THE INFLUENCE OF FERTILIZATION AND ENVIRONMENT ON SOME NUTRITIONALLY IMPORTANT QUALITY CRITERIA IN VEGETABLES - A REVIEW OF RESEARCH IN THENORDIC COUNTRIES

To understand the phenomena caused by nutrient applications on the qua lity of vegetables, some research has been done in Finland and in Scan dinavia during the last decades. Purpose of this review is to evaluate this data against the information available on genetic and environmen tal factors. Genotype and light intensity highly affect the vitamin C content of plants. Optimal nitrogen level has a small effect, but exce ss of nitrogen decreases vitamin C content. Genotype, developmental st age of the plant, adequate photosynthesis, vigorous growth and relativ ely high temperature increase the carotene content of carrots. The eff ects of fertilization on the carotene content of plants have been cont radictory and warrants more research. No research results could be fou nd 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 inte nsity, low temperature and drought increase the nitrate content of veg etables, but the levels are low in vegetables grown in the Nordic coun tries, except in lettuce grown under glass with the aid of lights duri ng the dark season. The effect of fertilization on the sugar content i s small, and the effect on dietary fibre warrants further study.