Essential oils formulations for the control of mites, insects, and diseases on greenhouse ornamental and vegetable crops
Project Code : BPI06-120
André Bélanger - Agriculture and Agri-Food Canada
To optimize and field test terpene formulations for use as broad spectrum control agents against key pests and diseases in tomato, cucumber, green pepper, lettuce and grapes
Summary of Results
Terpenes, like pyrethroids are natural defence components of botanical essential oils. Pure synthetic terpenes are highly effective against a wide range of plant pests and diseases although synergistic mixtures are most effective.
The greenhouse vegetable and ornamental industry is an important growing segment of the Canadian agri-food industry. One of the few insecticides available for use on vegetable crops in greenhouses is the spinosad-based insecticide Success which is effective against Lepidopterans, and thrips, but not against aphids, whiteflies or spider mites. Recently, insecticides based on plant essential oils have been developed in the USA. Plant essential oils have been long been used in perfumes and foods, and are now being used for the development of reduced risk pesticides. Essential oil-based insecticides are considered relatively safe to humans and mixtures of essential oil constituents have been proven to be effective against many insects. EcoTrol EC® is one such broad-spectrum insecticide based on rosemary oil as the active ingredient.
Tests were performed in BC greenhouse vegetable crops (tomato, peppers and cucumber) to examine the effect of a EcoTrol EC® against the greenhouse whitefly (Trialeurodes vaporariorum), green peach aphid (Myzus persicae), two spotted spider mite (Tetranychus urticae) and cabbage looper (Trichoplusia ni) on tomato, pepper and cucumber crops in British Colombia. The efficacy of three concentrations of EcoTrol EC® was compared to a blank formulation of EcoTrol EC®, a water control, and the insecticide, Success. EcoTrol EC® showed some efficacy against aphids and mites on tomato and pepper plants, however, its effect was no better than the spinosad product. Furthermore, when tested against cabbage loopers and whitefly eggs, EcoTrol EC® showed little or no effect whereas Spinosad proved to be efficacious, as expected.
Greenhouse tests were also performed in Québec on ornamental plants against the greenhouse whitefly and green peach aphid on Petunia, the two spotted spider mite on New Guinea impatiens and hibiscus, and on two species of thrips, Frankliniella occidentalis Pergande on chrysanthemum and Echinothrips americanus Morgan on hibiscus. As in the case of the BC studies, the three concentrations of EcoTrol EC® showed some efficacy against aphids and mites, however, its effect was not greater than that of Spinosad. Furthermore, there was no significant difference among treatments on the egg development of the greenhouse whitefly. EcoTrol EC® showed little or no effect whereas Spinosad proved to be effective. The effect of the treatments on nymphs and adults of the two-spotted mite on New Guinea impatiens plants varied among trials and are not significant. On hibiscus plants, it was observed that among all the treatments on the two-spotted mite, the highest concentration of EcoTrol EC® (10ml/L) provided the highest mortality 48 and 96h after the treatments. The two most effective treatments to reduce the abundance of the Western flower thrips were Spinosad and EcoTrol EC® at a dose of 10ml/L.
In conclusion, EcoTrol EC® was found to be somewhat effective against aphids and mites on tomato and pepper plants, and on some ornamentals, although some phytotoxic effects were observed at the highest rate of EcoTrol EC® on chrysanthemums. No efficacy against cabbage loopers and whiteflies was demonstrated by these trials.
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