This experiment was conducted in summer seasons of 2016 and 2017 on tomato plants "6112" hybrid to evaluate tomato plants performance (vegetative growth characteristics and chemical constituents of leaves) in response to irrigation water treatments (magnetized and non-magnetized), foliar applications (chitosan, lithovit, selenium and yeast extract) and their interactions. Results indicated that the highest values of vegetative growth characteristics, i.e., plant height, number of branches, number of leaves, leaf area, fresh and dry weights as well as chemical constituents of leaves as photosynthetic pigments (Chl. a, Chl. b, total Chl. a+b and carotenoids) and leaf minerals content (N, P, K, Ca, Mg, Zn, Mn) were recorded when plants irrigated with magnetized water as compared with plants irrigated with untreated water in both studying seasons. On the other hand, Fe content responded negatively to irrigation with magnetized water.Comparing the effect of foliar applications, all foliar application treatments significantly enhanced vegetative growth parameters, leaf minerals and pigments contents compared to the check treatment. Foliar application of chitosan at 250 ppm is the superior in its effect on all the aforementioned characteristics followed by yeast extract at 10 g/L then lithovit at 1.5 g/L in the two seasons except for Fe content. The best results of both vegetative growth attributes and chemical constituents of leaves were recorded when plants irrigated with magnetized water and sprayed with chitosan at 250 ppm in both seasons. Thus, this treatment could be recommended to improve tomato plants performance under similar conditions of this study.

Two pot experiments were carried out in the farm of Fac. of Agric.; Mansoura university during the two successive summer seasons of 2008 and 2009, to investigate the effect of soil salinity levels and some antioxidants on plants growth, yield and quality parameters of Jew's mallow (Corchorus olitorius L.) cultivar "Balady". Four treatments of salinity in this study (control, 3000, 6000 and 9000 mg/l) and four antioxidants with three levels for each (ascorbic acid, salicylic acid, proline at; 100, 200 and 300 mg/l and yeast extract at; 1000, 2000 and 3000 mg/l) were used in the foliar way as well as the control treatment (tap water). The results obtained from this work could be summarized as follow: a) All vegetative growth parameters under investigation were significantly decreased as the level of soil salinity was increased. b) Foliar spraying of Jew's mallow plants with antioxidants significantly increased the mean values of the vegetative growth parameters as compared to the untreated treatment. c) The highest level was most pronounced and associated with the highest mean values for all previously mentioned traits comparing with the first and second level of foliar amendments. d) Foliar spraying of proline combined with the levels of soil salinity was superior for increasing the values of these parameters following by yeast extracts, ascorbic acid and finally salicylic acid treatment. e) There was a significant decrease as the level of salinity was increased on No2-N and No3-N contents, while ascorbic acid was increased. f) Both No2-N and No3-N were decreased significantly with antioxidant treatments.

The present study was carried out at a private farm located in Bohout Village, Nabaroh District, Dakahlia Governorate, Egypt to assess the influence of different amounts of applied irrigation water, different types of antitranspirants and their interactions on vegetative growth parameters (i.e, plant fresh and dry weights, plant length, number of leaves and Leaf area), leaf chemical constitutes (i.e, N, P, K percentage as well as total Chlorophyll (a+b) content and leaves proline content) and seed yield and quality (i.e, seed yield plant-1 , plot-1 , feddan-1 , weight of 100 seeds and seed germination percentage) of squash plants (Cucurbita pepo L.) during the two successive summer seasons of 2012 and 2013 under drip irrigation system. The experiment included fifteen treatments resulted from the combination of three irrigation water levels (100%, 80%, 60% from ETc) and five antitranspirants (kaolin, CaCO 3 , MgCO 3 , green miracle and tap water (control)). The obtained results showed that irrigation with 100% from ETc was the best irrigation treatment and the negative impact of drought appeared on studied characteristics with decreasing water supply to become more serious under irrigation with 60% from ETc. The frequent foliar application of antitranspirants played a remarkable role in alleviating the hazard of drought stress. However, all antitranspirants had promotive effects, kaolin foliar application gave the best results on all studied characteristics. It improved vegetative growth, leaf chemical constitutes and increased seed yield and quality parameters under both non-stress and stress conditions. Moreover, Kaolin treated plants irrigated with 80% from ETc performed better even than untreated plants irrigated with 100% from ETc. According to findings of the current study, summer squash can be protected from the negative consequence of the drought by frequent foliar applications of reflective antitranspirants such as kaolin, as it proved to recover the growth as well as seed yield quality under water limitation conditions.

Two separate experiments were carried out in a private farm in El-Matria; Dakahlia Governorate, Egypt during two successive seasons 2009/2010 and 2010/2011 to study the effect of potassium sources (potassium mono phosphate 52% K2O potassium sulphate 50% K2O and potassium citrate 38% k), levels (0, 60 and 120 kg K2O/ fed for each source), phosphorus sources (calcium super phosphate 15.5 % P2O5, rock phosphate 30 % P2O5 and phosphoric acid 85% P2O5) and levels (0, 30 and 60 kg P2O5/fed for each source) on vegetative growth, tuber yield and chemical constituents of potato (Solanum tuberosum L.) "Spunta". Treatments were arranged in randomized complete block design in three replicates. The obtained results indicated that both potassium mono phosphate at 120 kg K2O/fed and phosphoric acid at 60 kg P2O5/fed gave the highest values of vegetative growth parameters, tuber yield and its quality in both seasons as compared with other treatments and the differences were significant.