Nursery Pest Management of Phytolyma lata Walker (Scott) Attack on Iroko (Milicia excelsa Welw C. C. Berg) Seedlings

The establishment of plantations of Milicia excelsa has been constrained by the gall-forming psyllid Phytolyma lata Walker (Scott) that causes extensive damage to young plants. We present findings of an experiment aimed at preventing Phytolyma attack on Milicia seedlings in the nursery using chemical control and physical barrier (screen house). Ninety, 6-month old seedlings of uniform growth were selected from a population of potted seedlings obtained from the same seed source. Thirty seedlings were placed in a screen house (SHS), while thirty seedlings (TRT) were placed in the open nursery under direct sunlight and treated fortnightly with a low concentration (0.05%) of water-based insecticide (Lambda-Cyhalothrin). As control (UNT), 30 seedlings were placed in the open nursery without any treatment. The survival, height and collar diameter of the seedlings were measured fortnightly for 24 weeks. After 10 weeks, the untreated seedlings were attacked by Phytolyma with evidence of leaf gall formation. Though, all UNT seedlings were attacked by the insect no, mortality was recorded during the study, while no gall formation occurred in the TRT and SHS seedlings. There was no significant difference in the collar diameter growth with 90.71%, 97.73%, and 115.48% increase in UNT, TRT and SHS seedlings, respectively. On the other hand, there were significant differences in the total height with 21.98%, 58.19%, increase in TRT and SHS, respectively; while UNT seedlings experienced a negative height growth of -0.27%. The provision of a physical barrier proved to be the most effective management strategy to prevent Phytolyma infestation, while chemical control was a successful alternative.Key Words: Iroko, gall formation, screen house, Lambda-Cyhalothrin, Phytolym

Deforestation Trends in Forest Estates of Vandeikya Local Government, Benue State, Nigeria

The variation in total forest area over time (years), the number of forest offences and annual forest fires was appraised in Vandeikya Local Government (VLG) Area, Benue State, Nigeria. Six wards were randomly selected from the twelve wards making up the Local Government. These wards were: Mbadede, Mbagbera, Mbaakaange, Mbaityough, Ningev and Tsambe. All the sixteen staff members of the VLG Forestry Service were interviewed. Secondary data was also obtained from VLG Department of Agriculture on forest areas, forest offences and annual fires .The study compares data for any observed variations that may have occurred in subject parameters at five year intervals between 1955 and 2000. A total of 1642 forest offences were recorded within the period. The total forest area for the six sampled wards was 312.9ha in 1955. This area declined to 193.5ha in 1980 and to 83.5ha in 2000. There were no significant differences (P>0.05) in the number of forest offences between the years though differences between the following pairs of wards were significant (P<0.05): Mbadede and Mbakaange, Mbagbera and Mbakaange, Mbagbera and Mbaityough, Mbagbera and Ningev, Mbakaange and Ningev as well as Mbakaange and Tsambe. Forest fires recorded within the same period totalled 192. There were significant differences in the number of forest fires reported between the wards such as Mbadede and Mbagbera, as well as Mbadede and Ningev (P<0.05), however, the number of forest fires were not significantly different over the years (P>0.05). Among other measures, increased reforestation efforts involving the rural communities using both indigenous and exotic tree species is suggested. Also, there is need to sensitise members of the public on sustainable forest management and its merits

Appraisal of Taungya Farming as a Sustainable Land-Use Option in Vandeikya Local Government of Benue State, Nigeria

