Some effects of seed size and spacing on the yield and grading of two maincrop potato varieties: I. Final yield and its relationship to plant population

Abstract

SUMMARY Two experiments, which investigated the effect of three seed sizes and three withinrow spacings on the graded yield of the two early maincrop varieties Pentland Crown and Maris Piper, are described and the results discussed. Relationships were established between yields in various grades and stem population, and are used to explain the response of yield to changes in seed size and spacing. Comparisons between any two levels of the same treatment were affected by the size grade in which they were made. In addition, the tendency towards interactions between variety and seed size and between variety and spacing suggests that comparisons between varieties are affected by the populations at which these comparisons are made.