Criterios de inclusión:

Organic and Integrated Approaches to European Wireworm Control in Atlantic Canada.

K. L. Nelson*, J. L. MacKenzie and A. M. Hammermeister

Organic Agriculture Centre of Canada, Department of Plant and Animal Sciences, Nova Scotia Agricultural College, P.O. Box 550, Truro, NS B2N 5E3

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Background:

Significant losses in crop yield, quality, and marketability have been attributed to wireworms. Control of wireworms through the use of insecticides has proven difficult as most damage occurs after insecticides have lost effectiveness, and many are being deregistered. This has led to the need to develop alternative, integrated strategies that can be employed by both organic and conventional producers.

Project Overview:

Trials were initiated in 2008 to determine (i) crop preferences, (ii) effectiveness of organic deterrents, and (iii) the potential of soil-applied organic immobilization agents against wireworms (Agriotes species) in Nova Scotia. Crop preference trials investigated wheat, corn, red skinned potatoes, and dandelions relative to carrots. Organic deterrents such as marigold, brown mustard extracts and neem oil were tested by treating attractive baits with these deterrent agents in an effort to render the crop unattractive. Soil applied immobilization agents included diatomaceous earth, neem oil and wood ash to cause death or limit wireworm movement and/or feeding. Tests were carried out in plexi-glass chambers filled with a loamy sand soil at ~6% moisture. Wireworms were introduced to the chambers 24 hours after the baits/deterrents/ immobilizations were placed into the chambers, with the wireworm positions and incidence of feeding evaluated 24 hours later. Statistical analysis involved the ‘G’ test for independence for the crop preference and feeding deterrent trials, and an ANOVA for the immobilization experiment.

Results for the crop preference trial suggest that wireworms are more highly attracted to wheat than carrots (Fig. 1). Corn and dandelion did not differ in their attractiveness, while potato was less attractive than carrot. The marigold and

mustard organic deterrents did not significantly alter wireworm feeding behaviour, whereas neem oil resulted in significantly fewer wireworms feeding, as well as fewer occupying the space in the chambers adjacent to neem treated baits. The presence of an immobilization agent did not affect wireworm movement in the soil, nor did they alter mortality or health over a two- month period.

Conclusions:

These trials have resulted in the identification of wheat seedlings as a promising bait crop in carrot production and neem oil as a potential feeding deterrent, however, a successful immobilization agent has not yet been identified. For more detailed information see our technical

bulletins at:

Acknowledgments: Thank you to Nova Scotia Department of Agriculture’s Technology Development Program, the Province of Prince Edward Island, Bragg Lumber, Peter Swetnam (Dominion Produce), Horticulture Nova Scotia and Soil and Crop Improvement Association of Nova Scotia for their support and funding towards this project.

Figure 1: Number of wireworms choosing carrot or various baits (*=significantly different from random choice, p < 0.05).

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Winnipeg, Manitoba February 21-23, 2012

Canadian Organic Science Conference and Science Cluster Strategic Meetings

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Canada's Organic Science Cluster, Activity D.1: Agroecosystem Management for Pest Control in Organic Vegetable Production.

M. L. Leblanc1*, J. Boisclair1, K. Stewart2, D. Cloutier3, M. Lefebvre1, E. Lefrançois1, G. Richard1, G. Moreau1, C. Leyva Mancilla2 and J. Bede2

1. Platform for Innovation in Organic Agriculture, Research and Development Institute for the Agri- Environment (IRDA), Saint-Bruno-de-Montarville, QC.

2. Department of Plant Science, McGill University, St-Anne-de-Bellevue, QC. 3. Agrobyte, Hawkesbury, ON.

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Background:

Few Canadian studies have examined the effectiveness of integrating the use of flowering strips, companion and trap plants and determined their impact on insect and weed populations in organic vegetable production systems.

Project Overview:

The purpose of this project is to investigate how organic vegetable production systems can be managed to increase biodiversity while preventing or minimizing pest problems. This project has been established at the Platform for Innovation in Organic Agriculture in Saint-Bruno-de- Montarville, Québec. It consists of 4 experiments repeated over 2 or 3 years. Crop production methods follow organic agriculture guidelines. Treatments were replicated four times in a complete block design. Each experiment has specific objectives. Experiment 1 was set up to determine the effect of crimper-rolled winter rye on weed control, insect populations and transplanted vegetable crop productivity. The transplanted crops are: A Brassicaceae (broccoli), a Solanaceae crop (pepper), an Alliaceae crop (onion), and a Cucurbitaceae crop (melon/squash).The four treatments are: Crimper-rolled rye, mechanical weeding; hand weeding, and no weeding. Experiment 2 was initiated to study the effect of companion planting of carrots with leeks on crop enemies (insects, weeds and diseases). The nine treatments are: Leek mechanically weeded, hand weeded and not weeded; carrot physically weeded (flaming and mechanical), hand weeded and not weeded; leek and carrot physically weeded, hand weeded and not weeded. Experiment 3 was undertaken to establish the efficacy of trap plants in attracting herbivorous insect populations while decreasing their incidence on the main crop. Yellow rocket and Jimsonweed are used as trap plants in cabbage and potato respectively to decrease the incidence of diamond-back moth and Colorado potato beetle, respectively. The treatments consist of two trap cropping arrangements and crops with no trap. Experiment 4 was carried out to determine the efficacy of different flowering strips in increasing insect biodiversity. The plants evaluated are: Alfalfa, petunia, phacelia, mustard, yarrow, alyssum, coriander, cosmos, French marigold, nasturtium.

Conclusions:

These experiments are ongoing and the results will be integrated in the use of flowering strips, companion and trap plants in organic vegetable production systems when they become available.

Acknowledgments: Thank you to Agriculture and Agri-food Canada (Organic Science cluster program).