African Journal of Wood Science and Forestry

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 13 (1), pp. 001-009, January, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Innovative Air Layering Techniques for the Cultivation of Irvingia gabonensis

Zac Tchoundjeu, Alain Calice Tsobeng*, Ebenezer Asaah and Paul Anegbeh

World Agroforestry Centre - West and Central Africa Region (ICRAF-WCA), P. O. Box 16317, Yaounde-Cameroon.

Accepted 8 October, 2024

Irvingia gabonensis is one of the most important indigenous fruit tree species in African humid tropics. Methods have been developed for phenotypic selection and vegetative propagation of this species; but techniques for the capture of desired traits through inexpensive technological methods are still lacking. A series of experiments were conducted to assess the effects of auxin (Seradix-2) application (treated and untreated marcotts), branch diameter ( , and 4 - 5 cm), and position in the crown (lower, middle and upper) on the rooting of marcotts on one hand; and the combined effect of branch length and diameter (50 cm length, 2 - 3 cm diameter), (50 cm length, 4 - 5 cm diameter), (100 cm length, 2 - 3 cm diameter), (100 cm length, 4 - 5 cm diameter), (150 cm length, 2 - 3 cm diameter), (150 cm length, 4 - 5 cm diameter) on the survival of rooted marcotts on other hand. After 12 months, the proportion of rooted marcotts was significantly higher (P < 0.05) for untreated (50 ± 7.3%), than for treated marcotts (31 ± 6.7%). Marcotts of 3 - 5 cm diameter rooted significantly better (46.9 ± 5.1%) than those of 2 - 3 cm of diameter (32.1 ± 5.2%). Branch position in the crown did not affect rooting ability of marcotts. After 8 weeks, the highest survival rate of weaned marcotts (40%) was observed for those with 100 cm length and 2 - 3 cm diameter while the highest mortality rate was obtained for those with 150 cm length and 4 - 5 cm of diameter (90%). It can be therefore concluded from this study that I. gabonensis is amenable to air-layering but further studies are needed to improve the survival rate during the weaning period.

Key words: Irvingia gabonensis, domestication, marcotting, rooting ability, auxin, branch diameter, length and position.

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 13 (1), pp. 001-010, January, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Effects of Leaf Nitrogen and Potassium on Fruit Yield, Quality, and Biomass Production of Clementine Mandarin under Mediterranean Climate Conditions

Abdelkader Hammami*, Salah Rezgui and Rachid Hellali

National Agronomic Institute of Tunisia

Accepted 4 December, 2024

Leaf analysis is a useful tool to evaluate the nutrient status of citrus trees, but diagnosis standards for ‘Clementine mandarin’ are not available. Nutrition recommendations of the current fertilization practices are mainly based on the same recommended nutrient rates for orange trees. A three-year (2005 - 2007) field experiment was conducted in North Eastern Tunisia (El Gobba). This experiment was carried out using 25 years old ‘Clementine mandarin’ trees (CITRUS RETICULATA OSBECK) on ‘Sour orange’ (CITRUS aURANTIUM OSBECK) rootstock; grown on a sandy soil; to establish leaf nutrient (N and K) concentration standards for optimum biomass tree growth, fruit production and quality. Nitrogen and potassium rates ranging from 160 to 232 and 200 to 290 kg/ha/yr, respectively, were applied in a drip irrigation system (12 fertigations events/yr). Irrigation was scheduled based on tensiometer readings at the root zone. Fruit yield was positively associated with N (r2 = 0.91) and K (r2 = 0.84) rates; as well as with leaf N concentration (r2 = 0.92) and tree fruit load (r2 = 0.91). Leaf N concentration was significantly correlated with N rates (r2 = 0.72) and biomass tree growth (r2 = 0.52). These findings indicate that 192 and 200 kg/ha/yr of N and K2O (N:K = 0.9), respectively, are required to support optimal fruit yield of 43 T/ha/yr with tree fruit load of 2.4 kg/m3 (fruit yield/tree canopy size ratio) and optimum fruit quality. At 90% of maximum relative fruit yield, leaf N and K concentrations were 27 to 29 and 10 to 12 g/kg, respectively. Leaf nutrient concentration ranging from 27 to 29 g/kg for N; and from 10 to 12 g/kg for K corresponding to a fertilizer management program of 192 kg/ha/yr and 200 kg/ha/yr, could be recommended as optimum levels of N and K for ‘Clementine mandarin’ grown under Mediterranean conditions.

