Systematic wood anatomical study in some species of Sapindaceae Juss. in South-Western Nigeria

Comparative wood anatomical studies was carried out on ten species in the family Sapindaceae. The species were relatively uniform in the features of their vessels, in which diffuse porous was observed with solitary vessels to pore multiples in transverse section and ray cells were predominantly heterogeneous in radial section. Fibres were long and extensive. The longest fibre was observed in Blighia sapida (1025±28.5 µm), while the shortest fibre was observed in Cardiospermum halicacabum (139±6.5 µm). The longest vessel was observed in Deinbolia pinnata (509±34.9 µm) and the shortest vessel was observed in Cardiospermum halicacabum (85.36±4.9 µm). The implication of these features in the taxonomy of the family was discussed. The Dendrogram based on the quantitative wood characters confirmed Allophylus africanus and Allophylus spicatus belong to the same genus as classified, likewise Blighia unijugata, Blighia sapida but Cardiospermum halicacabum is closely related to Paullinia pinnata while others exhibited distinct generic characters.

Nectar secretion of Callistemon citrinus (Curtis) Skeels, Myrtaceae: Potential for honey production

The honey production capacity of bee flora is used to estimate the optimum colony carrying capacity of given area that helps to harvest the best honey yield. The research was conducted to quantify the nectar secretion pattern, the effect of temperature and humidity on dynamics of nectar secretion, and honey production capacity of Callistemon citrinus. One day before nectar collection, five inflorescences were enclosed with mesh bags on different branches of the tree. From these, twenty flowers were randomly selected per tree for the measurement of nectar volume. Additionally, nectar volume and concentration, temperature, and air humidity were measured with an interval of one hour. One way ANOVA and linear regression were used for data analysis. The average amount of nectar and its concentration were different significantly within the time of the day. Nectar amount was correlated positively with humidity while concentration was negatively correlated with temperature. The average nectar volume (µl) per flower in 24 hours, sugar amount per tree (kg), honey yield per individual tree (kg) and honey production capacity of Callistemon citrinus per hectare were 10.9+0.4, 0.65, 0.79, and 1264 kg (46-3808 kg), respectively. The real expected honey yield was 632 kg ha-1. Total financial return was estimated to be $4424 based on a value of $7 kg-1 of Callistemon citrinus honey. Therefore, the multiplication and plantation of this plant are suggested for honey production.

Soil carbon stocks of inceptisols under different land use in the Northern tropical humid region of Honduras

Soil organic carbon (SOC) is important in the carbon cycle and studies in the field are gaining relevance because of its relation to global climate change. In this paper, we report a study of SOC stock (0-200 cm) from a 50 years old secondary forest and a pasture under inceptisols in a floodplain in the tropical humid Caribbean coast of Honduras. Samples were collected at the depths 0-20, 20-40, 40-80, 80-120, 120-160, and 160-200 cm. Total SOC stocks were 89.2±10.9 Mg ha−1, and 72.5±10.0 Mg ha−1 for the secondary forest and pasture respectively. The estimated annual increase of SOC stock in the forest is 0.34 Mg C ha-1 year-1. SOC stock values were 50.3% and 47.9% of the total (0-200 cm) in the 0-20 cm layer for forest and pasture respectively. SOC distribution at a depth of 0-20 cm were 21.26 g kg-1 and 12.09 g kg-1 for forest and pasture respectively. Soil texture at the 0-20 cm depth were clay loam, and sandy clay loam, in the forest and pasture respectively. SOC stock in these ecosystems would be reduced if they were converted back to conventional agriculture, particularly in the forest. The forest had higher SOC values because of higher litter input as compared to the pasture, particularly in the upper soil layers, at deeper layers there are no significant differences (p <0.05) and SOC values are low. Compared to most other studies in tropical regions, SOC stock in our study were lower in both ecosystems, this may be due to high precipitation (ca. 3200 mm year-1) and high temperatures, rate of decomposition of litter input, general low clay content, and possibly priming effects which we have not addressed. More studies on the SOC stock in Central America with a similar climate are needed to improve our understanding of SOC dynamics and help reducing uncertainty in SOC models.

Taxonomic studies of two trifoliate legumes of high economic importance in Ebonyi State, South-eastern Nigeria

Taxonomic studies of Sphenostylis stenocarpa and Centrosema pubescens based macro-morphology and foliar epidermises were carried out to determine their similarities and differences. The taxa are of high economic values as they are used as food and medicine in Nigeria. Standard methods were used to carry out the studies as qualitative and quantitative macromorphological characters of the taxa were obtained by visual observation and measuring with metre rule while foliar epidermal study followed standard methods previously used by other researchers. The taxa studied have trifoliate leaf type with leaf and leaflet arrangement alternate and opposite respectively. From the foliar epidermises, Sphenostylis stenocarpa possesses paracytic stomata on the abaxial surface and anisocytic stomata on the adaxial. The abaxial surface of Centrosema pubescens possesses anomocytic and paracytic stomata and anomocytic stomata on the adaxial surface. Cell shapes of the foliar epidermal surfaces are irregular with undulate anticlinal wall patterns except on the adaxial surface of Sphenostylis stenocarpa with pentagonal cell shape and straight anticlinal wall. The two taxa are similar in their leaf type and arrangement but differ greatly in their stomatal types.

