June 24, 2017

Dan Drost – Utah State Commentary – Onion ipmPIPE

Utah Commentary 8-8


Utah Commentary

Onion Crop Growth Stage and Status Last Modified: 08/8/13

Plant growth considered good to excellent but many fields showing some early maturity (advanced over more normal years). Most fields have bulbs in the 2+ inch size. Growers busy irrigating (no water shortages reported but several noted that irrigation companies preparing for shortages). Transplant fields scheduled to be harvested being in the next week.

Weather Impacts (temperature, rain, hail, freezing) Last Modified: 08/8/13

The Utah weather continues to be very hot with temperatures upper 90’s to low 100’s. Local records continue to be broken. Temperatures above normal expected to continue for the next week to 10 days. No rain reported in last two weeks. Soils moisture considered good as growers continue with irrigation.

Insect Scouting, Outlook and Management Last Modified: 08/8/13


Field surveys on-going. Thrips populations remain high with counts of ranging from 3-15 adult per plant (average 4-5/plant) and 10-120 larvae per plant (average 40-50/plant). Growers are actively spraying to help control thrips. Thrips being controlled adequately when treated with insecticides but fields with high thrips counts associated with growers who purposely do not spray as often.


None reported at this time


None reported at this time

Disease Scouting, Outlook and Management Last Modified: 08/8/13

Iris yellow spot virus

Early indications of IYSV (visual) in storm damaged fields. Some symptoms noted in fields that are more stressed.

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

Pink root found in fields with history of onion production.

Fungal Diseases (purple blotch, downy mildew, Botrytis)

None reported at this time

Bacterial Diseases (Xanthomonas, center rot, soft rots)

Suspected soft rots in hail damaged field which will need confirmation. Onion Specialist Daniel Drost Professor of Horticulture Utah State University Email: dan.drost@usu.edu