Effect of Manganese Nutrition on Content of Nutrient and Yield of Lettuce (Lactuca Sativa L.) in Hydroponic/Wpływ Żywienia Manganem Na Zawartość Składników I Plonowanie Sałaty (Lactuca Sativa L.) W Hydroponice

The aim of conducted studies was estimation of increase manganese nutrition on content of nutrient and yielding of lettuce (Lactuca sativa L.) in hydroponic cultivation. Plants were grown in rockwool using closed system fertigation with recirculation of nutrient solution. In experiment were used nutrient solution with following nutrient contents [mg·dm^-3]: N-NH4 < 10, N-NO3 150, P-PO₄ 50, K 150, Ca 150, Mg 50, Fe 3.00, Zn 0.44, Cu 0.03, B 0.011, pH 5.50, EC 1.8 mS·cm^-1. It was studied the following manganese concentrations in nutrient solution (in [mg・dm^-3]): 0.5, 4.8, 9.6, 19.2 (described as Mn-I, Mn-II, Mn-III and Mn-IV). It was found a significant influence of increasing manganese concentration applied in fertigation on the content of: N, K (for Mn-IV); P, Fe, Cu (for Mn-III and Mn-IV); Mg, Zn (for Mn-II to Mn-IV) in aboveground parts of lettuce. It was no differences in case of calcium and sodium content. Increasing concentration of manganese used to fertigation significantly influenced the content of Mn in plants. Manganese also affected on the SPAD measurement (decreasing at Mn-IV) and yielding of the plants (decreasing for Mn-II to Mn-IV comparing with Mn-I).