Assessments of the resistance of potato cultivars and breeder's clones to external mechanical damage

Abstract

SummaryTwenty potato cultivars and breeder's clones were subjected to tests of external damage susceptibility at two sites. At one site tubers were, as in usual agricultural practice, lifted by mechanical harvester, and damage indices were subsequently assigned to each clone. At the other site tubers were harvested by hand on two dates. Drop tests were carried out on this material after 1 week in store and also, in the case of the laterdug (maincrop) material, after 3 months.Ranks based on damage indices were approximately as expected from previous cultivar assessments carried out by other workers. The mean drop test scores showed varying degrees of rank correlation with the damage indices. The highest correlation was with ranks obtained from the drop test on early-harvested material. It was concluded that this was because damage had been inflicted in both cases before skin curing had occurred.