Key words: Leaf nutritional status, optimum fruit yield, biomass tree growth, Clementine mandarin, semi arid Mediterranean climate.
 

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 13 (1), pp. 001-012, January, 2025. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Ecological Comparison of Primary and Secondary Forests in Mount Oku, Cameroon

MOMO Solefack Marie Caroline1*, TEMGOUA Lucie Félicité2, NGUEGUIM Jules Romain3 and NKONGMENECK Bernard-Aloys4

1Laboratory of Applied Botany, Department of Plant Biology, Faculty of Science, University of Dschang, P. O. Box: 67
Dschang, Cameroon.
2Department of Forestry, FASA, University of Dschang, P. O. Box: 222, Dschang, Cameroon.
3Institut de la Recherche Agricole Pour le Développement (IRAD), Cameroon.
4Department of Plant Biology and Physiology, Faculty of Science, University of Yaounde I, P. O. Box 812, Cameroon.

Received 7 July, 2024; Accepted 1 September, 2024

Globally, human populations are rapidly converting large blocks of tropical old-growth forests into small forest patches, embedded within human-modified landscapes, consisting mostly of agricultural fields and pasture lands. Mount Oku commonly known as Kilum-Ijim, situated at the North-western Cameroon is recognized as a globally important center of endemism and a hotspot for biodiversity conservation but now undergoes unprecedented degradation. The aim of this study was to compare the diversity between primary and secondary forests in mount Oku (Cameroon) and determine whether species richness and composition are distinguishable in the two forest types. The vegetation was sampled in 102 plots according to a stratified sampling design so as to cover the altitudinal gradient from 1833 to 2772 m. Forty plots were located in primary forest and 62 in secondary forest. A set of 6 plant traits/characteristics associated with dispersal, establishment, and persistence functions were gathered. A total of 385 vascular plant species were present in the 102 plots. 243 species were common to primary and secondary forest plots, 69 were present exclusively in primary forest plots and 73 in secondary forest plots. The Indicator Species Analysis showed that 38 and 28 species were indicator of primary and secondary forests, respectively. The mean species richness per plot was 45.5 and 44.1 in primary and secondary forests, respectively. Only tree species richness was significantly higher (p < 0.001) in the primary forest. The maximum height of vegetation and density of trees were respectively 19.42 m, 101 stems/ha in primary forest and 11.93 m, 36 stems/ha in secondary forest and show significant difference (p<0.001). Primary forest plots were characterized by phanerophytes, while secondary forest plots were characterized by geophytes and chamaephytes, able to propagate vegetatively and resist disturbances. Finally, there is need to urgently protect the last remnants of ancient forest for their biological value.

Key words: Afromontane forest, biodiversity, endemism, human activities, mount Oku, species composition, species richness.
 

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 12 (8), pp. 001-006, August, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Association between Hymenoscyphus pseudoalbidus and Ash Dieback in Austrian Forest Nurseries

Thomas Kirisits*, Peter Kritsch, Katharina Kräutler, Michaela Matlakova and Erhard Halmschlager

Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna (BOKU), Hasenauerstraße 38, A-1190 Vienna, Austria.

Accepted 10 April, 2024

Abstract

Dieback of Fraxinus excelsior, Fraxinus angustifolia and other Fraxinus species is an emerging infectious disease caused by the ascomycete fungus Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea). Investigations in five forest nurseries in Austria from 2008 to 2011 showed that ash dieback is a common and important disease of nursery seedlings. H. pseudoalbidus was consistently isolated at high frequencies from symptomatic F. excelsior and F. angustifolia seedlings, confirming that this fungus is associated with ash dieback. Symptom observations on potted seedlings revealed progression of the disease outside the vegetation period and thus a long incubation period in the disease cycle of ash dieback. Apothecia of H. pseudoalbidus were occasionally observed on dead ligneous parts of common ash, including stems of nursery seedlings. This suggests that a low portion of diseased seedlings can initiate new infections, which may be important for moving the pathogen to new areas. Based on our observations and studies in forest nurseries and the present knowledge on the disease cycle of ash dieback, recommendations for disease management in tree nurseries and concerning artificial regeneration are presented.

