Evaluation of PureSpray Green Oil 13E for the management of aphids in wasabi plants

Project Code BPR14-060

Project lead

Jennifer Hayes   Bio-Smart Solutions, British Columbia, Canada

Objectives

Develop efficacy and crop tolerance data in support of a regulatory submission for PureSprayTM GREEN Spray Oil 13E for the management of aphids in wasabi

Summary of Results

Background

During the annual Biopesticides Priority Setting Workshop in March 2013, aphids in wasabi were identified as a priority issue by Canadian growers, and PureSprayTM GREEN Spray Oil 13E (mineral oil) as the desired solution. The product is registered in Canada for control of diseases and insects including aphids in various crops.

Wasabi (Wasabia japonica) is a member of the Cruciferaceae or Brassicaceae family (commonly called the mustard family). It is a perennial plant grown mainly in British Columbia in Canada as a new crop. The rhizome of wasabi has a hot flavor similar to horseradish and is commonly used in sushi restaurants as a condiment.

Aphid (Myzus persicae) is a serious problem in wasabi crop in Canada. There are few pest management products available for control of aphids in wasabi.

In 2015, two efficacy trials (BPR14-061 and BPR14-062) were conducted to develop efficacy and tolerance data in support of a submission of the User Requested Minor Use Label Expansion (URMULE) of PureSprayTM GREEN Spray Oil 13E for the management of aphids in wasabi.

Approaches

Two trials were conducted on wasabi in British Colombia. Treatments in each trial included two rates of PureSprayTM GREEN Spray Oil 13E, insecticide Beleaf 50SG (flonicamid, 50%), which was included as the commercial control treatment, and an untreated control. Each treatment had 4 replicates and 6 applications at 5-7 day intervals except the insecticide Beleaf with 3 applications. Incidences of wasabi plants and leaves infected by aphids, number of aphids per plot, symptomatic severity of plants, and number of fresh marketable leaves per plot were assessed for the efficacy measurements.

Results

In both trials, results showed the two test rates of PureSprayTM GREEN Spray Oil 13E greatly reduced incidence of leaves infested by aphids, number of aphids, and symptomatic severity in the treated plots, compared to the untreated plots. Particularly in the trial BPR14-062, incidences of infested plants and leaves, number of aphids, and symptomatic severity were significantly reduced on most assessment dates and significant control/suppression of aphids was maintained until harvest after the first application. Compared to the untreated controls, aphid number in treated plots with both rates was decreased by 15-83% in the assessment dates in the two trials. The treatments of both rates were able to reduce infested plants by 10-57 and infected leaves by up to 67%. Leaf areas covered by aphids were reduced by up to 87% in the two rate treatments. Plants with curling leaves caused by aphids were reduced by 55-100% in the treated plots in the two trials. Marketable fresh leaves of wasabi were also significantly increased compared with the untreated plots in the two trials. In general, the efficacy levels of the two rates, measured with each of indices, were not significantly different on most of the assessment dates in two trials. No phytotoxicity was observed on wasabi for the product applications in either of the two trials

PureSprayTM GREEN Spray Oil 13E is registered on fruit trees such as apple, pear, peach, plums, blueberry, apricots, and sour cherry in Canada. The data generated from these two trials will be used to support the submission of URMULE of PureSprayTM GREEN Spray Oil 13E for the control of aphids in wasabi in Canada.

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