June 24, 2017

Dan Drost – Utah State Commentary – Onion ipmPIPE

Utah Commentary 7-26


Utah Commentary

Onion Crop Growth Stage and Status Last Modified: 07/26/13

Plant growth considered normal with onions with good top growth but maturity slightly advanced over normal. Most fields have bulbs in the 1½ to 2 inch size. Growers busy irrigating (no water shortages reported but they are anticipated). Most fields have been hand weeded and crews are continuing to clean up problem areas. Fields with leaf damage from localized hail are turning brown (tip drying) due to damage.


Weather Impacts (temperature, rain, hail, freezing) Last Modified: 07/26/13

The Utah weather continues to be very hot with temperatures upper 90’s to low 100’s (record setting heat continues). Temperatures are about 10 degrees above average. No rain reported in last two weeks. 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: 07/26/13


Field surveys on-going. Thrips populations steadily increasing with counts of ranging from 1-11 adult per plant (average 3.5/plant) and 3-104 larvae per plant (average 41/plant). Growers are using their personal spray schedules to control thrips. In general, thrips being controlled adequately when treated though some fields have very high pressure levels and feeding injury.


None reported at this time


None reported at this time


Disease Scouting, Outlook and Management Last Modified: 07/26/13

Iris yellow spot virus

Early indications of IYSV (visual) in storm damaged fields but needs additional confirmation.

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

Pink root noted in two fields in Davis Co (patchy) with history of onion production.

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