Interactive effect of some different seawater dilutions, remediation treatments at different growth stages of celery plants on 1- vegetative growth and quality parameters

For facing acute problem of fresh water scarcity in the future, also, the sharing part from the Nile fresh water is 55.5 milliar mþ. 3. This amount cannot be increased. In turn, there is no an increase of the available water for cultivation of newly reclaimed lands or face increasing population. So, two pot experiments were conducted in the open field of Agriculture Station, Mansoura University during the two successive winter seasons of 2006-2007 and 2007-2008. To evaluate the growth and quality characteristics of celery (Apium graveolens var dulce), cv. Victoria plants, in response to different seawater dilutions and some remediation treatments as well as salinization regime at different periods and their interactions. Factorial experiment in a randomized complete block design was used with 4 replicates for each treatment. The experiment included 90 treatments: 6 treatments of seawater dilutions with Nile water (Control, 5% seawater, 10% seawater, 15% seawater, 20% seawater, 25% seawater), 5 remediation treatments (without, Calcium 5mM(Ca1),Calcium 10 mM (Ca2), Polymer+Ca1, Polymer+Ca2). and 3 treatments of salinization regime ( after 20, 40, 60 days from transplanting). The results indicated that the effect of increasing the level seawater salinity from 5% up to 25% significantly decreased the mean values of plant growth parameters comparing with the control treatment (fresh water). Also, N02-N and NO3N concentrations were decreased significantly with increasing salinity levels. However, Vit C and TSS concentrations were increased significantly with increasing water salinity. Soil application with polymer combined with Ca2 was superior for increasing the most values of plant growth parameters, Vit C and TSS concentrations of celery plants following by foliar spraying with solution contains Ca (10 mM). While, both N02-N and N03-N decreased significantly with addition of remediation treatments. The lowest values were recorded with addition of calcium 10 mM. Also, All plant growth parameters, Vit C and TSS concentrations were significantly increased with decreasing salinization time (60, 40 and 20 days) after transplanting. The highest values were obtained when celery plants irrigated with saline water after 20 days from transplanting. On the other hand, N02-N and NO3-N contents were increased significantly with increasing salinization time. The lowest values were recorded when plants received saline water after 20, following 40 and 60 days from transplanting. In addition, The highest tolerance to salinity effects (the best vegetative growth parameters) were obtained from the plants which irrigated with seawater dilution at 15% after 60 days from transplanting and treated with polymer + Ca, while the less tolerant plants were the plants which irrigated with seawater dilution after 20 days from transplanting. Also, data indicated that the highest values of Vit C and TSS concentrations were obtained under high salinity level (25% seawater) with addition of polymer + Ca2 and irrigation with saline water after 20 days from transplanting. Meanwhile, NO2-N and N03-N contents were significantly decreased with increasing salinity levels, addition of remediation treatments and irrigation with saline water at early stage of plant growth (after 20 days from transplanting). Also, it reduces the free nitrate in plants of celery which is useful to the health of consumers. In general, it can be concluded that: -The highest tolerance to salinity with best quality was obtained from the plants which irrigated with seawater dilution at 15% (9 dS/m) after 60 days from transplanting and treated with polymer + Ca 10 mM under EI-Dakahlia governorate conditions. -This treatment can be save about 10-150% of total water used to irrigation celery plants at different growth stages, consequently, it is considered one of ways for facing problem of fresh water scarcity in the future.