Effects of plant density and nitrogen fertilization in winter wheat (Triticum aestivum L.). 1. Production pattern and grain yield.

Abstract

Winter wheat cv. Arminda sown on 8 Oct. 1979 at 45 or 125 kg seed/ha was given 60 kg N/ha between 29 Mar. and 23 May at Zadoks growth stage 22, 27, 30, 31, 32 or 37, and a further 80 kg N/ha on 6 June at Zadoks stage 45. Delay in applying N reduced the number of tillers/plant and increased the number of grains/ear but had little effect on number of grains/msuperscript 2, progressively decreased 1000-grain wt and decreased leaf area per plant, per tiller and per msuperscript 2. Higher shoot wt before anthesis was more closely correlated with final grain wt than with grain number. Main stems and side tillers differed in development, growth rate, leaf area, specific leaf area and ear DM content. N uptake was faster the later the N was applied but the efficiency of that N in DM production was reduced and the N content of vegetative plant parts, particularly at low plant density, and of grain was considerably increased. Contents and amounts of water-soluble carbohydrates in stems, leaves and chaff were generally lower at low plant density. Differences in date of N application resulted in different levels and amounts of water-soluble carbohydrates at ripening. (Abstract retrieved from CAB Abstracts by CABI’s permission)