conditions in eight sites throughout Ontario. The Ontario model will be compared to more sophisticated models to determine the most accurate model for predicting insect development in Ontario. We have preliminary data from this project in 2007, and are hoping to continue on this research in 2008.

Projects led by other researchers, in which OMAFRA participated:

• Evaluating the use of GF 120 (spinosad+bait) in managing apple maggots in Canada. (Project lead: J. Reekie, AAFC-Kentville, NS), collaborators: K. Wilson/Lindsay Pink private consultant; K. Carter, Appleby, and H. Fraser, OMAFRA ) (funding from PMC and OAG) The objective of this project was to evaluate the efficacy of GF 120 a spinosad bait in managing apple maggot in organic apple orchards. In Ontario, two organic ‘Novaspy’ orchards were used for the evaluations, while in Nova Scotia three organic and one IFP orchards (‘McIntosh’, ‘Cortland’, ‘Rhode Island Greenings’ and a seedling mix orchard) were used. In each orchard there were four replications of four treatments and a control. Treatments included three rates of GF-120: 1x, 1.5x and 2x label rate and Surround. Insecticide treatments were applied on a weekly basis following capture of the first adult apple maggot on a yellow sticky board. Harvest assessments were conducted in September to evaluate the different treatments. During harvest assessments 20 apples were collected from 10 trees in each plot; in control plots 20 apples from 16 control trees. Fruit were incubated at room temperature for 2 weeks. Fruit were cut into quarters and apple maggot damage was recorded. Based on the findings of this study, it can be concluded that GF-120 is as effective as Surround in the control of apple maggot. Therefore, it is recommended that GF-120 be used to control apple maggot in organic and conventional orchards.