Carotenoid pigments in kale are influenced by nitrogen concentration and form

Abstract

The objective of these experiments was to investigate the effects of N rate and form on the accumulation of lutein, β-carotene and chlorophyll pigments in the leaf tissues of kale. Winterbor, Toscano and Redbor kale cultivars were greenhouse grown using nutrient solution culture. In the first study, N treatments were 6, 13, 26, 52 and 105 mg L −1 at a constant 1 NH 4 -N:3 NO 3 -N ratio. On a fresh weight basis, plant pigment concentrations (lutein, β-carotene and chlorophylls) were not affected by N rate. When calculated on a dry weight basis, however, carotenoid pigments increased linearly in response to increasing N rate. In a second study, N rate was held constant at 105 mg L −1 and N form was changed as follows: 100% NH 4 -N:0% NO 3 -N, 75% NH 4 -N:25% NO 3 -N, 50% NH 4 -N:50% NO 3 -N, 25% NH 4 -N:75% NO 3 -N and 0% NH 4 -N:100% NO 3 -N. Increasing NO 3 -N in nutrient solutions from 0 to 100% resulted in increases in both lutein and β-carotene concentrations. Increases in carotenoid concentrations would be expected to increase the nutritional value of kale. Therefore N management should be considered in crop production programmes designed to increase the concentrations of nutritionally valuable carotenoids.

The effect of light and nutrient availability on growth, nitrogen, and pigment contents of Saccharina latissima (Phaeophyceae) grown in outdoor tanks, under natural variation of sunlight and temperature, during autumn and early winter in Denmark

“…The amino acid composition of seaweeds is original and different from that of land plants (Cerna 2011). The synthesis and tissue concentration of high-value components of industrial interest within the biomass (i.e., amino acids, pigments, and antioxidants) increase with nitrogen availability (Gerard 1988;Kopsell et al 2007), and most photosynthetic pigments (e.g., chlorophylls) also increase with decreasing light availability (Bruhn and Gerard 1996;Gomez and Wiencke 1998;Roleda and Dethleff 2011). Concentrations of pigments, such as carotenoids, respond to light availability in a more complex manner, reflecting their accessory as well as photoprotective functions.…”

Minimal nitrogen and water use in horticulture: Effects on quality and content of selected nutrients

“…Once S supply is adequate, however, minimal N applications resulted in highest glucoraphanin content in broccoli (Table 1) (Jones et al, 2007), but N application rates that optimized glucoraphanin content in broccoli resulted in a significant decline in head weight (Jones et al, 2007) In a study with higher N application rates (50-600 kg ha À1 ), Omirou et al (2009) found glucoraphanin content in broccoli florets was maximized with a mid-range N application of 250 kg ha À1 . Growth stress caused by limited N also resulted in enhanced glucosinolate synthesis in pak choi (Shattuck & Wang, 1994), watercress (Kopsell et al, 2007a(Kopsell et al, , 2007b, and cabbage (Rosen et al, 2005) (Table 1). Jones et al (2007) postulated that poor N availability in broccoli florets may indirectly result in an increased availability of methionine for glucosinolate production, as suggested by Dick-Hennes and Buning-Pfaue (1992).…”

“…The most relevant reference is cited. Shattuck and Wang (1994) 14-224 mg L À1 14 mg L À1 Watercress Kopsell et al (2007aKopsell et al ( , 2007b 6-106 mg L À1 56 mg L À1…”

Effects of nitrogen fertilizer and harvesting stage on photosynthetic pigments and phytol contents of Italian ryegrass silage

“…Nitrogen (N) fertilizers can increase the contents of crude protein (CP) and carotenoids (b-carotene) in forages (Kopsell et al 2007;King et al 2012). The contents of CP and carotenoids in grass forages are higher in the early reproductive stage compared with more advanced stages (King et al 2012).…”