Relatedness of Bulb Firmness to Other Attributes of New Mexico Onion Entries

Abstract

Harvest of onions in New Mexico is becoming cost prohibitive due to labor shortages and increased labor costs. Mechanical harvest will need to be adopted in order for growers to remain competitive. Onion cultivars, currently grown in New Mexico, need to be evaluated for their suitability to be harvested by mechanical methods. Bulb firmness is one trait that may correlate to mechanical harvest ability of a cultivar. Observations of genetic variation for bulb firmness were taken with an objective to develop cultivars suitable for mechanical harvest. Sixteen short- and intermediate-day onion entries were grown for 2 years and evaluated for bulb firmness and other possible correlated variables. Seedstalks, maturity date, pink root, Fusarium basal rot, percentage marketable yield, average bulb weight, bulb firmness, and single-centeredness were recorded during 2003 and 2004. An instrument, called a durometer, was found to be a reliable tool to measure firmness based upon strong correlation between subjective and objective methods. Single-centeredness and average bulb weight were found to be important factors correlated with bulb firmness.