June 24, 2017

Krishna Mohan – Idaho State Commentary – Onion ipmPIPE

onion bulbs

Onion ipmPIPE 2012 ID State Commentary 07 Sep

Idaho Commentary

 

Onion Crop Growth Stage and Status Last Modified: 09/07/12

Most of the fields are being lifted/topped/harvested. Dry weather conditions are helping with rapid field curing of topped onions

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 09/07/12

Weather continues to be generally hot and dry.

 

Insect Scouting, Outlook and Management Last Modified: 09/07/12

Thrips

Survey of the four sentinel (observation) plots: Average number of thrips (larvae + adults) per plant varied between 197 to 288.  Symptoms of significant thrips damage is evident in many fields.

Maggots 

No surveys or reports at this time

 

Other

No surveys or reports at this time

 

Disease Scouting, Outlook and Management Last Modified: 09/07/12

Iris yellow spot virus

Widespread incidence of IYSV symptoms was observed in all the four sentinel plots.  Medium to high incidence of IYSV symptoms was observed in most of the commercial onion bulb fields, many fields showing premature drying of leaves.

 

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)

Some fields showing areas of significant pink root damage.

 

Fungal Diseases (purple blotch, downy mildew, Botrytis)

No significant problems were observed

 

Bacterial Diseases (Xanthomonas, center rot, soft rots)

No surveys or reports at this time

 

 

 

Onion Pathologist
S. Krishna Mohan
Professor of Plant Pathology
University of Idaho
Email:kmohan@uidaho.edu

 

Howard Schwartz – CO State Commentary – Onion ipmPIPE

onion 2

CO Commentary (09-07-12)

 

COLORADO Commentary

Onion Crop Growth Stage and Status Last Modified: 09/07/12

Thrips pressure is dropping off as plants mature in Eastern, Southern and Western Regions of the state. Risk Models show that Thrips and IYSV are at Mium to High Risk, while foliar bacterial and fungal threats remain at Medium Risk in most regions due to persistent high temperatures and low moisture conditions.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 09/07/12

Most regions of the state received little or no rain in the last week. Temperatures have averaged in the mid 80s to low 90s during the day, and mid 50s to low 60s in the evening.

Temperature Outlook* [2 – 4 weeks]: Normal

Precipitation Outlook* [2 – 4 weeks]: Normal

*Courtesy of Planalytics, Inc.

Insect Scouting, Outlook and Management Last Modified: 09/07/12

Thrips – Populations declining in most fields as plants approach maturity.

Maggots – No reports at this time Other – No other reports at this time.

Disease Scouting, Outlook and Management Last Modified: 09/07/12

Iris yellow spot virus – IYSV detected in surveys of seeded onions (trace to more than 75%) sampled in northern and southern regions.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium) – Pink Root and Fusarium basal rot incidence light to moderate in affected fields throughout the state.

Fungal Diseases (purple blotch, downy mildew, Botrytis) – No reports at this time. Late-season fungicide protection of foliage and necks is recommended for storage rot control; combined with good curing of onions in the field and storage.

Bacterial Diseases (Xanthomonas, center rot, soft rots) – Surveys from all regions detected trace soft rot and leaf blight infections. Late-season bactericide protection of foliage and necks is recommended for storage rot control; combined with good curing of onions in the field and storage.

State Contact for Project Howard Schwartz Professor of Plant Pathology Colorado State University Email:howard.schwartz@colostate.edu

Collaborators: Whitney Cranshaw, Ned Tisserat, Stephanie Szostek, Janet Hardin,

Mike Bartolo, Thad Gourd, Bob Hammon, Colorado Onion Association

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2012_09_06_Michigan_ipmOnion_Report[9]

 

MICHIGAN Commentary

Onion Crop Growth Stage and Status Last Modified: 09/06/12

Remaining crops are very near the harvesting stage. Leaves are drying and bulbs have nearly reached their final size.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 09/06/12

Temperatures have slightly increased. High temperatures were in the upper 80s in a northern site and the 80s to lower 90s in a southern site, while low temperatures ranged in the mid 40s to mid 60s in both sites. A few showers, with 0.55 and 0.95 inch of total rainfall, occurred in all sites in past two weeks.

Insect Scouting, Outlook and Management Last Modified: 09/06/12

Thrips

Roughly 15% incidence of plants with thrips was observed. Each plant had a very low thrips population.

Maggots

None found in surveys or reported at this time.

Other

None found in surveys or reported at this time.

