EVALUATION OF SPLIT APPLICATIONS OF AUXIGRO® WP PLANT METABOLIC PRIMER AT TWO RATES ON ONIONS IN NORTHERN COLORADO

Dr. Thaddeus Gourd, Extension Agent (Agriculture)

Colorado State University Extension in Adams County. 9755 Henderson Road, Brighton, CO 80601. Phone: 303-637-8117 E-mail: tgourd@co.adams.co.us Web site: www.adamscountyextension.org

Onion quality is determined by a number of factors including size, flavor, storability, and skin retention of the onion bulb. Plant growth regulators have been used in onions for years to improve quality and quantity with mixed results. The purpose of this study was to examine whether two, 4-ounce applications of Auxigro® WP Plant Metabolic Primer or two, 8-ounce applications of Auxigro® WP Plant Metabolic Primer could increase onion size in an on-farm research experiment. The onion variety Sterling was planted on March 6, 2004, on two row beds. Auxigro® WP was first applied at 4 and 8 ounces per acre on July 13, 2004, during bulb swell. The bulb size averaged 1.925 inches in diameter at time of application. Auxigro® WP was again applied at 4 and 8 ounces per acre on August 2, 2004, at which time onion bulb size averaged 2.75 inches in diameter.

Onions were harvested on August 30, 2004. Results showed no significant difference between any Auxigro® treated onions and the untreated check in the number or weight of colossal, jumbo, medium or pre-pack sized onions per plot. Results were analyzed using an analysis of variance with a LSD mean separation. The results of this experiment agree with those of similar experiments conducted in 2002 and 2003.

to the 2004 National Allium Research Conference Home Page