Approaches and challenges of traditional institutions in conservation of biodiversity: Implications for sustainable management of natural resources in Nigeria

The study assessed indigenous practices and beliefs on the conservation of natural resources in Oju Local Government Area of Benue State. Purposeful and simple random sampling was applied to determine the study sample and thus a sample size of 118 was used for the study. The findings revealed that majority of the respondents were male (75.4%) while 24.6% were female. The indigenous and traditional beliefs in the protection of natural resources in the area is reflected in a variety of their practices which included sacred groves and sacred landscapes, construction of masquerades and other traditional artifacts, reflecting greatly the population of the forest resources. The most conserved fauna and flora species identified were; Smutsia gigantea, Elgaria coerulea, Ceyx erithaca, Milvus aegyptius, Centropus steerii and Ophiophagus hannah; Vitellaria paradoxa, Khaya grandifoliola and Abies balsamea. Major challenges identified were; lack of inclusion by governance institution with (98.7%), followed by adoption of other religious beliefs with (97.5%), poaching/illegal logging and population growth/urbanization (91.5%), perception of idolatry (88.9%), Bush fires (89.8%) while frequent use of herbs for traditional medicine (83.1%) had the least percentage. On the ways of improvement was awareness creation had the highest proportion (33.9%), followed by attitudinal change (30.5%), while resource allocation to traditional leaders and integration of traditional conservation in formal resource conservation had the least proportion of 17.8%. It was concluded that traditional practices and beliefs if well managed will enhanced proper conservation and management of natural resources. The study thus recommended that, institutions responsible for conservation of natural resources should be positioned for effective performance and service delivery. Government should have monitoring agents that will help in ensuring natural resource conservation.

Host plant resistance against yellow stem borer and rice leaf folder through varietal screening of rice

Rice plant is attacked by many insect-pests of which yellow stem borer (dead heart at vegetative stage and white ear head at reproductive stage) and leaf folder are considered as prime devastator, responsible for major economic loss. To combat this problem, resistant varieties of rice are required for better production as well as better productivity. Host plant resistance is very much effective in integrated pest management (IPM) system, where negligible pesticidal hazard is present as well as environmental safety, low cost farming by without or minimum pesticide application and proper identification of resistant varieties for selection as parent in crossing programme to develop resistant varieties in future. The 78 rice varieties were screened out against Scirpophaga incertulas (yellow stem borer) and Cnaphalocrocis medinalis (rice leaf folder) of rice during Kharif, 2010-2012 at Rice Research Station, Chinsurah, Hooghly, under Government of West Bengal. The experiment was carried out to determine the level of resistance in early, mid-early, medium and late duration rice varieties, and shallow and semi-deep rice varieties. The pest infestation level was determined by counting dead heart, white ear head and damaged/folded leaves. The experimental results revealed that the early duration variety viz. Narendra 97 and IR 50, the mid-early duration variety i.e. IR 64 and IET 17904 proved resistant against both yellow stem borer (dead heart) and leaf folder. The medium duration variety, Ranjit was highly resistant against both yellow stem borer (dead heart) and leaf folder, and the variety, Pratiksha showed a fair degree of resistance against both yellow stem borer and leaf folder; while Jarava, the late duration variety exhibited high degree resistance against yellow stem borer (dead heart and white ear head). Besides, the varieties, Sashi and Giri recorded very low level of infestation of both lepidopteran pests while shallow and semi-deep variety such as Sashi was also considered resistant against the noxious pests.

Soil chemical properties and growth performance of white seed melon (Cucumeropsis mannii Naudin) influenced by combined soil amendments in Ile-Oluji, Nigeria

Field experiment was conducted to study the effects of crop residues in combination with NPK fertilizer (NPKF) on soil chemical properties and growth performance of white seed melon at Ile-Oluji, Ondo State Nigeria. The experiment involved applications of cocoa bean husk (CBH), cocoa pod husk (CPH), cocoa pod waste (CPW), kola pod husk (KPH), Tithonia diversifolia (weed much (WM) in combination with NPK 15:15:15 Fertilizer to produce twelve treatments at 4 t ha-1 CBH + 200 kg ha-1 NPKF, 4 t ha-1 CBH + 100 kg ha-1 NPKF, 4 t ha-1 CPH + 200 kg ha-1 NPKF, 4 t ha-1 CPH + 100 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 100 kg ha-1 NPKF, 4 t ha-1 KPH + 200 kg ha-1 NPKF, 4 t ha-1 KPH + 100 kg ha-1 NPKF, 2 t ha-1 WM + 200 kg ha-1 NPKF, 2 t ha-1 WM + 100 kg ha-1 NPKF, 300 kg ha-1 NPKF and control, all the amendments tested significantly improved soil chemical properties and growth performance of white seed melon relative to control. Three cocoa plants residues in combination with NPKF at reduced rates 4 t ha CBH + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF and 4 t ha-1 CPH + 200 kg ha-1 NPKF respectively significantly (p < 0.05) improved soil pH, organic matter (OM), available P, exchangeable k, Ca and Mg, Na, Fe, Al and ECEC among the amendments tested. All treatments increased number of leaf, branches and vine length of white seed melon compared to control. 4 t ha-1 CBH + 200 kg ha-1 NPKF, 4 t ha-1 CPW + 200 kg ha-1 NPKF, 4 t ha-1 CPH + 200 kg ha-1 NPKF, had highest value of crop branches.

