Comparison of three methods to evaluate fruit firmness in advanced strawberry selections

Fruit firmness is one of the most important factors in the Quebec strawberry breeding program. This characteristic is especially important in fruit varieties that are to be machine harvested or that are destined for out of province markets. The initial firmness test on the first progeny is normally done manually by the breeder. Firmness evaluation of advanced selections is done manually and with the aid of an instrument (Durofel and Lloyd). The objectives of this study were to compare two instrumental methods of measuring firmness (Durofel and Lloyd instruments) in strawberry with the manual method which was done either by an experienced evaluator or a novice (summer student) with a few weeks of training. The two cultivars Bounty and Kent, and four advanced selections from the Quebec strawberry breeding program were used in the experiment. Results showed a significant correlation between the methods tested. However, there was an interaction between the method used and the genotype, which indicated that the level of firmness of a variety depended in part on the method used to measure it. Nevertheless, the results did support the use of the manual method for evaluating strawberry seedlings in field conditions. It also suggested that a novice is capable of estimating firmness manually within a few weeks of training.