Environmental and chemical control of growth and flowering of Chamelaucium uncinatum Schauer

The main factor affecting floral initiation of Geraldton Wax-Flower (Chamelaucium uncinatum) is the photoperiod, while temperature is the major factor affecting flower development. Four weeks of short days (SD) are generally required for obtaining full flowering. The number of flowers produced per plant increases with increasing the number of SD. Under mild temperatures of $\text{20}\text{14°}\text{C}$ (day/night), plants initiated flowers even in long days (LD). However, fewer flowers were produced and on higher nodes as compared to SD plants. Chlormequat promoted flowering under prevailing summer conditions of high temperatures and LD. Under prevailing autumn conditions favourable for flower initiation, LD treatment or weekly sprays with gibberellic acid (GA) reduced the number of flowers per plant. Combined treatment of LD and GA reduced both the flowering percentage and the number of flowers per plant. Discontinuing the LD or the GA treatments caused a resumption of full flower initiation.     

Application of treated wastewater for cultivation of roses (Rosa hybrida) in soil-less culture

No information is available today concerning the effect of irrigation with secondary treated sewage water on growth, production or quality of roses or other cut flowers. In the present study we investigated the effect of irrigation with treated sewage water on roses cultivated in two soil-less medium, perlite, an inert mineral medium and Choir (coconut fibers), an organic medium of high ion absorption capacity. During 12 months of exposure to the treated water, the visible appearance of the plants, their growth, the quantity and size of the flowering stems and their postharvest performance were not affected by the irrigation treatments. Contents of macroelements in the leaf tissues were unaffected by the irrigation with the secondary treated sewage water. At the same time, Cl contents increased 47% in perlite and 73% in Choir grown plants reaching levels characteristic of exposure to moderate salinity. Mn, Cu and B contents increased as well under cultivation in both perlite and Choir under irrigation with treated sewage water. On the other hand, contents of Fe, Zn, Mo and Al, were similar in all treatments. In all treatments contents of all the examined micro and macroelements were within the range accepted for proper plant function.     

Missing mass in collisional debris from galaxies

Recycled dwarf galaxies can form in the collisional debris of massive galaxies. Theoretical models predict that, contrary to classical galaxies, these recycled galaxies should be free of nonbaryonic dark matter. By analyzing the observed gas kinematics of such recycled galaxies with the help of a numerical model, we demonstrate that they do contain a massive dark component amounting to about twice the visible matter. Staying within the standard cosmological framework, this result most likely indicates the presence of large amounts of unseen, presumably cold, molecular gas. This additional mass should be present in the disks of their progenitor spiral galaxies, accounting for a substantial part of the so-called missing baryons.