In order to investigate the effects of drought stress on germination components of barley cultivars, a laboratory experiment was conducted in a factorial randomized complete design with four replications. The controlled experiment included ten of Egyptian barley cultivars namely; (Giza 123, 124, 125, 126, 127, 129, 130, 134, 135 and 2000) as first factor. The second factor included 4 levels of drought stress inducer by applying 0, 5, 10 and 20% of polyethylene glycol-6000 (PEG) which is equivalent to four osmotic potential levels including −0.001, −0.27, −0.54 and −1.09 MPa, respectively. The results showed that, the highest reduction was related to the drought level of 20% PEG among the barley cultivars. The best cultivars in terms of germination traits were Giza 134, Giza 127, and Giza 126 this indicate their tolerance to drought stress and Giza 130, 135, 2000 cultivars was moderately tolerance and remaining is less tolerance. The protein band 27 kDa and 78 kDa showed high intensity after stress in almost all cultivars. Those two protein bands their exciting was very clear in treated barley leaf tissue. It could be related to dehydrine and oxygen evolving enhancer protein 2 (OEE2) which involved in drought stress tolerance response. Cultivars Giza 127, 130 and 134 showed highest tolerance response under drought stress. The antioxidant enzymes PAGE pattern of Peroxidase (POX), Sodium dismutase (SOD) and Ascorbate peroxidase (APX) for Barley cultivars under drought stress revealed a high activities for Giza 126, 127, 134, 136 and 2000 under −0.5 MPa osmotic stress by PEG in most of their isoforms. Based on similarity coefficient values the highest values were 1.0 with 100% similarly between tolerant cultivars Giza 130 and Giza 127. Similarly between the susceptible cultivars 125 and Giza 129 was 60%.These data confirmed by the growth parameters which we ranked as tolerant to drought stress.

Background: Phosphorus is one of the essential nutrients required for plant growth. Although it is moderately available in nature, it is a deficient nutrient in most soils especially calcareous soils. Phosphate rock (PR) is considered the cheapest P fertilizer. Phosphate rock sources may be of igneous or sedimentary origin. Results: In Egypt, the natural phosphate rock is located in Sebaiya (Nile Valley), Safaga (Red Sea), and Abu Tartur (Western Desert). The higher the organic matter contents in soil, the better dissolution of the PR. Legumes are particularly suited for the use of PR. Biological solubilization of phosphate rock is more environmentally friendly than acidulation. Fungi are widely used as producers of organic acids, and particularly, some Aspergillus and Penicillium species have been directly introduced into the soil in order to solubilize the phosphate rock. Biological solubilization will make phosphorous available for plant use with minimum pollution to the environment. Phosphate rock inoculated with bacteria and Mycrrohizae proved to be a suitable approach to use PR for continuous crop production. Conclusion: The amendments such as elemental sulphur, compost, organic manure, and plant waste could be applied to PR to improve crop cultivation under Egyptian soil conditions.

No abstract

No abstract

Pots experiment were carried out in green house of National Research Centre, Dokki, Egypt, to study the effect of potassium and humic acid application to minimize the adversely effects of soil salinity on pea plants. Pots were divided into three main groups of soil salinity at levels (2.84, 6.03 and 8.97 dS m-1). These main groups were applied potassium sulfate at the rates 50 and 100 kg fed-1. Foliar application of humic acid was applied at a rate of 0.2%. Data presented that the application of K2SO4 at a rate of 100 kg fed-1 with humic acid a foliar spray at a rate of 0.2%, gave the highest values of plant growth parameters such as, Branch No., Leave No., Plant height, leaf area, Shoot fresh and dry weight. In addition to produce high chlorophyll a and b and carotene content as compared to other treatments and control under the different soil salinity levels. Application of K2SO4 (100 kg fed-1) with foliar spray of humic acid under high and moderate soil salinity condition increased pod weight, seed weight, seed dry weight over application of 50 kg   fed-1 and control. The highest values of studied chemical constituents in shoots and greens were obtained due to the application of potassium sulfate at100 kg fed-1 with humic acid. The combined effects of potassium application and foliar spray of humic acid had a positive effect on increasing the ability of pea plant tolerance to soil salinity and increasing of growth and yield production under saline soil conditions.