Disease Scouting, Outlook and Management Last Modified: 09/06/12

Iris yellow spot virus

Typical IYSV lesions showing necrotic, diamond-shaped lesions with a green halo have been observed in a field located in a southern site. However, some lesions were not obviously diamond-shaped but were irregular-shaped. This may be caused by multiple infections coalescing into unusually shaped and larger lesions.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)

Pink root has been found in nearly all the fields across the state. Incidence of pink root was very high in every field observed. Above-ground symptoms of pink root are observed as a die-back or a premature senescence of foliage across leaves of all ages. Severely infected plants have reduced bulb size.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

Anthracnose, caused by the pathogen Colletotrichum coccodes, was detected and confirmed. It is widespread in the Grant area. In addition, it was a major problem in the last couple of years within fields across the state.

Purple blotch, a foliar disease caused by a fungus called Alternaria porri, has been found with low incidence. The disease was observed on the plants late in this season, especially after the temperatures cooled down and frequent rain occurred.

Stemphylium leaf blight has been observed more frequently compared to previous scouting. High incidence was observed in onion fields that had experienced hail damage and more frequent rains.

Bacterial Diseases (Xanthomonas, center rot, soft rots)

Fields with these disease problems have been harvested. Some sampling from the bulk crates being stored in the fields has occurred in an effort to explore Michigan’s bacterial disease problem on onions in more depth. Onion Specialist Mary Hausbeck Professor and Extension Specialist Michigan State University Email:hausbec1@msu.edu

 

Dan Drost – Utah State Commentary – Onion ipmPIPE

onion 3

Utah Commentary8-25

 

Utah Commentary

Onion Crop Growth Stage and Status Last Modified: 08/25/12

Onion growth with most fields in growth stage 7 with tops beginning to go down. Transplanted onions are fully harvested. Growers have sufficient water to deal with irrigation needs and continue to irrigate to finish the crop. Growers report that seeded crop harvest should begin around the 1st of September. Most are happy with the growth and sizing should be very good.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/25/12

Warm temperature conditions were experienced over last two weeks. Day temperatures were near normal during the period with temperatures in low to mid 90’s for much of the period. No severe weather experienced (rain, hail).

Insect Scouting, Outlook and Management Last Modified: 08/25/12

Thrips

Thrips populations continue to decrease in all sentinel fields. Final samples taken.

Maggots

None reported at this time

Other

None reported at this time

Disease Scouting, Outlook and Management Last Modified: 08/25/12

Iris yellow spot virus

IYSV incidences found throughout Utah onion production areas with incidence building.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)

Some fields showing patch pink root and basal rot. Left tips dieback evident where PR and BR severe.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

Some minor damage from purple blotch noted but quite isolated at this time. Left tips dieback evident though not always associated with PB.

Bacterial Diseases (Xanthomonas, center rot, soft rots)

Not observed or reported at this time Onion Specialist Daniel Drost Professor of Horticulture Utah State University Email: dan.drost@usu.edu

 

Lindsey du Toit – WA State Commentary – Onion ipmPIPE

onion_flowers

2012 WA Commentary 8-24-2012

WASHINGTON and OREGON Columbia Basin Onion Commentary

 

Onion Crop Growth Stage and Status Last Modified: 08/24/12

Crops are at stage 8 in Sentinel Plots in the south and north Columbia Basin. The crops look good overall. Sentinel plots in the south Basin will be lifted next week, most likely. Fields in the north Basin with the Sentinel Plots received maleic hydrazide applications this week, and all three fields in the north Basin with SPs are starting to senesce (tops beginning to fall over).

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/24/12

Late July and the first half of August have been quite warm in the Columbia Basin (highs in the 90’s to 100’s F), typical for this time of year.

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

Central Washington precipitation outlook (2-4 weeks): average to 30% below average*

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

 

Insect Scouting, Outlook and Management Last Modified: 08/24/12

Thrips: Thrips numbers in Sentinel Plots averaged 3-4/plant in the south Columbia Basin, and 2.8/plant in the north Basin, a continued decline since the last regional report.

 

Maggots: No maggot damage this time of year.

 

Other: Same as last regional report, with 4% of plants in one south Columbia Basin Sentinel Plot having leafminer injury, and 2% of the plants in that plot with green peach aphids. Leafminer damage overall seems worse than previous years in the south Basin. The SPs in all three north Basin fields have two-spotted spider mites, with quite a few in the Moses Lake SP.

 

Disease Scouting, Outlook and Management Last Modified: 08/24/12

Iris yellow spot virus: No symptoms in Sentinel Plots. No further reports from growers either.

 

Soil-borne Diseases (damping-off, pink root, Fusarium, Rhizoctonia): 2% of the plants in one Sentinel Plot in the south Columbia Basin are infected with pink root, as noted in the last report.

 

Fungal Diseases (purple blotch, downy mildew, Botrytis): Symptomatic Botrytis allii (or B. aclada) noted by a grower in south Columbia Basin, but no samples received for confirmation.

