This experiment, carried out in a greenhouse from February to May in 2008-2010, was designed to determine the effect of an increased rate of nitrogen and potassium on the content of phosphorus, calcium, magnesium, chlorine and sulphur in basil herbage as well as to trace relationships between a basil cultivar and changes in the mineral composition of the herbage as influenced by the applied rates of nutrients. The mineral composition of basil herbage was determined on the basis of an analysis of the growing substrate conducted after the harvest of the experimental plants. Two Polish cultivars of basil, called Kasia and Wala, as well as a green-leaved form popular on the domestic horticultural market, were grown from seedlings in pots (4 dm3) filled with sphagnum peat of the pH between 5.5-6.0. The following amounts of nutrients were applied, expressed in g per 1 dm3 of the growing substrate: 0.2, 0.4, 0.6, 0.9 N in the form of ammonium nitrate; 0.4, 0.8 K in the form of potassium sulphate; 0.4 P as 20% P superphosphate; 0.3 Mg in the form of magnesium sulphate monohydrate, as well as the following micronutrients (in g per 1 dm3 of the growing substrate): 8.0 Fe (EDTA), 5.1 Mn (MnSO4⋅H2O), 13.3 Cu (CuSO4⋅5H2O), 0.74 Zn (ZnSO4⋅7H2O), 1.6 B (H3BO3) and 3.7 Mo ((NH4)6Mo7)24⋅4H2O). The plants were harvested at the beginning of flowering (29 May 2008, 25 May 2009 and 27 May 2010) by cutting off the aerial part of the stem above its lignified parts. The herbage was dried at 70ºC, ground and used for chemical analysis. The analysed basil herbage proved to be a good source of phosphorus, calcium, chlorine and sulphur. The increasing rate of nitrogen resulted in an increased concentration of the mineral nutrients determined in the basil herbage. The magnesium concentration in the basil herbage dry matter was not dependent on a cultivar and nitrogen rate, but increased under the influence of the higher amount of potassium applied. On the other hand, the raised amounts of potassium did not modify the concentrations of phosphorus and sulphur in the examined plant material.

17.3.2012