June 23, 2017

Lindsey du Toit -Washington State Commentary – Onion ipmPIPE

onion_flowers

2012 WA Commentary 7-27-2012

 

WASHINGTON and OREGON Columbia Basin Onion Commentary

 

Onion Crop Growth Stage and Status Last Modified: 07/27/12

Crops are at stages 6-7 in Sentinel Plots in the south and north Columbia Basin. The crops look good overall. Some onion seed crops have been swathed and are drying, while others are still in pollination and seed set.

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 07/27/12

July has been hot and surprisingly humid for the Columbia Basin, with frequent thunderstorms. Scattered hailstorms in mid-July resulted in damage to >1,000 acres of onion bulb crops and some onion seed crops. Growers are concerned about secondary infection from bacteria and fungi in hail-damaged crops.

Central Washington temperature outlook (2-4 weeks): 30% above average*

Central Washington precipitation outlook (2-4 weeks): 40% below normal*

* Courtesy of Planalytics, Inc. (http://apps.planalytics.com)

 

Insect Scouting, Outlook and Management Last Modified: 07/27/12

Thrips

Thrips numbers averaged 12-13/plant in the south Columbia Basin Sentinel Plots, and 24-48/plant in Sentinel Plots in the north Basin.

Maggots

No maggot damage this time of year.

 

Other

4% of plants in one of the south Columbia Basin Sentinel Plots had leafminer injury, and 2% of the plants in that Sentinel Plot had green peach aphids.

 

Disease Scouting, Outlook and Management Last Modified: 07/27/12

Iris yellow spot virus

No symptoms in Sentinel Plots.

Soil-borne Diseases (damping-off, pink root, Fusarium, Rhizoctonia)

Pink root observed on 2% of plants in one of the south Basin Sentinel Plots.

 

Fungal Diseases (purple blotch, downy mildew, Botrytis)

Downy mildew observed in several bulb crops in the south Columbia Basin. A drip-irrigated onion bulb crop in the south Basin had symptoms of Botrytis infection in the bulbs, apparently associated with excessive irrigation.

 

Bacterial Diseases (Xanthomonas, center rot, soft rots)

Soft rot was not observed in any Sentinel Plots, but secondary bacterial infection was observed on lower scapes in several onion seed crops with hail damage in the north Columbia Basin, with girdling lesions caused by secondary bacterial infections observed on the lower end of scapes (<5%). Similarly, with >1,000 acres of bulb crops damaged by hail in mid-July, some growers are concerned about secondary bacterial infection in bulb crops.

 


Onion Specialist (submitted on behalf of WA/north-central OR onion participants)

Lindsey du Toit
Associate Professor of Plant Pathology, Washington State University,

Email: dutoit@wsu.edu, 360-848-6140

 

Lindsey du Toit – Washington State Commentary – Onion ipmPIPE

onion_flowers

2012 WA Commentary 6-29-2012

WASHINGTON and OREGON Columbia Basin Onion Commentary

Onion Crop Growth Stage and Status Last Modified: 06/29/12
Overwintered onion crops in the south Columbia Basin are being harvested and appear to have
good yields to date. Spring planted onion bulb crops look good overall. Crop growth is at stages
4-5 in the north Columbia Basin, and 4 to 6 in the south Columbia Basin in the Sentinel Plots.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 06/29/12
Although conditions have been typical in the Columbia Basin for most of June, heavy rains
occurred on 26 June (~1”). In addition, two large, adjacent onion fields south of Warden, WA
suffered significant hail damage from a storm on 24 June (400 acres impacted). Precipitation is
above normal for June.

Central Washington temperature outlook (2-4 weeks): 30% below normal to average*
Central Washington precipitation outlook (2-4 weeks): 30% below average to average*
* Courtesy of Planalytics, Inc. (http://apps.planalytics.com)

Insect Scouting, Outlook and Management Last Modified: 06/29/12
Thrips
Thrips numbers and damage are increasing weekly in the Columbia Basin (severity ratings of 1-2
in the Sentinel Plots).

Maggots
No maggot damage to report this time of year.

Other
Pea leaf miner observed on 4% of the plants in one Sentinel Plot in the south Columbia Basin
(mild symptoms).

Disease Scouting, Outlook and Management Last Modified: 06/29/12
Iris yellow spot virus
Some IYSV present in overwintered onion crops in the south Basin, but nothing significant. No
symptoms in the Sentinel Plots.

Soil-borne Diseases (damping-off, pink root, Fusarium, Rhizoctonia)
Patches continue to show from Rhizoctonia infection in bulb crops on very sandy fields in
the south Basin, planted in rotation with overwintering cereal cover crops that are killed with
herbicides at the time of planting onion seed. No patching evident in the Sentinel Plots.

Fungal Diseases (purple blotch, downy mildew, Botrytis)
A severe case of pink root in the non-fumigated half of a center-pivot irrigated crop in the north
Columbia Basin, compared to mild symptoms in the half of the field that was fumigated prior to
planting. Pink root observed on 2% of plants in a Sentinel Plot in the south Columbia Basin.

Bacterial Diseases (Xanthomonas, center rot, soft rots)
One sample from the south Columbia Basin (Oregon side) that had tip dieback, yellowing, and a

watery appearance on the upper 25% of the leaf was identified by the National Onion Bacterial
Lab as Pantoea agglomerans. Pathogenicity tests were completed by inoculating onion bulbs.
Leaf pathogenicity tests will be completed in July to see if symptoms similar to those observed
on the field sample can be reproduced.

Onion Specialist (submitted on behalf of WA/north-central OR onion participants)
Lindsey du Toit
Associate Professor of Plant Pathology, Washington State University,
Email: dutoit@wsu.edu, 360-848-6140

Onion ipmPIPE Project

onion 2

The ONION ipmPIPE was developed in response to stakeholder demands for a coordinated and comprehensive website where onion farmers and agricultural professionals could obtain: 1) real-time information on the distribution and severity of priority diseases and insect pests in North America; 2) time-sensitive disease risk assessments; 3) information on disease and insect pest management options and 4) links to other important tools on onion production and pest management.   Stakeholders are advised of the status of priority diseases and insect pests through observational maps and national/state commentaries on a public website.  This allows all state commentaries/observations within reach in one website.

Emphasis is on  Onion (green, transplanted, seeded, storage, processed); and other alliums such as garlic & chives benefit from research on pests and diseases.  Priority Diseases and Insect Pests include: Iris yellow spot virus (IYSV); Thrips (emphasis on onion thrips) – as a vector of IYSV and a pest;  Other insects such as onion maggot;  Foliar & storage fungal diseases including Botrytis, Purple Blotch, Downy Mildew, Blue Mold, Black Mold; and Foliar & Storage bacterial diseases including Xanthomonas Leaf Blight, Sour Skin, Slippery Skin, Pantoea, Soft Rots.

A national team of onion experts, growers and industry representatives have created a unique on-line resource that will enhance the production, pest management, storage, and marketing of this vital food product for the consuming public in the United States and internationally.  This multi-year project is funded in part by the USDA’s Specialty Crop Research Initiative established by the 2008 Farm Bill; and has been endorsed by state and national onion organizations throughout all major onion-producing regions of the country.