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Two field experiments were performed during summer seasons of years 2005 and 2006 at El-Nuparia district, the desert backyard of El-Behera Governorate, to investigate the response of maize plant (Zea mays L.) hybrid of 30B9 to different growth regulators; Abscisic acid (ABA) at 30 and 50 ppm, Ethephon at 300 and 500 ppm and Cycocel (CCC) at 400 and 600 ppm, under different water stress treatments, which included missing only one irrigation in each water stress treatment after (Elmohayah irrigation) 10 days after germination i.e., the 2 end irrigation, the 3 rd irrigation or the 4 th irrigation beside the normal irrigation as a control treatment.Results indicated maize plants can tolerate water stress at the vegetative growth period (60 days). Missing the fourth followed by the third irrigation treatment seemed to produce more aggressive water stress for maize plants rather than those produced when missing the second and normal irrigation, respectively.Spraying growth regulators i.e. (ABA, Ethephon or CCC) on maize plants reduced significantly plant height, fresh weight and leaf area as compared to the control treatment. Vice versa, it increased significantly plant dry weight, number of leaves, total pigments, chlorophyll, free proline, endogenous abscisic acid, osmotic pressure, ear weight, number of grains, 100 grain weight, and both biological and grain yields as compared with the control treatment. Superior results were obtained by applying the higher concentrations of ABA and CCC, and lower concentration of Ethephon compared with the other treatments.Under normal irrigation conditions, it is not recommended to spray any of the studied growth regulators on maize plants for its negative effects on plant growth, productivity and chemical composition. While, under water stress conditions, applying growth regulators increased the plant tolerance to water stress which led to produce appreciated yields under these conditions after improving the physiological adaptation to water stress, yet, growth characters was declined. Higher observations under severe water stress conditions were obtained from applying abscisic acid, ethephon then cycocel at the higher concentrations, respectively.

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Phytoextraction of heavy metal from contaminated soils is promising remediation technology. In the present study, hyper-accumulator plants, indian mustard (Brassica juncea.(L) czern) and ryegrass (Lolium multiflorum Lam) have been used to remove the excess undesirable concentrations of zinc and copper from contaminated soil. Zinc and copper uptake have been enhanced by adding EDTA to the contaminated soil using two concentrations (2.5 and 7.5 mmol/Kg soil). Accumulation of Zn by the indian mustard shoots and roots under the effect of EDTA recorded 4 to 6 times as adsorbed by the control while less enhancement of Zn uptake was recorded by the ryegrass shoots and roots. On the other hand, Cu accumulation showed significant enhancing by the ryegrass shoot comparing to the indian mustard shoot at the both employed EDTA concentrations. The ryegrass roots gave enhanced Cu uptake at the EDTA conc. 7.5 mmol/Kg soil only while the indian mustard roots recorded an increasing in the Cu-uptake with the two EDTA concentrations

In order to study the effect of some growth regulators treatments on callus growth as affected with the interaction between three different temperatures (18, 23, 28 o C + 2 o C), photoperiod, type of explants and incubation period. Three experiments were carried out during the two successive years 2001 and 2002. The results indicated that, the interaction between the different treatments led to significant difference in callus growth when incubation at different temperature degrees (18, 23 and 28 o C). The suitable temperature degree for growth of echinacea explants was 23 o C. Culturing the explant under the light condition encouraged the callus growth in light than dark.The explants under investigation recorded significant difference in callus growth and the cotyledonary leaf explant was the best one. The first treatment activated the callus growth significantly than the second and third treatments. In addition, significant increment was achieved in callus growth with increasing incubation period, and the best incubation period for callus growth was 35 day.The interaction between different treatments showed that the callus growth was increasing significantly with increasing the incubation period even with different growth regulators treatments, explant type, photoperiod, and different temperature degrees (18, 23, and 28 o C).As for the interaction between factors controlling callus establishment, it is clear that the most convenient conditions on the optimum growth of echinacea callus tissues are application of cotyledonary leaf explant, MS basal medium supplemented with BA 1.5 mg/L + NAA 1 mg/L & BA 2 mg/L + NAA 1 mg/L and light condition for 16 hr./day photoperiod at intensity of 6000 Lux, at 23 o C for 35 day incubation period.