The Effect of Foliar Nutrition with Nitrogen, Molybdenum, Sucrose and Benzyladenine on the Contents of Dry Weight, Cd, Cu and Zn in Carrot

Carrot Kazan F₁ cv. was grown in containers 60x40x20 cm in size, placed on the open site under shadow fabric. The loam clay was used as the substrate, supplemented with the assimilable components to the following levels: 100 mg N, 80 mg P, 120 mg K, 80 mg Mg, 2000 mg Ca·dm^-3 of the soil. In the treatments triple foliar nutrition with the following solutions: 1-control (no foliar nutrition), 2-urea, 3-urea+Mo, 4-urea+Mo+BA (benzyladenine), 5-urea+Mo+BA+sucrose, 6-BA 5 and 7-BA 10 was applied. The concentrations of 20 g·dm^-3 (urea and sucrose), 1 mg·dm^-3 (Mo) and 5 mg·dm^-3 (benzyladenine) were applied in combined solutions, while BA alone was used either as 5 or 10 mg·dm^-3. Foliar nutrition significantly affected dry weight content, Cu and Zn but had no influence on Cd concentration in carrot. The highest content of dry weight was assessed in carrot sprayed with Urea+Mo+Ba+sucrose solution and BA 10. The greatest amounts of Cu were found in storage roots of crops sprayed with Urea+Mo solution, whereas the highest contents of Zn were detected in plants receiving only urea foliar nutrition. A marked effect of interaction of foliar nutrition with the years of research were observed only for Zn concentrations in carrot. Soil of the individual experimental treatments after carrot cultivation differed significantly with respect to its pH reaction and concentrations of readily soluble forms Cd, Cu and Zn.