Improving growth of date palm plantlets grown under salt stress with yeast and amino acids applications

Egyptian soils are facing a serious problem which is high accumulation of salts for many years of flooding irrigation; thus, it becomes necessary for search about high tolerant crops such as date palm, as well as search for modification agent for these injurious effect of salts on vegetative growth and finally products of crops. This work was done at Central Laboratory of Date Palm for Research and Development at Agriculture Research Centre (ARC), Egypt, to investigate the inversely effects of yeast (Saccharomyces cerevisiae 1 × 109 cells/ml) at 40 and 50 cm/l and amino acids at 3 and 6 cm/l on the bad expression of salinity at two levels 16,000 and 18,000 ppm NaCl + CaCl2 2: 1 by weight on the growth of date palm (Phoenix dactylifera L.) plantlets cv. Bartomouda, chemical compositions as contents of amino acids, chlorophyll a and b, iodole content, uptake of some elements and activated antioxidative enzymes (catalase CAT and peroxidase POD). Results proved that levels of salinity drastically affected plant height (cm), number of leaves/plantlet, and fresh and dry weights (g). Severe reduction was closely associated with 18,000 ppm comparable to the control treatment (without salts), expressive gradually increase in amino acids as well as the content of Na, Ca, and Cl; however, chlorophyll a and b and iodole contents were significantly decreased at two levels, and highest significant reduction was associated with 18,000 ppm salts. Moreover, it was shown that there is a closely positive relation between salt stress and the antioxidative enzyme catalase (CAT) and peroxidase (POD), which was significantly enhanced in the presence of salinity levels, and antioxidant enzymes had the defense system for salt tolerance in a lot of plants. On the other hand, application of yeast and amino acids had significantly ameliorated the harmful effects of salinity, which accompanied by markedly increase in all studied growth parameters particularly at 50 cm/l yeast and 6 cm/l amino acids compared to control treatment (salts only). The tolerance of date palm plantlets to soil salinity could be improved and alleviated the harmful effects of salinity by the application of 50 cm/l yeast or 6 cm/l amino acids to soil.