Comparisons of growth and early yields of potato varieties of contrasting maturity classification at three sites

Abstract

SUMMARYSix experiments which compared a range of contrasting varieties are reported. Two experiments were at a very early, coastal site in N. Pembrokeshire (Trefin), two at a site in South Pembrokeshire (Trefloyne) and two at a coastal site in N. Norfolk (Brancaster). No variety was in every experiment but several were in the majority of experiments. In some experiments sprout growth was manipulated by control of storage temperatures. A variety classified as early or second early produced the highest yields in all experiments but the yields of the best maincrop varieties were high and substantially better than many early varieties. The highest-yielding variety at the first harvest maintained this advantage throughout June and July. At two sites (Trefin and Brancaster) the highest-yielding variety was consistent from year to year but overall the ranking order of varieties for yields was inconsistent, e.g. Arran Comet was the highest-yielding variety at Trefin in both years and one of the lowest yielding at Brancaster.The results suggest that it is unwise to attempt to rank varieties for early yields by an overall score. The maturity classification of varieties is not necessarily an accurate guide to the utility of a variety. A consideration of the physiological age of the seed and growing conditions provided some explanation of these effects and their implication for breeding are discussed.