This study appraises taungya farming as a sustainable land -use option in Vandeikya Local Government (VLG) forest estates, Variations in the yield of agricultural crops over time (years), incidences of annual forest fires, forest offences as well as changes in forest area between 1955 and 2000 were assessed. Six out of 12 council wards in VLG were randomly selected for the survey through multi-stage random sampling. A total of 200 farmer respondents were sampled out of a taungya farmer population of 562 in the selected wards. All the 16 members of staff of the VLG forestry service were interviewed. The two categories of respondents were then interviewed using the same type of semi-structured questionnaire. This was to check and corroborate the responses of both groups of respondents. Data collected was subjected to descriptive statistics (like percentages) and inferential statistics [such as analysis of variances (ANOVA)]. The mean yields of yam, cassava, sweet potatoes, rice, maize, groundnuts, soybeans, guinea corn, beans, pepper and melon on taungya plots ranged from 306.67kg/ha for melon to 1698.33kg/ha for cassava. The corresponding yields of melon and cassava on non-taungya plots were 250.00kg/ha and 1372.67kg/ha, respectively. Crop yields were significantly higher on most taungya plots except that of melon (p>0.05).The total forest area declined from 312.9ha in1995 to 83.5ha in 2000. Reforestation with indigenous tree species, establishment of seed and clonal banks, adoption of socially and ecologically acceptable taungya practices, review of land tenure laws and sensitization of farmers on sustainable taungya practices are advocated

Agricultural productivity under taungya and non-taungya land-use options: A case study of Vandeikya Local Government area, Benue State, Nigeria

Taungya farming is a special arrangement between the forestry department and farmers, which combines the production of both arable and forest tree crops simultaneously on a piece of land. The practice was adopted in Vandeikya Local Government area of Benue State Nigeria, in mid 1950s up to 2000. This study evaluated the method as an option for food and fiber production compared to the traditional farming and forest management practices. Using Stratified random sampling, two sets of questionnaire were used to appraise the productivity of some arable crops and forest regeneration under taungya and non-taungya cultural practices. The yields of arable crops were significantly higher under taungya farming that in non-taungya plots in the study area. There was however no significant difference in the total forest area regenerated under the two landuse systems. The apparent land hunger among farmers is a favourable factor for adoption of taungya as a land use option in the study area. There is need to adopt multi-species planting approach in future programmes. Also, the land tenure system which limits access to land by strangers needs to be reviewed and greater awareness on the programme needs to be generated among the farmers and forestry staff alike.Keywords: Taungya, agroforestry, arable crop, productivity, fores

Fungicidal control of two pathogenic fungi of Parkia biglobosa (Jacq) benth

The efficacy of two fungicides, Benlate and Thiram were evaluated in vitro against Aspergillus tamarii and Corynespora cassiicolla, two fungi isolated from the seeds and leaf-spot of Parkia biglobossa. The fungicides were tested at four concentrations of 0.1, 1.0, 10 and 100 ppm impregnated into Potato Dextrose Agar (PDA). The radial growths of the fungi on PDA were compared. Analysis of variance was done on the data and the means were separated with LSD. Benlate was found to be superior to Thiram as it suppressed the growth of both fungi at 10ppm.Key words: Fungicides, pathogenicity, Parkia biglobossa, Corynespora cassiicola, Aspergillus tamari

Tree species Diversity in the Department of Forest Resources Management, University of Ibadan, Nigeria

