Grapes are one of the most important fruit crops in Egypt
Grapes are one of the most important fruit crops in Egypt, due to the encouraging economic return both in domestic marketing and exporting. So, grapes areas were increased rapidly especially in new reclaimed lands. The major problem of the newly reclaimed lands in Egypt is soil salinity, which occurred as a result of scarcity of water sources as known in arid and semi-arid regions for irrigation and leaching the excess salts from the plant root zone; also it could be occur when poor quality water is used for irrigation. Salinity decreases grapevine growth and yield, due to osmotic stress, imbalance of nutrients uptake and ion toxicity (Mittler, 2002 and Ennab, 2016). The extension of grapes cultivation under the above mentioned conditions is an incentive to carry out further researches for finding out some appropriate agricultural practices that promote growth and improving production under salt stress. In this respect, magnetic iron and antioxidants like Ascorbic acid and Salicylic acid can play an important role under these conditions.
Magnetized water is technique which has become attention of researchers as physical way, since it maintains a purity of the environment, easy to use and health safety. This technique makes some changes of water molecules when it passes through a magnetic field either through a magnetic tube or through magnetized iron particles as water electrical properties, elasticity, water surface tension, enhancing the capacity to dissolve salts, increasing the amount of oxygen dissolved in water, enhancing permeability and accelerate the soil chemical reactions (Dandan and Shi, 2013). These changes are enhancing water molecules energy and flowing. So, it affects on soil physical, chemical and biochemical properties (Al-Jubouri and Hamza, 2006). Magnetized water prevents damaging some metals as, nickel and lead from uptake by plant roots (Taia et al., 2007). Moreover, soil application of magnetic iron increased soil macro and micronutrients this reflected to increasing tree height, fresh and dry weight of pear leaves (Osman et al., 2014). Magnetic iron was very effective in stimulating vegetative growth parameters of “Thompson seedless” as main shoot length, wood ripening and total leaf area/vine, also enhanced leaf nutrients N, P, K, Mg, Ca and Fe percentages and increased Yield and different berries quality parameters however, it reduced leaves chloride, proline and sodium contents (Ali et al., 2013).
Antioxidants play an important role in improves salinity stress resistance in several plant species (Khan et al., 2012). Ascorbic acid (AsA) is an important plant antioxidant; it is synthesized in higher plants mainly throughout conversion of d-glucose to Ascorbic acid (Foyer and Noctor, 2005). It has an essential job in numerous physiological processes of plants as differentiation, growth, and metabolism. Moreover, AsA has fixed free radicals which produced as a result of plant metabolism, thus enhancing plant resistance mitigate stresses (Shalata and Neumann, 2001). Exogenously applied of AsA was generally effective mitigate the negative effects of salt stress on leaf photosynthetic rate and membrane integrity through stimulate action on these parameters, it was more clear in plants under moderate and low salinity stress (Hamada and Al-Hakimi, 2009). So, it can be used like growth regulator for improving the resistance of numerous plant species to salinity stress (Khan, 2012), enhancing growth and cluster quality of “Thompson seedless” grape (Wassel et al., 2007) and “Flame seedless” grapevine (Elsayed et al., 2000).
Salicylic acid (SA) can be considered as an endogenous plant hormone where, it has cleared an intermediate with the biosynthesis action of cytokinins and IBA. So it plays an essential role in plant growth. (Josephe et al., 2010). SA is classified as a growth promoter, since it enhancing plant growth, development and plant vigor under abiotic (drought, salinity and deficit irrigation) stresses (Hayat et al., 2010). External application of Salicylic acid with different methods (seeds soaking, in the hydroponic solution, with irrigation, or foliar sprays) resulted in enhancing various plant species protect against abiotic stress through inducing tolerance mechanisms processes (Horvath et al., 2007), enhancing, yield and berries quality of some grapevine cvs. (El-Kady, 2011; El-Hanafy, 2011 and Ahmed et al., 2014). SA prevents fruit softening by affecting activities of major cell wall degrading enzyme such as cellulase, polygalactouronase and xylanase (Wang et al., 2015). Foliar application of salicylic acid at (100 and 150) mg/l improved cluster weight, berries weight, juice volume, total chlorophyll content, N.P.K of leaves, T.S.S, acidity and total phenols of (Bez El-Naka) grapevine cultivar (Abdel-Salam, 2016).
Therefore, the purpose of this study is evaluating the potential effects of magnetic iron and some antioxidants to mitigate the stress occur on vines growth, yield and fruit quality of “Flame seedless” grapevine grown in salt affected soil.