Root Maggot Control Trial Rutabga (2009-2012) and Companion Cropping Trial Rutabaga, oilseed mustard and wheat (2010-2012)- 7 pages
ROOT MAGGOT CONTROL TRIAL (2009-2012)
Root maggots (Delia radicum) represent a major problem for growers of vegetable cole crops in Saskatchewan. Maggots damage to the roots renders them less capable of delivering the water and nutrients required for optimal growth. In crops grown for their roots (rutabaga and radish), the scars left by the feeding maggots will render the roots unmarketable. Presently the standard approach to controlling maggots is to apply the insecticide chlorpyrifos (Lorsban) as a root drench on several occasions through the growing season. The timing of chlorpyrifos application(s) is targeted to correspond to the development of the maggot population. Application of chlorpyrifos must cease 30 days prior to harvest for rutabaga. Organophosphates like chlorpyrifos have been targeted for phase-out as soon as effective reduced-risk alternatives are identified.
The objectives of this project were to;
a) test new reduced-risk insecticides for potential use in root maggot management
b) look for alternatives to insecticides as a means to control root maggots
Insecticide Testing
An insecticide testing project was conducted in 2009-2012 at the U of S Vegetable Crops Research Station in Saskatoon. Because of heavy root maggot pressure at this site, the production of vegetable cole crops is difficult – even with repeated applications of pesticides.
Each insecticide treatment consisted of two adjacent rows of rutabaga (cv.
Companion Cropping Trial (2010-2012)
Companion cropping involves mixing two or more crop species within a field in an effort to enhance productivity – with the companion crops “helping” the other crop by repelling insect pests or by providing nutrients.
Root maggot flies identify suitable hosts for egg-laying by a combination of visual cues and odour. The presence of non-host plants in the immediate vicinity of the potential host tends to “confuse” the flies, reducing egg-laying. The flies are attracted by the volatile sulphur-based compounds that give members of the Brassicacea their characteristic odour.
