| Abstract: | Biostimulants may enhance the yield and improve crop quality. Scientific reports, however, are still scarce, particularly for the intensive vegetable production area in Egypt. Therefore two field experiments were carried out in the two consecutive seasons in 2009/2010 and 2010/2011. The field trials were performed in sandy soil in the vegetable production in the, area, Giza Governorate (Centre of Egypt). The aim of this work was to evaluate the use of two bio-stimulants for reducing the nitrate content and improving the commercial quality of head lettuce. This study was arranged in a split plot experiment in three replications. The treatments included two nitrogen sources (ammonium nitrate and ammonium sulfate) as main plot and two bio-stimulants (FZB24® and Actiwave®) as sub-plot. The criteria measured were fresh and dry weights of leaves, number of leaves, yield and the contents of nitrogen, nitrate total sugars as well as chlorophyll and carotenoid contents. Results obtained showed that regardless of the nitrogen source, the FZB 24 and Actiwave at both rates significantly increased the leaf number, fresh and dry weights of leaves and the total yield. The highest contents of chlorophyll, total sugars, carotenoids and lower nitrate contents were found in lettuce leaves treated with FZB 24 and Actiwave at the increased rates. The nitrogen source application did not affect the fresh and dry weight of leaves, the yield, the total sugars and chlorophyll contents. Whereas, ammonium sulfate as a nitrogen source significantly increased the leaf number and decreased the nitrate content. Biostimulants exerted a positive role with regard to yield and quality of head lettuce. |
