Management of sclerotinia rot of carrot using a biofungicide ContansTM and a post-harvest treatment with ScholarTM. V. S. BISHT, T. GONSALVES AND M. DESJARDINS. Manitoba Agriculture, Foods and Rural Initiatives (MAFRI), Crops Knowledge Centre, 65-3rd Avenue N.E., Carman, MB R0G 0J0, Canada; and (M.D.) MAFRI, Crop Diagnostic Centre, 204 - 545 University Crescent, Winnipeg, MB R3T 5S6, Canada
The pathogen, Sclerotinia sclerotiorum (Lib.) de Bary, affects many important crops in Manitoba, including canola, beans, sunflower and vegetables. In carrots, sclerotinia rot disease causes significant economic loss to Manitoba's commercial industry. Field trials were conducted in 2010 and 2011 to study the efficacy of biofungicides Contans™ (Coniothyrium minitans strain CON/M/91-08) and Serenade ASO™ (Bacillus subtilis QST 173 strain) (2010 only) and a post-harvest treatment with Scholar™ (fludioxonil) in managing the disease. In 2010, Contans spore suspension was applied to soil in the spring before planting carrots and one application of Serenade was applied at the recommended rate after 1-month's growth. For carrots planted in 2011, Contans was applied in the spring of 2010 at 0.4 kg/acre before wheat and in the fall at 0.8 kg/acre after the wheat was harvested. The yield data from 2010 and 2011 indicate that Contans reduced sclerotinia infection of carrots in the field; Serenade was not effective in this trial. Post-harvest treatment with Scholar was very effective in reducing carrot rot in storage in 2010; data from the 2011 storage trial will be analysed later. An integrated pest management strategy for sclerotinia rot in carrot could include Contans biofungicide to reduce the potential inoculum, by destruction of sclerotia, and by post-harvest treatment with Scholar.
Reduction of Potato Virus Y spread in potato by mineral oil sprays and regulatory approval for oil applications to potato in Canada. D. MCLAREN, G. BOITEAU, B. ELLIOTT, R. MOHR, M. KHAKBAZAN, J. ISAAK AND D. TOMASIEWICZ. Brandon Research Centre, Agriculture and Agri-Food Canada (AAFC), 2701 Grand Valley Road, Brandon, MB R7A 5Y3, Canada; (G.B.) Potato Research Centre, AAFC, 850 Lincoln Road, Fredericton, NB E3B 4Z7, Canada; (B.E.) Soils and Crops Branch, Manitoba Agriculture, Food and Rural Initiatives, P.O. Box 1149, 65-3rd Avenue N.E., Carman, MB R0G 0J0, Canada; (J.I.) N.M. Bartlett Inc., 4509 Bartlett Road, R.R. 1, Beamsville, ON L0R 1B1, Canada; and (D.T.) Canada-Manitoba Crop Diversification Centre, P.O. Box 309, Carberry, MB R0K 0H0, Canada
Potato Virus Y (PVY) is one of the most important viruses affecting seed potato production as even a low incidence of PVY can cause rejection of seed lots for certification. PVY is spread in a nonpersistent manner by aphid vectors and therefore can be acquired or transmitted in seconds. For this reason, insecticides are generally not effective in reducing PVY spread. In field trials conducted at Brandon, Manitoba (2008--09) and Fredericton, NB (2004--06), the incidence of PVY in potato was reduced with the application of Superior 70 Oil, indicating that the oil provided an effective barrier to PVY. The film of oil applied to the surface of leaves of potato plants restricts virus acquisition or transmission by aphids, thereby reducing PVY spread. Data from these research studies were submitted to the Pest Management Regulatory Agency in support of a user requested minor use label expansion (URMULE) for Bartlett Superior 70 Oil to reduce the spread of PVY vectored by aphids in potato. In June 2011, the addition of the new claim to the label of Bartlett Superior 70 Oil was approved (Reg. No. 9542). This PVY control method represents an additional tool for potato growers to utilize in their efforts to reduce PVY spread in Canadian potato crops.