Effect of nitrogen fertilizer applied to the seed crop on the subsequent growth of early potatoes

Abstract

SummaryThree experiments involving three early maincrop cultivars explored the effect of nitrogen fertilizer (0–301 kg N/ha) applied to seed potato crops on seed performance and the growth of the subsequent early ware crop.The tuber N-content ranged from 1·1 g N/100 g dry matter (D.M.) to 1·6 g N/100 g D.M. for seed tubers obtained from crops grown at 0 and 201·301 kg N/ha. Seed of cv. Maris Peer from crops given 100 kg N/ha in 1969 produced ware yields 10% and 24% higher than those obtained from seed from crops given 0 and 201 kg N/ha. No effects of fertilizer applied to the seed crop on subsequent growth were observed in the other two experiments.It is suggested that the effects of nitrogen fertilizer applied to the seed crop on subsequent growth other than that related to seed tuber size only arise as a result of effects on the maturity of the seed crop. Thus any observed effect is attributed to differences in the ‘physiological age’ of seed rather than to differences in seed tuber N-reserves.