Effects of physiological age of seed tubers on seed yield and regrowth of progeny tubers in potatoes

Abstract

SummaryFour experiments are reported in which the effects of a range of physiological ages of seed tubers on growth and yield in seed crops and regrowth of the progeny seed were studied. Increasing the age of seed in Home Guard, Arran Comet, Pentland Javelin and Désirée advanced emergence, tuber initiation and early growth but restricted leaf area index and reduced the number of tubers and seed tuber yield. In these varieties increasing the physiological age of seed shortened the dormancy of the progeny seed and slightly increased sprout lengths at replanting but in Home Guard had no effects on field growth and tuber yield.In a further series of experiments at Tenby seed of five varieties (Home Guard, Red Craigs Royal, Désirée, Maris Piper and Stormont Enterprise) was multiplied over 2 years using husbandry methods designed to produce seed of contrasting ages. Once-grown seed from Tenby which had been planted and harvested early in the season was stored at either 4 or 12 °C and grown again at Tenby before being stored again at either 4 or 12 °C. The seed resulting from this multiplication over 2 years was compared with seed imported from seed-growing areas stored at the two temperatures. The seasons for the two multiplications at Tenby (1975 and 1976) were hot and were followed by an especially cold and late spring yet few differences between seed from Tenby and other areas could be detected. Where seed from different areas entered sprouting temperatures at different times and therefore produced different ages of seed at replanting large effects on yield were found. Storage temperature had large effects on regrowth of tubers in Home Guard, Red Craigs Royal and Stormont Enterprise for storage at 12 °C produced ‘little potato disorder’ in the majority of plants in one storage phase while storage at lower temperature produced full plant stands and yields. The results provided no support for the suggestion that repeated multiplication in warm lowland areas may lead to cumulative deterioration in the performance of seed.