Prerequisites for biocrops Up-Scaling II: An assessment of the vegetative method of propagation for oilferous plant species with potential for biodiesel production

The rooting ability of hardwood cuttings from six selected non- edible oilferous plant species with potential for biodiesel production namely Telfairia pedata, Jatropha curcas, Excoecaria bussei, Croton macrostachyus, Croton megalocarpus and Ricinus communis was assessed on 4 differentpotting media i.e. forest top soil, sandy, clay and loamy soil. The proportion of cuttings that rooted were evaluated for the root numbers, root length, root dry weight, sprouting and callus formation. Complete  randomized design (CRD) was adopted for the experiments and each of the species was replicated 4 times using 5 hardwood cuttings per plot (5 L capacity pots). An ANOVA was computed to test for the significance of variations between all treatments while Tukey-Kramer Multiple  Comparisons test was used to test for the differences between treatment means. Jatropha curcas rooted well both in a non-mist propagator and open nursery pots, Telfairia pedata rooted only in the nursery pots, Excoecaria bussei sprouted in both non-mist propagator and open nursery pots but did not root throughout the entire experimental period of 3  months. Croton macrostachyus, Croton megalocarpus and Ricinus communis neither sprouted nor rooted calling for propagation methods other than using hardwood cuttings. Possibly all Excoecaria bussei cuttings which callused would have eventually differentiated into roots had the experiment been allowed to run for more than 3 months.Key Words: Propagation, rootability, non-mist propagators, Excoecaria bussei, Telfairia pedat

Distribution and abundance of the edible orchids of the southern highlands of Tanzania

All orchids have showy flowers and many are therefore popular as exotic houseplants as well as contributing significantly to eco-tourism. A special attribute of some orchid genera is the production of edible tubers, an attribute that can contradict eco-tourism if harvesting is not done sustainably. Such is the case in the Southern Highlands where for example, Kitulo Plateau has been gazetted to be a National Park but where edible orchid harvesting is a serious conservation problem. Botanically, unsustainable harvesting can mean the loss of important germplasm even before some species are known to exist. A field survey was undertaken for three weeks in March 2002 in the Southern Regions of Tanzania (Iringa, Mbeya, Rukwa and Ruvuma) to study aspects of the extent of the distribution, diversity and density of edible orchids. Tools for identification included structured questionnaire, on-the-spot identification as well as using herbarium voucher samples and keys. Analytical tools included Shannons' diversity index and Canonical Community Ordination (CANOCO) and ANOVA in Microsoft Excel. A total of 13 edible species of orchids were documented during the survey all of them from the genera Habenaria, Disa and Satyrium. While Tandala and Molo hills had the highest species Diversity Index (over 1.2), Kitulo Plateau showed the greatest species density of over 200/30m2 quadrants. Local communities in Madaba in Ruvuma, Molo, and Mbisi in Rukwa regions used the orchids as vegetables and snacks in lieu of animal meat. The rest of the studied areas used orchids as a source of cash by selling to Zambian traders and or to their middlemen. More research is needed to monitor growth phases, reproductive/propagation studies as well as taxonomic and systematic studies preferably using molecular techniques to determine relationships amongst edible orchids and their non edible relatives. Tanzania Journal of Science Vol. 31 (1) 2005: pp. 45-5

The Effect of Moisture and Seed Treatment on the In-Situ and Ex-Situ Regeneration of Dalbergia Melanoxylon (African Blackwood) in Pugu Forest Reserve

A study was conducted to investigate the effect of moisture and seedtreatment on the in-situ and ex-situ regeneration of Dalbergia melanoxylon in Pugu forest reserve. Seed germination experiments was conducted for three months between November and December 2005 in the nursery Botany Department of the University of Dare s Salaam while seedling growth rate measurements were conducted for 12 months between January and December 2006 in the Pugu forest reserve. A total of 2 kg of D. melanoxy seeds collected from Pugu forest reserve and some from  Tanzania Tree Seed Agency (TTSA) were used for seed germination experiments. A total of 25 seedlings approximately 2 years old were randomly chosen from Pugu forest reserve for seedling growth rate experiments. A split plot experimental design was used for seed  germination in the nursery where soaked and non-soaked seeds stood for main plot and different moisture level treatments stood for subplot. Parameters recorded were germination dates, germination percentages, seedling increase in height and seedling increase in girth. Manual computation of data was accomplished according to Zar, 1988 where LSD was used for mean separation to determine statistical differences between treatment means. Tables and Figures were used to facilitate presentation and discussion of results. Data analysis led to the conclusion that, a moderate ex-situ moisture level of 200ml in a 1L pot per day effectively promoted seed germination up to 21% in seeds previously soaked in water for 6 hours compared to high moisture treatment of 300ml in a 1L pot per day which effected seed germination only by 11.6%.. The maximum in-situ growth rate was concluded to be 0.01 cm/month. The study revealed that seeds and young seedlings of D. melanoxylon are vulnerable to highmoisture level while older trees are water and light demanding. It wasrecommended that future researches should endeavour to increase seed viability by harvesting them immediately from their maturity and storage in sealed containers, conducting tissue culture to manipulate seedlings and hybridization experiments with related species to reduce growth period.Key words: Regeneration, ebony tree, music plant, Mping

Improving propagation success of D. Melanoxylon (African blackwood) in Tanzania (II): Rooting ability of stem and root cuttings of Dalbergia melanoxylon (African blackwood) in response to rooting media sterilization in Tanzania

Dalbergia melanoxylon is a plant with valuable wood in the world and therefore is over harvested for timber while its regeneration is very low. The propagation efforts by techniques such as tissue culture or mycorrhiza have not been investigated which instigated conduction of this study. Soil and cuttings were collected from Kilwa, Kilosa and Babati for rooting test, potting media and soil characterization. The results showed that fresh soil improved rooting characteristics while sterilized soil did not due to the presence of mycorrhiza in fresh soil compared to none in sterilized media. The overall rooting in fresh soil in non-mist propagator was higher, 100% for softwood and 37% for root cuttings while none rooted in the open nursery. The results revealed that there was no significant correlation between rooting and collection sites while cutting type and the soil type used significantly influenced rooting. Softwood cuttings that weighed less than 15g significantly increased rooting at (P < 0.05) compared to cuttings that weighed above 15g. It was recommended to propagate Dalbergia melanoxylon using softwood cuttings placed in a non-mist propagator and using fresh soil infected with mycorrhiza.Key words: Dalbergia melanoxylon, non-mist propagator, rooting