الفهرس 
IntroductionOnly 14 pages are availabe for public view
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Abstract
Potato production and product quality are crucial matters for potato customers and growers worldwide. The potentials of producing potato tubers (Burren and Lady Rosetta) cultivars with good qualities using different asexual propagation method stem tip cuttings were investigated in this study in the laboratory and in open field successive summer seasons of 2014 and 2015. The study consisted of two main experiments, the first one studied the production of potato stem cutting-transplants as a propagation method enhanced by growth regulators e.g., Indole-3-acetic acid (IAA) and Indole-3-butyric acid (IBA) in different concentrations along with a positive (rooting powder substance) and negative control (distilled water) substances to stimulate the rooting process. Also, the growth behaviour of these stem cuttings and different growth characteristics, yield and yield component of potato produced by those stem tip cuttings were studied. Results declared that rooted stem tip cuttings could be obtained from only Burren and Lady Rosetta cultivars and propagating potato by stem cuttings as an asexual means of vegetative propagation is very promising. Moreover, all used growth regulators especially in high concentrations resulted in higher values of the most studied characteristics e.g., plant height, plant fresh and dry weights, number of seed – size tubers per plant and total yield per plant comparing to the control treatment. The results of this study may encourage the Egyptian government and potato farmers to use potato stem tip cuttings as a new and cheaper method to grow potato cultivars instead of percentage of the expensive imported seed-tubers for the summer growing season.
The second experiment was carried out to study the effect of gibberellic acid (GA3), indole-3-butyric acid (IBA), garlic extract, yeast extract or green tea extract with different concentrations on potato (Burren and Lady Rosetta) cultivars growth, yield, yield components and chemical composition. Results showed that the applied treatments enhanced potato plants to produce tubers with good qualities and suitable for seed- sized marketing along with decreasing the percentage of small tubers. Also, most of the used treatments increased edible tubers content of NPK and protein within the acceptable ranges for good feeding. The foliar application treatment of these substances was better than that of seed tuber soaking in the same extracts and solutions. Results obtained in this study are very promising for potato farmers under similar conditions and encourage them to use yeast extract at 0.2% or green tea extract at 0.2% as foliar application increasing their seed sized as well as commercial consumed potatoes with good qualities.