Inter-plant variation of grain yield components and kernel composition of maize crops grown under contrasting nitrogen supply

摘要: Abstract High intra-specific competition pressure, which is common at most maize ( Zea mays L.) cropping conditions, promotes inter-plant variation and the appearance of extreme plant hierarchies with different ability to capture scarce resources (i.e., dominant dominated plants) within a stand. The objectives current work were analyze (i) grain yield per (GYP), GYP components (KNP: kernel number plant; KW: weight), composition, together those their physiological determinants, i.e., growth (PG) rate around silking (PGR S ), PGR  KNP −1 ) PG during effective grain-filling period (PG GF under contrasting N supply (ii) contribution plants changes in mean values studied traits. For these purposes two hybrids previously characterized by stress (low: AX820 high: AX877) cultivated high stand densities (9 12 pl m −2 supplies (N 0 : control 200 200 kg N ha without water restrictions. AX820, data set both levels explored similar range (1–7.4 1.2–7.4 g pl  d for , respectively) positive skewness an almost normal distribution . In contrast, AX877, exhibited levels, fertilization only produced displacement higher (0–4.3 0.7–5.7 g pl respectively). effect on coefficient (CV) KNP was greater magnitude AX877 than due more linear response former. hybrids, KW increased CVs decreased supply. Differences among related duration period. Inter-plant protein starch concentrations but that oil concentration not affected analysis resulted useful understand frequency distributions several agronomic