Vegetative propagation of Prunus africana: effects of rooting medium, auxin concentrations and leaf area

The region of West and Central Africa is endowed with high-value fruit trees and medicinal plants, which are currently traded locally as well as on regional and international markets. Unfortunately, they are all exploited from the wild and there has been little or no focussed effort to domesticate and cultivate them. Prunus africana is one of these important medicinal plant under domestication. A series of nursery experiments were conducted to assess the effects of rooting medium (sawdust, sand and a 50:50 mixture of sand and sawdust), auxin concentration (0, 50, 100, 150, and 200 μg IBA), and leaf area (0, 5, 10, 20, and 25 cm²) on rooting success of juvenile cuttings of P. africana. The percentage of cuttings rooted was significantly greater (P < 0.05) in sawdust (80%), than in sand alone (72%) or in mixture with sawdust (71%). Leaf area also significantly affected the percentage of rooting. Leafless cuttings did not root and were all dead by week 6, but in leafy cuttings rooting ability increased proportionally with leaf area up to 20 cm² (79%). Larger leaf cuttings (25 cm²) rooted at the same level as those of 20 cm². The cuttings with the largest leaves also had the greatest mean number of roots per cutting (14 roots cutting⁻¹), while those with the smallest (5 cm²) leaf area produced the fewest roots (5 roots cutting⁻¹). The application of auxin (IBA) promoted rooting (P < 0.05) up to an optimum application of 100–200 μg IBA per cutting, but 300 μg was supraoptimal. It can be concluded that P. africana is amenable to vegetative propagation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Establishment of Inga edulis and Calliandra calothyrsus in improved fallow systems in southern Cameroon

The adoption of planted fallow largely depends on the cost and feasibility of using the technology; easy, inexpensive and simple fallow establishment methods are known to greatly enhance adoption. It was the objective of this study to assess the effects of weeding regime on the establishment of Calliandra calothyrsus and Inga edulis on degraded acid soils in southern Cameroon. A combination of the two fallow species and two weeding regimes, weeding or not weeding, were compared to a natural fallow. The trial was conducted in two sites of different base saturation levels with four replications. The results indicate that differences between the two species and the two weeding regimes were statistically significant (p 005) on both sites for all measured tree growth parameters, as well as the residual effects on subsequent maize grain yield. Presence of weeds reduced stem diameter and height of C. calothyrsus and I. edulis at the early stage of their establishment. Weeding doubled the leaf biomass of both species. The highest woodmass was produced by Inga in plots with weeding treatment, with 48 t/ha of dry material. Tree fallow improved the yield of succeeding crops by twofold over the natural grass fallow. Weeding treatment improved maize yield, from 1.9t/ha to 2.8 t/ha after Calliandra fallow, and from 2.22 t/ha to 3.0 t/ha after Inga fallow. The significant effects of weeding treatments implies that fallow-improving tree species should be planted in relay intercropping for trees to benefit from the weeding of crops, thus reducing the labour spent on fallow establishment. This revised version was published online in June 2006 with corrections to the Cover Date.     

Early growth of Calliandra calothyrsus (Meissner) provenances in the acid soils of southern Cameroon

Provenance evaluation of Calliandra calothyrsus was conducted at Minkoameyos in Yaounde and Nkoemvone, in Ebolowa, southern Cameroon. The aim was to assess early growth performance in provenances of the species in acid soils of the region. The soils of Minkoameyos are regarded as moderately acid (pH 1:1 soil:water 5 to 6 and Al saturation < 20%) while that of Nkoemvone is referred to as very acid (pH 1:1 soil:water < 5 and Al saturation > 40%). Germination potential of the seeds was assessed at two weeks after planting. The growth performance was evaluated at three, six, nine and twelve months for height, diameter, biomass, number of stems and phenological developments. In terms of all the parameters measured, significant (P < 0.05) difference was detected between provenances. Effect of site or the interaction of site by provenance was significant for only some parameters at certain periods. Variation in the over all growth performance between provenance was high and differences between sites was minimal. This indicates that C. calothyrsus grow well both on very acid and moderately acid soils of southern Cameroon. The large genetic variation in growth and biomass production suggest that further screening to isolate desirable traits for genetic improvement effort is essential. In short-term, the current result will allow for immediate selection of superior provenances with desirable traits for use in appropriate agroforestry systems in southern Cameroon. This revised version was published online in June 2006 with corrections to the Cover Date.     

