The influence of fertilization and environment on some nutritionally important quality criteria in vegetables - a review of research in the Nordic countries

Abstract

To understand the phenomena caused by nutrient applications on the quality of vegetables, some research has been done in Finland and in Scandinavia during the last decades. Purpose of this review is to evaluate this data against the information available on genetic and environmental factors. Genotype and light intensity highly affect the vitamin C content of plants. Optimal nitrogen level has a small effect, but excess of nitrogen decreases vitamin C content. Genotype, developmental stage of the plant, adequate photosynthesis, vigorous growth and relatively high temperature increase the carotene content of carrots. The effects of fertilization on the carotene content of plants have been contradictory and warrants more research. No research results could be found of the effects of fertilization or growing practices on the vitamin B content even though vegetables are an important source of vitamin B in diets. Increasing nitrogen fertilization, genotype, low light intensity, low temperature and drought increase the nitrate content of vegetables, but the levels are low in vegetables grown in the Nordic countries, except in lettuce grown under glass with the aid of lights during the dark season. The effect of fertilization on the sugar content is small, and the effect on dietary fibre warrants further study.

Effect of soil compactness on the growth and quality of carrot

“…This is supported also by Simon et al (1982) who showed greater genetic and less environmental variation for sucrose and total sugars. However, the sucrose contents of the present study were slightly lower than reported by Evers (1989b) for the same cultivar.…”

“…ripeness (Fritz and Habben 1974). Also genotype and weather conditions have a clear impact on carrot internal quality (Bradley and Smittle 1965, Simon et al 1982, Miedzobrodzka et al 1993, Evers 1994). Agung and Blair (1989) reported of poor external quality of carrot tap root and decreased fibrous root length density caused by highly compacted soil but, unfortunately, no data on the internal quality were collected.…”

“…The carrot (Daucus carota L.) cultivar grown in these experiments was Nantes Duke Notabene 370 Sv which has been used also in other carrot investigations in the Nordic countries concerning land preparation (Taksdal 1984) and fertilization (Evers 1988). Seeds (in 1989-1990 coated) were sown 1 cm deep and 6 cm wide with a Nibex sowing machine with four units.…”

“…Thus, this relatively large root system consisting of mostly very fine roots in the most fertile soil horizon may be a reason for the insensitivity of carrot yield to water and nitrogen supply in earlier Finnish studies (Lehtinen 1984, Aura 1985, Vuorinen and Takala 1987, Evers 1988 and the ability of carrot plant to grow on soils low in available phosphorus (Itoh and Barber 1983 a). This is not related to root hairs, because carrot root hairs are short (0.04 mm) and have a very limited role in nutrient uptake (Itoh and Barber 1983 a, b.…”

Novel varieties of broccoli for optimal bioactive components under saline stress

“…It has previously been shown that salt stress induces an increase in phenolic compounds as a result of the disturbance caused in secondary metabolic pathways 19, 21, 22. Other authors have also described a decrease in phenolics, and mainly in flavonoids, secondary to extended NaCl treatment 8, 23.…”