Pollen analysis of animal coprolites recovered from vegetation mounds in El-Ga’ab paleolake: evidence for vegetation history of the desert of northern Sudan

In arid zones vegetation mounds are natural indicators for land degradation. Studying plants and animals remains in different strata of these mounds provide information about the past land use in which parts of the natural environment were modified into arable fields and pastures. They are suitable sites for preserving animal coprolites. In this study, two samples of different animal coprolites were collected from vertical trenches in vegetation mounds of Um Hilal and El-Hamra areas of El-Ga’ab depression in northern Sudan. Pollen grain analysis was conducted and eleven species that belong to eight families were identified. Five species recorded for El Hamra area and nine species were identified for Um Hilal area. Most of the pollen grains were identified as Suaeda monoica and Salsola imbricata which are halophytes indicates habitats of high soil salinity in El-Ga’ab depression. These species are still dominant in other law elevated areas of less dry sand dunes. Polygonum sp. Pollens were recorded in Um Hilal area indicating a moist habitat. Record of the comparatively large number of tree pollen grain of Acacia ehrenbergiana indicates no change in the dominant tree species. Presence of the pollen grains of Triticum sp. (wheat) and Heliotropium parciflorum is an evidence for past agricultural activities. This study recommended further intensive investigations of the old dry vegetation mounds distributed in the desert of northern Sudan to reconstruct its palaeoenvironment.

Impacts of long-term disturbance on soil health with relation to vegetation distribution in a tropical ecosystem

Land-use and land-cover changes are the main cause of soil degradation and associated human and environmental problems. The study was conducted in Mai Mahiu ecosystem, Kenya whose aim was to assess long-term (1985 to 2015) impacts of land-use and land-cover changes on soil health with disturbance-induced vegetation distribution. Landsat archive was utilized to detect land-use change for 30 years at an interval of 15 years and analysed based on supervised image classification. Four land-use practices (undisturbed forest, disturbed forest, cropland and grassland) were selected and soil sampled to 15 cm depth for soil analyses. In this period, cropland increased by 135% at the expense of natural forest while built-up areas increased by three times. Soil bulk density increased significantly (p<0.001) from 0.93±0.02 g cm-3 in forest soil to 1.27±0.02 g cm-3 in disturbed grassland. Soil pH had significant change (p=0.002) that ranged between 6.19±0.14 and 7.18±0.12. Soil organic carbon declined significantly (p=0.008) with land-use change with losses of up to 63% recorded in disturbed grassland. Total nitrogen levels declined from 0.34% in the forest to 0.15% in disturbed grassland soil. The pronounced changes in land-use and land-cover in Mai Mahiu have negatively affected the soil health with a potential drop in soil productivity and ecosystem provisioning. An integrated approach, enforcement of relevant laws and policy implementation are recommended to restoring and maintaining soil quality of this ecosystem.

Problematic on the use of synthetic pesticides against insect pests of tomato, (Lycopersicon esculentum Mill.) in Foumbot, Western Region of Cameroon

An inventory of pest insect of tomato (Lycopersicon esculentum) was carried out in 2018 in five localities of Foumbot production area to find out the effects of using synthetic insecticides on the worrying insects. The quantity applied and frequency of application was equally assessed and compared to those prescribed by the producers. Caiman B, Cypercal, Parastar, Cybemex and Plusfort are used. The insects were captured weekly during March and February during fruits formation and when they are getting ripe. The results showed that the doses and the frequencies of applications are different from a producer to the other. A total of 6485 insect pests belonging to the order Diptera, Hemiptera and Lepidoptera were captured. The greatest number of insect pests was captured in the locality of Mangoum 1 (19.75%). Bemisia tabaci (Hemiptera: Aleyrodidae) was the most abundant species (62.94%). The damages bring a setback in quantity and quality of the harvest, fruits are not good any more for consumption. The usage of these pesticides without respecting the norms has not reduced the population of the insect pests of tomato at Foumbot, showing that the insects became resistant. We suggest a strict respect of the doses and frequencies and the use of bio-pesticides and essential oils, respectful of the environment.