Key words: Chalara fraxinea, Fraxinus excelsior, Fraxinus angustifolia, emerging forest disease, disease management.
 

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 12 (8), pp. 001-008, August, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Impact of Hymenoscyphus pseudoalbidus on Fraxinus excelsior Seed Plantations in Austria

Thomas Kirisits* and Christian Freinschlag

Institute of Forest Entomology, Forest Pathology and Forest Protection (IFFF), Department of Forest and Soil Sciences, University of Natural Resources and Life Sciences, Vienna (BOKU), Hasenauerstraße 38, A-1190 Vienna, Austria.

Accepted 30 April, 2024

Abstract

Ash dieback, an emerging fungal disease incited by Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea), causes immense damage to Fraxinus excelsior in many parts of Europe. There is hope that some individuals of this tree species display high levels of resistance to the disease. In 2009 and 2010, the intensity of ash dieback was investigated in an ash seed plantation in Upper Austria, consisting of 51 clones of local provenance. A specific rating system for visual inspections was developed to assess shoot, twig and branch dieback as well as leaf shedding. Considering all 187 evaluated trees, mean ash dieback intensity was 18.1% in July 2009 and 17.6% in July 2010. Disease intensity varied greatly between clones, ranging in both years from almost no dieback to more than 80% dieback in the most severely affected clone. Likewise, levels of leaf shedding in July and September differed considerably between clones. However, no clear relationship between leaf shedding and dieback intensity was observed. The results indicate that F. excelsior clones in the seed plantation may indeed differ substantially in their resistance to H. pseudoalbidus.

Key words: Chalara fraxinea, common ash, disease assessments, emerging fungal disease, resistance.
 

African Journal of Wood Science and Forestry ISSN 2375-0979 Vol. 12 (7), pp. 001-007, July, 2024. Available online at www.internationalscholarsjournals.org © International Scholars Journals

Full Length Research Paper

Exploring the Marketing of Non-Timber Forest Products in Nigeria: A Focus on Osun State

Aiyeloja, Adedapo Ayo¹* and Ajewole, Opeyemi Isaac²

¹Department of Forestry and Wildlife, University of Port Harcourt. Nigeria.
²Department of Forestry, Wildlife and Fisheries Management, University Of Ado Ekiti, Nigeria.

Accepted 10 April, 2024

Abstract

Research on markets and marketing of some non-timber forest products (NTFPs) was carried out in selected locations of Osun State. The NTFPs considered are chewing sticks such as Massularia acuminata and bush meat like Thryonomys swinderianus, representing both the flora and fauna aspects of NTFPs, respectively. Five Local Government Areas were randomly selected, namely; Odo-otin, Boripe, Iwo, Irewole and Atakunmosa for the research purpose. A total of 300 questionnaires were administered, 150 questionnaires for each of the NTFPs. Each NTFPs was further subdivided to production, marketing and usage or consumption with 50 questionnaires for each unit. It was gathered from the result that M. acuminata tops the list of the well favoured chewing sticks. Other types of chewing sticks that rank high include fagara ( Zanthophylum zanthoxonoides) and Ira (Rauwolfia vomitora). Bush meat is also cherished by people most especially in urban centres where it is regarded as a delicacy. Despite the preference of bush meat, the rate of consumption is still low relative to other animal protein sources. Apart from these two NTFPs, several others of economic, nutritional and medicinal importance exist. A list of some of them is made with their uses. NTFPs are grossly affected by seasonal changes and this in turns affect their availability and prices. In all, considering NTFPs in the light of economic gain alone will be parochial even though analysis for the marketing of the two NTFPs shows that they are viable business ventures. The values should extend beyond the economic gain to other values which are indispensable to the existence of man. A major but neglected aspect is the medicinal aspect of NTFPs.

Key words: Forest products, NTFP, marketing, Nigeria.