The effect of some experimental treatments on the germination of Cupressus arizonica seeds. Cupressus arizonica L.

This research aims study the effect of different treatments in activate and increase percentage of germination Cupressus arizonicaL.seeds to use plants in forestation projects, seeds were get from mature conifers, and tested by different treatments with control, then cultured within polyethylene bags many times to calculate indicators of germination. The results showed that the soaking the seeds Cupressus arizonicaL. in citric acid 0.1% with cold wet stratification for 30 days at 4-5c gave higher germination percentage 75%.The treatments of the soaking seeds in sulfuric acid0.1% and hydroxide sodium 0.1% with cold wet stratification for 30 days gave respectively 60%-53% .But superiority was not significant. Other treatments; soaking the seeds in tap water 24h with cold wet stratification for 30 days gave only 36%.But the control treatment gave lower germination percentage of all just only 9%. The treatment of soaking seeds in citric acid 0.1% with cold wet stratification for 30 days surpassed the rest of the treatments in effect on plant height at the end of the experiment.

Response of Lupinus albus sp. to Phosphate Rock application and the role of organic acid in its dissolution processes

The objectives of this were to investigate the response of Lupinus albus sp. to phosphate rock (PR) as a source of phosphorus (P) nutrition, and to study the role organic acid (Citric and Malic) in phosphorus dissolution from PR. Tow experiments were conducted: 1) A greenhouse pot experiment, in order to study the response of white lupin to the application of PR and Triple super phosphate TSP at three application rates (100- 450-800 ppm). 2)- A laboratory experiment in order to study the role of Citric and Malic acids concentration and initial pH in P- release from PR. The results showed that Lupinus albus sp. was able to use PR for P-nutrition, and has a relative agronomic effectiveness of 61% when compared to TSP. The possible Exuded organic acids such as Citric and Malic were responsible for PR dissolution due to tow mechanisms: 64% of PR dissolution was due to pH decrease in the rhizosphere area, and 34% due to chelating of calcium cations. PR dissolution was increased by the increase organic acid concentration, but decreased when the initial pH value increased. Dissolution was always more pronounced with citric than malic acid.