Germination of Dracaena cinnabari Balf.f. Seeds under Controlled Temperature Conditions

Effect of Different Presowing Treatments to Break Seed Dormancy and Seed Collection Methods on the Germination of Dracaena steudneri Schweinf. Ex Engl

Research Highlights: This study is focused on the germination of Dracaena steudneri Schweinf. Ex Engl. seeds using different presowing treatments. Background and Objectives: The study aimed to overcome the problem of breaking seed dormancy, to facilitate artificial regeneration for conservation and development purposes. The objectives of this study were (1) to evaluate the effect of different seed treatments in breaking seed dormancy of D. steudneri and (2) to assess the effect of the seed collection method (seeds collected on the ground vs. from the tree) on the germination of the seed. Materials and Methods: experimental study with different seed-dormancy-breaking treatments was carried out in a greenhouse and seed laboratory. T testing and one way analysis of variance (ANOVA) were used to analyse the data. Results: The applied seed treatments (hot water, cold water, sodium hypochlorite and nicking) did not improve the germination of the species, nor the breaking of seed dormancy. One-way ANOVA results also showed no significant differences between the different seed treatments and the control on the mean germination of the species in the greenhouse (p < 0.05). The t test result also revealed no significant differences in the mean germination between fallen seeds collected from the ground and in the tree crown (p < 0.05). The tetrazolium test results showed that the percentage of nonviable seeds was greater than that of the viable seeds. Conclusion: The different treatments for breaking seed dormancy did not improve the germination of seeds in the greenhouse (ranging from 0%–7%) nor in the seed laboratory (0%), which might be due to the intermediate characteristics of the seeds of this species. Therefore, we recommend that more research is undertaken on the seed ecophysiology of the species, in order to understand the mechanisms controlling its seed germination.

Multifractal analysis of air and soil temperatures

Air and soil temperatures are important agrometeorological variables with several applications. Understanding the complex behavior of air and soil temperatures, as well as their interaction, will help in agricultural planning. Multifractal detrended fluctuation and multifractal cross-correlation analysis of air and soil temperatures were carried out in three locations (Akure, Abuja, and Bauchi) within a tropical country, Nigeria. Monthly and annual air and soil temperatures measured at 5 min intervals for a period of 1 year were obtained and analyzed for multifractality. There is evidence of seasonal dependence in the multifractal behavior of monthly soil temperature. Monthly temperatures (air and soil) were found to have higher degrees of multifractality than annual temperatures. Furthermore, latitudinal dependence was observed in the multifractal behavior of air and soil temperatures. The cross-correlation between air and soil temperatures also shows multifractality with persistence at the monthly scale and anti-persistence at the annual scale. This work has shed light on the complex relationship between air and soil temperatures, and the results will be useful in modeling the two variables.