June 23, 2017

Dan Drost – Utah State Commentary – Onion ipmPIPE

Utah Commentary 7-11


Utah Commentary

Onion Crop Growth Stage and Status Last Modified: 07/11/13

Plant growth considered normal with onions in growth stages 4-5. Plants are beginning to show bulb sizing in most field. Growers are regularly applying thrips sprays as pest numbers increase. Growers busy irrigating (no water shortages reported but late summer supplies anticipated to be in short supply) and some fields have had hand weeding crews go through them to clean up problem areas. Minor leaf damage occurred in localized areas due to hail.


Weather Impacts (temperature, rain, hail, freezing) Last Modified: 07/11/13

The Utah weather has had been very hot in early July; temperatures upper 90’s to low 100’s (record setting heat continues). Temperatures are about 10 degrees above average. Several days of rain were experienced in early July with strong winds and some localized hail (July 5-6). Soils moisture considered good as growers continue with irrigation. Continued hot dry conditions expected with periodic returns of monsoonal weather patterns (strong winds, heavy rain and possible hail).


Insect Scouting, Outlook and Management Last Modified: 07/11/13


Field surveys on-going. Thrips populations steadily increasing with counts of ranging from 2-12 adult per plant (average 3.5/plant) and 3-35 larvae per plant (average 20/plant). Growers are initiating their personal spray schedules to control thrips.


None reported at this time


None reported at this time


Disease Scouting, Outlook and Management Last Modified: 07/11/13

Iris yellow spot virus

None reported at this time

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

None reported at this time

Fungal Diseases (purple blotch, downy mildew, Botrytis)

None reported at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)

None reported at this time 

Onion Specialist Daniel Drost Professor of Horticulture Utah State University Email: dan.drost@usu.edu