Effects of Different Sources and Fertilizer Rates on the Lettuce Yield and Quality under Controlled Conditions

N. Poushkarov Institute of Soil Science, BG-1080 Sofia, Bulgaria


STANCHEVA, I. and I. MITOVA, 2002. Effects of different sources and fertilizer rates on the lettuce yield and quality under controlled conditions. Bulg. J. Agric. Sci., 8: 157–160

Lettuce plants (Lactuca sativa L.) were grown in a controlled environmental chamber in 1 kg plastic pots contained glasshouse soil substrate until technical maturity stage. Plants were grown at three fertilizer sources: mineral fertilizez, farmyard manure and foliar fertilization. Mineral and organic fertilizers were applied at three fertilizer rates. The most favourable effect on the plant biomass accumulation showed fertilizer rates of 100 mg/kg mineral nitrogen and 4.2 g/kg farmyard manure. A beneficial effect of foliar fertilizer Agroleaf on the lettuce development and produce quality was observed: high values of fresh and dry biomass and reduced nitrate content.

Key words: lettuce, mineral fertilizers, organic farmyard manure, foliar fertilizer, fresh lettuce quality