 

Bacterial Diseases (Xanthomonas, center rot, soft rots): Symptoms of bacterial soft rot continue to be observed in some overhead irrigated bulb crops in the Columbia Basin, including in one of the Sentinel Plots (as noted in the last report).

 


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

 

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2012_08_24_Michigan_ipmOnion_Report[8]

 

MICHIGAN Commentary

Onion Crop Growth Stage and Status Last Modified: 08/24/12

Bulbs continue to mature with diameters greater than 4 cm. About one third of the scouted fields are topped over, while another third have been harvested from the fields.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/24/12

Growing regions received some precipitation in the form of scattered showers and temperatures are continuing to cool down, especially in the evenings. Dew periods that had been absent for much of this hot summer are now commonly occurring.

Insect Scouting, Outlook and Management Last Modified: 08/24/12

Thrips

Remaining thrips populations were low, with less than a 50% incidence of plants with thrips.

Maggots

None found in surveys or reported at this time.

Other

None found in surveys or reported at this time.

Disease Scouting, Outlook and Management Last Modified: 08/24/12

Iris yellow spot virus

Iris yellow spot virus incidence has been confirmed in both northern and southern sites of Michigan. Obvious symptoms caused by the virus have been observed in the southern site of the state. Managing thrips populations which spread the virus may limit the disease.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)

Pink root has been identified in several fields across the state. Above-ground symptoms of pink root are observed as a die-back or a premature senescence of foliage across leaves of all ages.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

Stemphylium leaf blight appears to be dominant in all fields. High incidence is observed in onion fields which experienced hail damage.

Anthracnose, caused by the pathogen Colletotrichum coccodes, was detected and confirmed. It is widespread in the Grant area.

Bacterial Diseases (Xanthomonas, center rot, soft rots)

Onion leaves presenting symptoms of stalk and leaf necrosis, caused by Pantoea agglomerans, appeared to be in higher numbers compared to the previous scouting date. Identification of the bacteria associated with these recent samples is pending. Onion Specialist Mary Hausbeck Professor and Extension Specialist Michigan State University Email:hausbec1@msu.edu

 

Krishna Mohan – ID State Commentary – Onion ipmPIPE

onion bulbs

Onion ipmPIPE 2012 ID State Commentary 24 Aug

Idaho Commentary

 

Onion Crop Growth Stage and Status Last Modified: 08/24/12

Onion crop development is normal, plants mostly in developmental stage 9 or 10.  Several fields are being harvested. Dry weather conditions are helping with rapid field curing of topped onions

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/24/12

Weather continues to be generally hot and dry.

 

Insect Scouting, Outlook and Management Last Modified: 08/24/12

Thrips

Survey of the four sentinel (observation) plots: Average number of thrips (larvae + adults) per plant varied between 129 to 327.  Symptoms of significant thrips damage is evident in many fields.

Maggots

No surveys or reports at this time

 

Other

No surveys or reports at this time

 

Disease Scouting, Outlook and Management Last Modified: 08/24/12

Iris yellow spot virus

Widespread incidence of IYSV symptoms was observed in all the four sentinel plots.  Medium to high incidence of IYSV symptoms was observed in a most of the commercial onion bulb fields, many fields showing premature drying of leaves.

 

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)

Some fields showing areas of significant pink root damage.

 

Fungal Diseases (purple blotch, downy mildew, Botrytis)

A few bulb samples with side rot (Botrytis gray mold rot) were received in the diagnostic lab.

 

Bacterial Diseases (Xanthomonas, center rot, soft rots)

No surveys or reports at this time

 

 


Onion Pathologist
S. Krishna Mohan
Professor of Plant Pathology
University of Idaho
Email:kmohan@uidaho.edu

 

Dan Drost – Utah State Commentary – Onion ipmPIPE

onion 3

Utah Commentary8-11

Utah Commentary
Onion Crop Growth Stage and Status Last Modified: 08/11/12

Onion bulbing dominates growth with most fields in growth stage 7. Transplanted onions are being harvested (2 weeks early) and seeded onions beginning to show top-down of leaf tissues. Growers have sufficient water to deal with irrigation needs and continue to irrigate frequently due to hot weather conditions. Growers are regularly applying insecticides for thrips control and report minimal damage.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/11/12
Tropical moisture out of SW US dominated weather conditions in Utah. Rain showers are very local and provide less than ½ inch. Day temperatures were above normal with temperatures in hi 90’s for much of the period.

Insect Scouting, Outlook and Management Last Modified: 08/11/12
Thrips
Fifth round of field surveys occurring. Thrips populations are stable or decreasing compared to earlier reports.
Maggots
None reported at this time
Other
None reported at this time

Disease Scouting, Outlook and Management Last Modified: 08/11/12
Iris yellow spot virus
IYSV incidences found in several Utah onion fields but incidence and infection level very low.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)
Some fields showing patch pink root and basal rot.

