The Effect of Foliar Nutrition with Nitrogen, Molybdenum, Sucrose and Benzyladenine on the Nitrogen Metabolism in Carrot Plants

Abstract

The Effect of Foliar Nutrition with Nitrogen, Molybdenum, Sucrose and Benzyladenine on the Nitrogen Metabolism in Carrot Plants The Kazan F1 carrot was cultivated in years 2004-2005 in open-work containers sized 60×40×20 cm filled in with silt loam and located on the open field under shade providing fabric. The following combinations of experiments were arranged: (1) control - without foliar nutrition, and foliar nutrition with: (2) urea, (3) solution of urea+Mo, (4) urea+Mo+BA (benzyladenine - BA), (5) urea+Mo+BA+sucrose, (6) BA in the concentration of 5 mg·dm-3 and (7) BA in the concentration of 10 mg·dm-3. In combinations 2-5 the following concentrations of components in solution were applied: urea and sucrose each in 20 g·dm-3, molybdenum 1 mg·dm-3, benzyladenine 5 mg·dm-3. Foliar nutrition was applied three times. In leaves sprayed with urea and with solution of urea+Mo as well as urea+Mo+BA, an increased concentration of NO3 - was observed when compared to other sites. Foliar nutrition did not result in any significant changes in content of N-total and dry weight in leaves. Foliar application of urea, as well as the solution of urea+Mo+BA, caused an increase in the activity of nitrate reductase (NR) in leaves when compared to the control. Whereas, after spraying the plants with BA only, a noticeable decline in NR activity was revealed in comparison with the control; interestingly, a higher concentration of BA (10 mg·dm-3) was more effective. Foliar nutrition with urea+Mo+BA+sucrose and spraying with benzyladenine only (independently from the concentration) resulted in a significant decrease of the content of NO3 - in storage roots when compared to other combinations. The highest level of nitrogen uptake by single storage root and leaves of one carrot plant was found after urea+Mo+BA+sucrose nutrition. In case of N uptake by yield of leaves and biological yield of whole carrot plants (roots+leaves) the highest values were observed in combination no. 6.