COLE CROPS, ROOTS, BULBS AND LEAFY VEGETABLE EDITION

Prepared by:  Jennifer Allen, Vegetable Crop Specialist

Degree Days

Here are the degree and growing degree-day accumulations for April 1 – May 22, 2009. 

Area	Onion Maggot	Cabbage Maggot	Carrot Rust Fly	Carrot Weevil	Tarnished Plant Bug	Leaf-hopper	GDD
Bradford/ Holland Marsh*	381.9	n/a	332.3	192.5	51.5	122.6	283
Sarnia	371.5	266.9	405.7	224.9	70.5	152.0	325
London	385.4	282.1	422.1	240.0	81.7	166.2	319
Waterloo	327.9	236.8	378.2	197.4	60.5	132.5	279
Windsor	519.7	401.7	547.6	356.6	161.9	271.6	464

1^st generation numbers have been achieved for all pests.  

Degree-day information for pests.

	Degree Days
	1st Generation	2nd Generation	3rd Generation
Onion Maggot	210	1025	1772
Cabbage Maggot	314-398	847-960	1446-1604
Carrot Rust Fly	329 – 395	1399-1711	n/a
Carrot Weevil	138 – 156 455 (90% oviposition)	No model available	n/a
Tarnished Plant Bug	40	n/a	n/a
Aster Leafhopper	128	390	n/a

* Data provided thanks to funding from the Bradford Co-op Storage Ltd., and Muck Crops Research Station, Department of Plant Agriculture, University of Guelph. 

J. Chaput, OMAFRA, Minor Use Coordinator, Guelph

The Pest Management Regulatory Agency (PMRA) recently announced the approval of an emergency use renewal registration for CARZOL SP Miticide-Insecticide (formetanate hydrochloride) for control of onion thrips on dry bulb onions in Nova Scotia, Ontario, Manitoba and Alberta.  Carzol SP Miticide-Insecticide was already labelled in Canada for control of mites and leafhoppers on apples, pears, peaches and nectarines.  In 2008, the emergency use registration of Carzol helped dry bulb onion producers manage this serious pest problem.  Furthermore, a complete minor use submission is under review to seek eventual, full registration of CARZOL for thrips control on dry bulb onions in Canada.

Onion thrips, Thrips tabaci (Lindeman) are a pest of onions around the world.  In Canada, it is considered a key pest wherever onions are grown and the number one pest of onions in most provinces.   Various life stages of onion thrips actively feed on onion leaves, reducing photosynthesis, reducing plant vigour and yield, and vector and transmit Iris Yellow Spot Virus (IYSV). 

In the US, onion thrips were ranked as the number one pest requiring urgent attention due to lack of effective solutions at the 2005 US IR-4 Food Use workshop.  Rapid resistance development to all available, registered materials has become widespread in North America and around the world.  Carzol SP Miticide-Insecticide was identified as a viable solution to help manage onion thrips.  There have been no new products registered in Canada for onion thrips management in several years and control failures continue to increase.  

The emergency use registration of Carzol SP will help in the interim to manage resistant thrips populations; however, management of onion thrips will require a comprehensive IPM and resistance management program with access to all available tools and strategies.  The following is provided as general information only.  Users should consult the complete label before using Carzol SP.     

CARZOL SP Miticide-Insecticide can be used for control of onion thrips in dry bulb onions in Ontario, Nova Scotia, Manitoba and Alberta until October 31^st, 2009 only.  Carzol SP can be applied once at a rate of 1.4 kg product per hectare or Carzol can be applied twice at a rate of 0.84 kg product per hectare at a 7 – 10 day interval.   Do not exceed 1.68 kg per hectare per year.  A minimum spray volume of 94 L water per hectare is recommended and a 30-day pre-harvest interval is permitted.

Follow all other directions for use on the CARZOL SP Miticide-Insecticide label carefully. 

CARZOL SP Miticide-Insecticide should be used in an IPM program and in rotation with other management strategies to manage resistance.

We wish to thank Dr. Jennifer Allen for preparing the rationale documents on behalf of Ontario Nova Scotia, Manitoba and Alberta dry bulb onion growers as well as the personnel of Manitoba Agriculture, Alberta Agriculture and Nova Scotia Agriculture for their input, support and assistance.   We also wish to thank the personnel of the Ontario Ministry of the Environment, Alberta Environment, Manitoba Conservation, Nova Scotia Environment and Gowan Company for their support of this registration and the personnel of the Pest Management Regulatory Agency for evaluating and approving this important pest management tool.  Special thanks are expressed to the Fresh Vegetable Growers of Ontario and Kroeker Farms Limited of Winkler, Manitoba who generously covered the submission fees for this emergency use registration.

For copies of the emergency use label contact Jennifer Allen, OMAFRA Vegetable Crops specialist at Guelph (519) 826-4963, Jim Chaput, OMAFRA, Guelph (519) 826-3539 or visit UAP Canada Inc. www.uap.ca or N. M. Bartlett’s http://www.bartlett.ca/bartlett/default.htm