Trees, which are important for the sustenance of life and the health of our planet, are disappearing at an alarming rate. Consequently, the need for actions to develop effective strategies to conserve them is receiving considerable attention worldwide. Forest genetic resources are fast becoming depleted in most natural forests due to the pressures of deforestation, urbanization, poor management and a regeneration programme that is virtually nonexistent. In Nigeria, the impacts of climate change will further aggravate the plight of many indigenous and exotic tree species as climatic variability may limit the ability of forest trees to quickly adapt to the changing climate. The huge presence of various indigenous and exotic tree species on the University of Ibadan campus and the fact that some of these trees are no longer found in most natural forests underscores the potentials of the campus as an important live gene bank. There is little or no information on the taxonomy, diversity and growth characteristics of many of the trees on campus. This information is very important for their conservation and sustainable management. There is therefore, an urgent need for their identification, conservation and management. An inventory of trees (>10cm diameter at breast height (dbh)) growing within the premises (~1.2ha) of the Department of Forest Resources Management (DFRM), University of Ibadan, Nigeria, was conducted as a case study of the species quality (richness and diversity) and quantity (volume) found on the University campus. The trees were identified to species level and the total height, merchantable height, canopy cover, diameters at the base, breast height and top of each tree was measured and volume calculated. The health status of trees was visually assessed based on the presence or absence of disease symptoms and pest attack. Data were analysed using descriptive statistics. A total of 27 species from 15 families were identified with Eucalyptus torrelliana F.V. Muell. and Gmelina arborea Roxb. representing 19% and 18%, respectively. A mixture of 14 indigenous and 13 exotic tree species was found within the study area including some threatened indigenous species such as Milicia excelsa (Welw) C. Berg. and Khaya grandifolia Thompson. The mean total height, merchantable height, volume and dbh were 15.57 ± 0.73m, 9.11 ± 0.57m, 6.68 ± 1.10m3 and 44.58 ± 3.58cm, respectively. Eleven percent of the trees were in a ‘very good’ state of health (i.e. no signs or symptoms of pest and disease attacks) while 4% were in a ‘bad state’ (major leaf defoliation, leaf galls, growth of epiphytes and stem rot). It was also observed that only 16% of the trees had straight boles while others had crooked and epicormic branches. The study indicated high species variability within a small area of 1.2ha. There is a need for policy intervention to aid the identification, documentation and conservation of forest genetic resources in the University. Keywords: Species diversity, University of Ibadan campus, Climatic variability, Tree healt

Control of Phytolyma lata Walker (Scott.) Attack on Milicia excelsa (Welw.) C. C. Berg seedlings under plantation conditions

In this study, five Phytolyma pest control measures which included: a mono-species plot (protected by mesh netting: T1), mixed-species plot (Milicia + Terminalia), mixed-species plot with foliar chemical treatment (T3), mono-species with foliar chemical treatment (T4) and untreated mono-species plot of Milicia excelsa seedlings (T5), were set up in a completely randomized block experiment with four replications. The total height, collar diameter and number of leaves were monitored fortnightly, while the Relative Growth Rates (RGRs) for height and diameter were estimated after 24 weeks. Data were analysed using descriptive and inferential statistics. The treatment effects significantly influenced height, collar diameter and foliage production, but the block effects were negligible. The highest mean height was in T1 (104.35 ± 2.93 cm), while the lowest was in T5 (68.15 ± 5.37 cm). The RGR for height (median = 0.013 cm-1 week -1) and diameter (median = 0.024 cm -1 week cm-1) were highest for T1, while T5 had the lowest (0.005 cm cm-1 week-1 and 0.012 cm cm-1 week-1, respectively). The provision of a physical barrier (perimeter fence) proved to be the most effective management strategy to prevent Phytolyma infestation, while the mixed-species layout was a promising alternative.Keywords: Psyllid, Mixed-species plots, Iroko, Relative growth rat

Comparative Assessment of Pathological Condition of Selected Mahogany Trees

Sustainability of mahogany trees have been threatened by the pandemic of fungal diseases, but variation exists in the level of occurrence of the diseases among the trees. Thus, diagnosing the level of susceptibility of mahogany to the diseases will be the first step to ameliorating the impact of the diseases on the trees’ abundance. This study comparatively investigated the pathological status of selected mahogany trees (Khaya senegalensis and Entandrophragma cylindricum. Diseased samples of the tree species were collected from a mahogany forest located in Ijebu-Ode, Ogun State, Nigeria. Data were collected through laboratory analysis of the samples and statistically analyzed with the use of ANOVA and t-test at α0.05. Result shows that E. cylindricum is more susceptible to fungal attack by collectotrichum (66.67%), aspergillus (22.22%) and fusarium (18.51%). While in K. senegalensis, the frequency of occurrence (FOC) of the diseases were 62.96%, 14.81% and 14.81% respectively. There was however, no significant different in the FOC of the two species. But on utility, it is better to adhere to K. senegalensis:it has less pathological weakness. Keywords: Tree collectotrichum, frequency of occurrence (FOC), mahogany fusariu