June 23, 2017

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

Michigan 07282013

  • The most significant problems were the bacterial diseases.

–          Bacterial leaf blight and bulb rot caused by Pantoea agglomerans was detected and confirmed using BIOLOG.

–          Two other types of symptoms were showing 1) the third leaf dead and 2) the newly emerging (center) leaf dead and/or interior rotting of the bulb part.

–          The two unidentified diseases and more bacterial leaf blight and bulb rot samples are being processed and identified.

  • Incidence of pink root and anthracnose has increased.
  • Other fungal diseases were not significant.
  • IYSV was still detected but with low incidence.
  • Thrips populations were low.

 

 

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2013_06_25_Michigan_ipmOnion_Report

 

MICHIGAN Commentary

Onion Crop Growth Stage and Status Last Modified: 06/25/13

Onions have been developing gradually. However, leaf curling at the tip and twisting near the stem base caused by herbicide application have been observed in many fields.

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 06/25/13

In the past two weeks, warm weather has continued. Temperatures across the monitored sites ranged from a low of 43 to 67F with highs ranging from 59 to 88F. Total rainfall amounts ranged from 2.4 to 4.0 inches.

 

Insect Scouting, Outlook and Management Last Modified: 06/25/13

Thrips

Thrips populations have started to increase but are generally low in number. Thrips activity was detected on plants of all growth stages from 3 to 7 leaves.

Maggots

Damage caused by onion maggot has been observed in some fields on direct-seeded onions. Wilting of the foliage was observed along with feeding on the roots. The maggots had burrowed into the basal plate and the creamy-white larva were detected on the roots and basal plate.

Other

None found in surveys or reported at this time

 

Disease Scouting, Outlook and Management Last Modified: 06/25/13

Iris yellow spot virus

Onions with suspected IYSV infection were tested using ELISA and shown to be IYSV positive. Two different types of IYSV symptoms have been observed on plants collected from vaious field sites in southern Michigan. Yellow diamond-shaped lesions and multiple pale green lesions with irregular margins were observed on the onion leaves. Additional symptoms include onions that have green concentric rings within the lesions. Symptomatic onions were collected from fields associated with the occurrence of thrips.

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

Smut incidence has increased. Affected cotyledons and young leaves appear blackened and slightly thickened. Heavy spore production ruptured affected leaves, exposing dark, powdery spore masses. In addition, elongated, black streaks were observed at the stem base of larger plants that survived the infection that occurred at the seedling stage.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

None found in surveys or reported at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)

None found in surveys or reported at this time Onion Specialist Mary Hausbeck Professor and Extension Specialist Michigan State University Email:hausbec1@msu.edu

 

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

05282013_Michigan_ipmOnion_Report

 

MICHIGAN Commentary

Onion Crop Growth Stage and Status Last Modified: 05/28/13

All fields have finished direct seeding by the second week of May. Onion seedlings in the southern part of Michigan were at the one to two leaf stages while onions in the northern fields were flagging.

 

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 05/28/13

Several events of rain and snow were recorded in all planting areas in April. Average temperatures were lows from 29 to 32°F and highs from 64 to 71°F. The areas received 5.87 to 9.08 inches of rainfall for the entire month. Temperatures increased in early May but were followed by windy cold conditions this past week. Total precipitation ranged from 1.16 to 3.81 inches. Frost damage has been observed on the seedlings.

 

Insect Scouting, Outlook and Management Last Modified: 05/28/13

Thrips

None found in surveys or reported at this time

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: 05/28/13

Iris yellow spot virus

None found in surveys or reported at this time

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

Low incidence and severity of smut has been detected on the seedlings at flag leaf and one true leaf stages in some fields.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

None found in surveys or reported at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)

None found in surveys or reported at this time Onion

 

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

 

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

 

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

 

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

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2012_07_26_Michigan_ipmOnion_Report[6]

MICHIGAN Commentary
Onion Crop Growth Stage and Status Last Modified: 07/26/12
Overall onions were at stages 6 and 7 with bulb diameters between 1 and 3 inches. Fields have needed irrigation due to drought conditions.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 07/26/12
For northern sites of Michigan, high temperatures were in the upper 80s to mid 90s. Low temperatures ranged from the upper 60s to 70s. Month to date precipitation was 1.21 inches. For the southern sites, high temperatures ranged from 80s to upper 90s, while low temperatures were in mid 50s to 80s. Total precipitations ranged from 0.76 to 1.45 inches.

Insect Scouting, Outlook and Management Last Modified: 07/26/12
Thrips
Thrips numbers in the northern sites have slightly decreased to the range of 2 to 4 per plant when compared to previous scouting, while the numbers in the southern sites ranged from 2 to 6 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: 07/26/12
Iris yellow spot virus
Monitoring for IYSV revealed that iris yellow spot incidence remained in the fields detected previously. In addition, it has been found in an additional field in a southern site.

Soil-borne Diseases (Damping Off, Pink Root, Fusarium)
Incidence of pink root has been detected in both northern and southern sites. In some sites, the severity appears to be quite high.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

Foliar diseases including anthracnose, purple blotch, and Stemphylium leaf blight have been observed. Disease incidence varied between two regions. Incidence of anthracnose was high in northern sites, while incidence of Stemphylium leaf blight was high in southern sites. Overall, foliar disease severity is lower this season compared to other years due to the drought conditions currently being experienced.

Bacterial Diseases (Xanthomonas, center rot, soft rots)
None found in surveys or reported at this time.

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

Mary Hausbeck – Michigan State Commentary – Onion ipmPIPE

onion-flowers

2012_06_28_Michigan_ipmOnion_Report[4]

MICHIGAN Commentary
Onion Crop Growth Stage and Status Last Modified: 06/28/12

Onions in the southern part of Michigan are at the five-to-eight leaf stage while most onions in the northern fields are at the four-to-six leaf stage.
Weather Impacts (temperature, rain, hail, freezing) Last Modified: 06/28/12
From June 19th to June 27th, for the southern part of Michigan, high temperatures ranged from 80 to 93F and lows from 42 to 79F. For the northern areas, high temperatures ranged from 76 to 88F, while low temperatures ranged from 52 to 76F. Precipitation was average 0.01 inches/day in both sites.

Insect Scouting, Outlook and Management Last Modified: 06/28/12
Thrips
Thrips numbers have increased last scouting period. Numbers of thrips in the northern sites of Michigan ranged from 1.4 to 3.4 per plant, while numbers in the southern sites ranged from 0.56 to 6.56 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: 06/28/12
Iris yellow spot virus
IYSV has not been found in survey plots. However, an IYSV sample was from a field in Grant.
Soil-borne Diseases (Damping Off, Pink Root, Fusarium)
Smut still is still found in northern and southern sites of Michigan. Incidence of pink root has increased in all sites.

Fungal Diseases (purple blotch, downy mildew, Botrytis)
None found in surveys or reported at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)
None found in surveys or reported at this time

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