The effects of physical seed coat scarification and soaking in hydrogen peroxide (H2O2) were studied to determine presowing treatments that would improve germination in seed of Vangueria infausta. The study involved two experiments, the first conducted in the laboratory, and the second in the nursery. The scarification treatments were: unscarified control; partial removal of the seed coat at the radical end; and total removal of the seed coat. The other treatments involved soaking the seeds in 5 concentrations of H2O2, i.e., 0, 2, 4, 6 and 8%, for 12 h.Generally, less than 70% of the seeds germinated. The best germination results, (71% in the laboratory and 63% in the nursery) were obtained in seeds with partial removal of the seed coat when soaked in 6% H2O2 for 12 h. Germination in other treatments involving partial removal of the seed coat was higher than that of unscarified seed in the nursery, although laboratory values were nearly the same. Seeds whose seed coat was completely removed germinated poorly (5–16%), as a result of rapid water uptake which caused damage to internal seed structures.Hydrogen peroxide application at concentrations of 2–6% positively improved germination, while 8% H2O2 seemed to have a depressive effect. The impact of scarification and H2O2 on other germination parameters is discussed.
Tag: hydrogen peroxide
Solvothermal synthesis of CdS–graphene composites by varying the Cd/S ratio
Graphite oxide was prepared by Hummers method and treated by ultrasonic waves to obtain graphene oxide. CdS–graphene composites were successfully synthesized via a one-step solvothermal method with different Cd/S ratios, with cadmium acetate as cadmium source, thiourea as sulfur source and ethylene glycol as reaction solvent and characterized by X-ray diffraction, scanning electron microscopy and UV–vis absorption spectra. The photoelectric characteristics of CdS–graphene composites were evaluated by transient photocurrent response and three-electrode cyclic voltammetry.