To investigate the effect of nitrogen fertilization forms (ammonium sulphate and calcium nitrate) and some bio-stimulants (humic acid, fulvic acid, EM and yeast extract) under high temperature on flowering characters, yield and its components of cucumber (Cucumis sativus L.) cv. Prince, two field experiments were carried out in a private farm at El-Mahalla El-Kubra-Gharbia governorate during the two successive summer seasons of 2011 and 2012 Results showed that the (50%NH4 + 50%NO3) treatment of N-forms increase No. of female flowers, fruit setting, early and total yield significantly, while No. of male flowers and sex ratio decreased significantly. Foliar spraying of cucumber plants with bio-stimulants significantly increased the mean values of the No. of female flowers, fruit setting early and total yield as compared with the control treatment. The best foliar application were yeast extract at 10 g/l or effective Microorganisms (EM) at 20 ml/l. Therefore we recommend using nitrogen fertilization as (50% NH4 +50% NO3) combined with spraying yeast extract at 10 g/l or effective Microorganisms (EM) at 20 ml/l under high temperature conditions.

Two pots experiments were conducted in Baramoon Res. Station, Dakahlia Governorate, Egypt during of 2014/2015 and 2015/2016 seasons to study the effect of some exogenous plant extracts and different calcium sources on growth , productivity and fruit quality of strawberry. Three available plants extract namely, green tea, thyme and mushroom at 2 ml /l of each as well as chitosan at 1% and different calcium sources, i.e., calcium chloride (1 %), calcium citrate (2.5 ml/l) and calcium nitrate ( 0.5 ml /l) were evaluated plus control treatment ( spraying with tap water) . The obtained results could be summarized as follows:All treatments of plant extracts, chitosan and different calcium sources had significantly increased vegetative growth, yield and its components and fruits quality of strawberry than control treatment ( sprayed with tap water) in both seasons. Spraying strawberry plants with green tea extract at 2 ml / l gave the maximum values of all vegetative growth parameters, such as plant height, fresh weight/ plant, number of leaves per plant and leaf area, concentrations of chlorophyll a and total chlorophyll in leaf tissues, both number of runners, flowers and crown / plant, crown diameter/plant and total yield/ plant as well as average fruit weight, also the highest fruit quality , i.e., pectin, Vit. C , TSS, total sugars, reducing and nun reducing and lowest values of total acidity, followed by spraying with mushroom extract at 2 ml / l or calcium nitrate at 0.5 ml/l .The increases in total yield/ plant were about 78.94 and 68.48 % for spraying plants with green tea extract and 55.93 and 62.56 % for spraying plants with calcium nitrate over unsprayed plants (control treatment ) in the 1 st and 2 nd seasons, respectively. 654 HAMAIL et al.Conclusively, from the foregoing results of this study, it could be concluded that, under the same conditions , spraying strawberry plants with plants extracts such as green tea or mushroom extracts at 2 ml / l or calcium nitrate at 0.5 ml/l were the best treatments for increasing growth , yield and gave the best fruits quality .

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.

Two field experiments were carried out in a private farm at El-Mahalla El-Kubra, Gharbia governorate during the two successive summer seasons of 2011 and 2012. The aim was to investigate the effect of nitrogen fertilization forms i.e ammonium sulphate and calcium nitrate and some bio-stimulants i.e humic acid, fulvic acid, EM and yeast extract under high temperature on vegetative growth parameters and chemical constituents in leaves of cucumber (Cucumis sativus L.) cv. Prince. The obtained results showed that the effect of N-forms was significant on all vegetative growth parameters and chemical constituents of cucumber plants. The maximum values of these parameters were executed for the treatment of (50%NH4 + 50%NO3). As for foliar spraying of cucumber, plants with bio-stimulants significantly increased the mean values of the vegetative growth parameters and chemical constituents as compared to the control treatment. The best foliar application were yeast extract at 10 g/l or effective Microorganisms (EM) at 20 ml/l. Therefore, using nitrogen fertilization as (50% NH4 +50% NO3) combined with spraying yeast extract at 10 g/l or effective Microorganisms (EM) at 20 ml/l could be recommended in case of high temperature conditions. Keywords: Cucumber (Cucumis sativus)vegetative growth parameterschemical constituents of leaves-N-forms NH4:NO3bio-stimulantshumic acidfulvic acid-effective Microorganisms (EM)yeast extracthigh temperature.

Six tomato cultivars were used. These cultivars were: (1) Castel Rock (U.S.A) (2) Edkawy (Egypt) (3) Super Marmand (France) (4) Flora-data (U.S.A) (5) B5357 (U.S.A) (6) Fline (France) crossed by using half diallel crosses mating design to obtain 15 crosses. All parent and crosses were evaluated through two seasons 2009and 2010 to evaluate heterosis for some characteristic of tomato. The results showed that, 6F1 hybrids for 15 ones gave no significant with positive values heterosis over the mid-parent for average of fruit weight in the first year. However, 3F1 hybrids for 15 ones gave significant or highly significant with positive values heterosis over the mid-parents in the second year the largest value as a result of hybrid between 3x5 with value (42.3). While the result showed that significant or highly significant with positive values heterosis over the mid-parent for fruit firmness, the largest value (24.1). The combined data over the two years showed that highly significant with positive values heterosis over the mid-parent for average of fruit weight trait ranged from (1.72% to 18.16%) came as a result between (2X3 and 3X5), fruit firmness trait ranged from (3.54% to 19.00%) came as a result between (1X4 and 2X3) respectively, total soluble solids trait ranged from (0.41% to 8.90%) came as a result between (1X4 and 4X6). while heterosis value over the better parents for average of fruit weight ranged from (0.76 to 4.06%) for the crosses (4x6 and 1x4) respectively. Also, fruit firmness ranged from (1.88% to 16.35%) for the crosses (2x4 and 2x3).