Leaf Growth and Chlorophyll Content of Oilseed Rape (Brassica napus L.) as Influenced by Nitrogen Supply

Abstract

An experiment was conducted using a greenhouse hydroponics system to investigate the influence of N nutrition on leaf growth and chlorophyll content in oilseed rape (Brassica napus L.) during both vegetative and generative growth. Plants were treated continuously with one of three levels of N supply (30, 100 or 170ppm N). Leaf expansion in terms of lamina area of individual leaves and leaf area per plant, and chlorophyll content of leaves during both growth phases were increased significantly by N supply up to 100 ppm N, which was found to be the optimum level for oilseed rape. N supply of 30 ppm N resulted in N stress while 170 ppm N represents an excessive supply. N supply of 100 ppm N enhanced leaf expansion during H–6 weeks after transplanting by 88–260 % over that of 30 ppm N. Lamina areas of younger leaves responded to N nutrition better than did those of older leaves. Leaf area per plant increased 155–194 % due to increasing N supply but leaf number was increased less remarkably (by 25–44 %). N supply enhanced the contents of leaf chlorophyll a, chlorophyll b, and total chlorophyll but had very little influence on chlorophyll a/b ratios; except that increasing N supply tended to reduce these ratios. Results suggest that variation in leaf chlorophyll content of rape plants in response to N nutrition is a function of leaf age and position. The significance of these results in terms of certain physiological implications for the rape plant is discussed.

Effect of nitrogen fertilization on nitrogen dynamics in oilseed rape using 15N‐labeling field experiment

“…It has been shown that the principal effects of increasing N status in Brassica napus include an increase in leaf number and area (Allen and Morgan, 1972;Gammelvind et al, 1996;Leleu et al, 2000;Svecnjak and Rengel, 2006;Wright et al, 1988;), leaf chlorophyll content (Ogunlela et al, 1989), and pod number and area (Allen and Morgan, 1972;Gammelvind et al, 1996;Hocking et al, 1997;Leleu et al, 2000;Taylor et al, 1991). Because crop N uptake mostly occurs prior to pod development, the yield response of oilseed rape to N fertilization will depend, in part, on the capacity of the crop to remobilize N from senescing vegetative organs and to transfer this N to developing seeds.…”

Effect of Timing and Nitrogen Fertilizer Application on Winter Oilseed Rape (Brassica napus L.). II. Nitrogen Uptake Dynamics and Fertilizer Efficiency

“…2001). All vegetative plant parts, especially leaves, increase their weight and chlorophyll content with increasing soil and fertilizer N supply (Ogunlela et al. 1989, Gammelvind et al.…”

Photosynthetic variation and photosynthetic nitrogen use efficiency in Brassica species with different genetic constitution of ribulose-1,5-bisphosphate carboxylase

“…Other factors such as leaf mass per area (LMA) or partitioning of dry matter to stem may also affect pNUE (Brown and Wilson 1983). At the biochemical level, high N supply increased leaf protein and chlorophyll (Chl) contents and content of several enzymes involved in CO 2 fixation (Wong 1979, Hesketh et al 1981, Girardin et al 1985, Evans 1989, Ogunella et al 1989.…”