Fungal Diseases (purple blotch, downy mildew, Botrytis)
Some minor damage from purple blotch noted but quite isolated at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)
Not observed or reported at this time

Onion Specialist Daniel Drost Professor of Horticulture Utah State University Email: dan.drost@usu.edu
Collaborators: Diane Alston, Claudia Nischwitz, Bonnie Bunn and Utah Onion Association

Lindsey du Toit – WA OR State Commentary – Onion ipmPIPE

onion_flowers

2012 WA Commentary 8-11-2012

WASHINGTON and OREGON Columbia Basin Onion Commentary

 

Onion Crop Growth Stage and Status Last Modified: 08/11/12

Crops are at stage 7 in Sentinel Plots in the south and north Columbia Basin. The crops look good overall. Undercutting, topping, field curing, and even harvest have begun for some spring-sown crops in the south Basin. Most onion seed crops have been swathed for harvest.

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/11/12

Late July and the first half of August have been quite warm in the Columbia Basin (highs in the 90’s to 100’s F), typical for this time of year.

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

Central Washington precipitation outlook (2-4 weeks): average (no rain for this region)*

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

 

Insect Scouting, Outlook and Management Last Modified: 08/11/12

Thrips: Thrips numbers in Sentinel Plots averaged 7-12/plant in the south Columbia Basin, and 16-17/plant in the north Basin, a decline since the last regional report.

 

Maggots: No maggot damage to report this time of year.

 

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

 

Disease Scouting, Outlook and Management Last Modified: 08/11/12

Iris yellow spot virus: No symptoms in the Sentinel Plots. Not much to report from commercial crops either, although a few IYSV samples have been received at the Oregon State University Hermiston AREC.

 

Soil-borne Diseases (damping-off, pink root, Fusarium, Rhizoctonia): 2% of the plants in one Sentinel Plot in the south Columbia Basin are infected with pink root.

 

Fungal Diseases (purple blotch, downy mildew, Botrytis): No further incidences since the last regional report.

 

Bacterial Diseases (Xanthomonas, center rot, soft rots): Symptoms of bacterial soft rot were observed in several overhead irrigated bulb crops in the Columbia Basin at a wide range of incidences, including at 1% in one of the Sentinel Plots in the south Basin. Frequent rain events and occasional hail storms in mid-July may have exacerbated bacterial infections.

 


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

 

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2012_08_10_Michigan_ipmOnion_Report [7]

MICHIGAN Commentary
Onion Crop Growth Stage and Status Last Modified: 08/10/12
Vegetative phase of most onions have nearly reached the end as the outer leaves have continued to dry out. Some early varieties have started to top over.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/10/12
Several events of scattered rain have occurred. Total rainfall in past two weeks across the monitored sites was generally between 0.72 and 1.32 inches. Temperatures in the northern sites were high from 69 to 93F and low from 54 to 71F, while temperatures in the southern sites were high from 72 to 95F and low from 49 to 71F.

Insect Scouting, Outlook and Management Last Modified: 08/10/12
Thrips
Average thrips numbers were low in some areas with one to two per plant since as an insecticide was sprayed a few day prior to the scouting. However, thrips numbers in one field located in the northern site was high with 19 per plant.
Maggots
None found in surveys or reported at this time.
Other
None found in surveys or reported at this time.

Disease Scouting, Outlook and Management Last Modified: 08/10/12
Iris yellow spot virus
Iris yellow spot virus was found in a site reported previously with the incidence appearing to increase; more diseased plant have been detected.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)
Smut has been identified in more mature plants showing dark spores forming in the leaf whorl and scale tissues. The dieback of the foliage as a result is obvious.
High incidence of pink root has been found in nearly of all the scouted fields. Aboveground symptoms show the dieback of the leaf tips. Small bulbs have formed on these stunted plants. Below ground symptoms indicate severe infection and damage to nearly the entire root system.

Fungal Diseases (purple blotch, downy mildew, Botrytis)
Stemphylium leaf blight was prevalent in many sentinel plots, while other foliar diseases including purple blotch and anthracnose have been found at low incidence.

Bacterial Diseases (Xanthomonas, center rot, soft rots)
Stalk and leaf necrosis (or leaf blight and bulb rot) caused by Pantoea agglomerans has been recently detected at a damage level of 2 out of 5 (~8%) in a field at the southern site. Symptoms include blighting and withering on the leaves. In addition, infected leaves appear to be watersoaked.

Onion Specialist Mary Hausbeck Professor and Extension Specialist Michigan State University Email:hausbec1@msu.edu