Vegetative propagation of Calliandra calothyrsus (Meissner)

The effects of propagation medium and the type of auxin on root and shoot development of stem cuttings of Calliandra calothyrsus were investigated in two experiments. Cuttings were taken from four-week-old coppice shoots from a cleared C. calothyrsus plantation. In Experiment 1, the effects of five propagation media; fine sand (FS) (3 mm), sawdust (SD), fine gravel (FG) (6 mm) and 50:50 mixtures of FS:SD and FG:SD were compared. In Experiment 2, two commercial brands of auxin rooting powder – ‘Seradix 3’ (IBA) and ‘Bouture CF’ (NAA, IBA and MNAA) were evaluated. The experiments were done in a low-cost, non-mist propagator system in Cameroon. Propagation medium had a significant (P = 0.05) effect on mean rooting percentage (FS = 43% and FS:SD = 93%). The effect of the media on shoot growth from the cuttings (height, basal diameter and root biomass) were also significant (P = 0.05). The application of both the commercial brands of auxin significantly enhanced rooting (84% for untreated cuttings and 91% for IBA- treated cuttings). Bouture CF promoted shoot development from the cuttings, while Seradix 3 inhibited shoot development. The results indicate that in the humid lowlands of Cameroon, where seed productivity of C. calothyrsus is known to be very poor, large-scale production of young plants using these techniques is possible. This revised version was published online in June 2006 with corrections to the Cover Date. This revised version was published online in June 2006 with corrections to the Cover Date.     

埃塞俄比亚的中央高地房屋建筑木材消费和树种偏好-提高树木种植的意义

2008年间在埃塞俄比亚高原调查房屋建筑木材消费和树种偏好情况,以及森林产品建设的策略和未来利用的可能性。对36座农家住户其中包括24座铁皮屋顶的房子和28座茅草盖顶的房子为对象进行调查,研究建筑木材的种类、材积和来源。结果表明,平均一座房屋的每57m^2地面空间面积需消耗木材13．7m^3。地面空间面积和木材消耗量的变化随房屋种类而变化。平均一座铁皮屋顶的房屋的每51．9m^2地面空间面积需消耗木材16．8m^3,平均一座茅草盖顶的屋顶每286m2地面空间面积需消耗木材3．2m^3。家庭和地面空间面积的大小是影响建筑木材消耗的主要因素。平均一座住房需消耗木材种类分别为,9．3％非洲铅笔柏（Juniperus procera）、5．6％墨西哥落羽杉（Cupressus Iusitanica）、29．2％蓝桉（Eucalyptus globulus）和26％赤桉（Eucalyptus camaldulensis）。由非洲铅笔柏（Juniperus procera）,墨西哥落羽杉和蓝桉来源的木材被限制。因此,目前木材短缺大约为59．5％。建议改进树木的种植方法来提高木材量,同时可研制土壤砖当作建筑材料的替代品。     

Molecular detection of piroplasms in ixodid ticks infesting cattle and sheep in western Oromia, Ethiopia

In Ethiopia, ticks and tick-borne diseases are widely distributed and contribute to important economic losses. Several studies investigated the prevalence and species composition of ticks infesting ruminants; however, data on tick-borne pathogens are still scarce. During the study period from October 2010 to April 2011, a total of 1,246 adult ticks and 264 nymphs were collected from 267 cattle and 45 sheep in Bako District, western Oromia, Ethiopia. The study showed infestation of 228/267 (85.4 %) cattle and 35/45 (77.8 %) sheep with adult ticks. Overall, eight tick species, belonging to three genera (Amblyomma, Rhipicephalus, Hyalomma), were identified and Amblyomma cohaerens (n?=?577), Rhipicephalus evertsi evertsi (n?=?290), Rhipicephalus (Boophilus) decoloratus (n?=?287), and Amblyomma variegatum (n?=?85) were the more prevalent species. A statistically significant host preference in A. cohaerens for cattle and R. evertsi evertsi for sheep was noticed. Molecular detection of piroplasms, performed only for adult ticks of two species of the genus Rhipicephalus (R. evertsi evertsi and R. decoloratus), revealed an overall prevalence of 4 % (8/202) Theileria buffeli/sergenti/orientalis, 0.5 % (1/202) Theileria velifera, and 2 % (4/202) Theileria ovis. The study showed that tick infestation prevalence is considerably high in both cattle and sheep of the area, but with a low intensity of tick burden and a moderate circulation of mildly pathogenic piroplasm species.