EFFECT OF WATER STRESS AND FERTILIZATION WITH INORGANIC NITROGEN AND ORGANIC CHICKEN MANURE ON VEGETATIVE GROWTH CHARACHTERS OF POTATO

Two field experiments were performed at the Experimental Station, Faculty of Agriculture, MansouraUniversity during the two successive summer seasons of 2007 and 2008. This investigation was aimed to study the effect of water tension treatments, mineral of nitrogen and organic fertilizers combinations and their interactions on vegetative growth characters of potato (Solanum tuberosum L.) cv. Spunta. Each irrigation treatments was conducted in a separate experiment. Every separate experiment laid-out in randomized complete block design with four replicates.
The main results of this investigation could be summarized as follows:
1-The results indicated that there was a significant effect on plant height, leaf area/plant, number of stems/plant, fresh and dry weights of plant foliage as well as total chlorophyll content as a result of irrigation tension in both seasons, except plant height in the first season only. However, irrigation tension did not affect number of leaves/plant in both seasons. Irrigation at 26cb (5360.17 m³ water/ha) i.e. 54.1% moisture from field capacity produced the highest averages of plant height, number of leaves and stems/plant, leaf area/plant, fresh and dry weights of plant foliage in both seasons. While, irrigation at 22cb (6209.32 m³ water/ha) i.e. 59.3% from field capacity recorded the highest averages of total chlorophyll content in both seasons.
2- Fertilization treatments had a significant effect on all studied characters during both seasons. Application of 60% inorganic nitrogen fertilizer (238 kg N/ha) + 40% organic chicken manure (158 kg N/ha) markedly recorded the highest values of these characters, except chlorophyll content which resulted from application of 100% mineral nitrogen fertilizer (396 kg N/ha) as compared with other fertilization treatments.
3- The interaction between studied factors had a significant effect on plant height, leaf area/plant and number of stems/plant in both seasons as well as fresh weight of plant foliage in the second season. Irrigation at 26cb (5360.17 m³ water/ha) i.e. 54.1% moisture from field capacity in addition fertilization with 60% inorganic nitrogen fertilizer (238 kg N/ha) and 40% organic chicken manure (158 kg N/ha) markedly recorded the highest averages of these characters as compared with other fertilization treatments.