Evaluating Plant Leaf Tinctures against Maize Weevils (Sitophilus zeamais Motsch.) in Stored Maize (Zea mays L.) under Laboratory Conditions

Maize weevils (Sitophilus zeamais Motschulsky) are commonly stored grain pests of economic importance in several parts of Africa. A huge amount of synthetic pesticides is being used for the management of crop pests, which have many negative effects on the biotic and abiotic components of the environment. Plant-derived pesticides, on the other hand, are safe for the environment, affect only target insects, have a low application cost, and are easily biodegradable. The purpose of this research was to determine the effectiveness of ethanol leaf tinctures of four selected botanicals against S. zeamais: Brucea antidysenterica (J.) (Waginos), Croton macrostachyus (Hochst.) (broad-leaved croton), Nephrolepis exaltata (L.) (Boston fern), and Carica papaya (L.) (papaya). The experiment was carried out in a completely randomized design (CRD) with four different concentrations (0 mL, 2.5 mL, 5 mL, and 7.5 mL) and four plant leaf tinctures in three replicates. A random sample of 300 g of clean maize seed was treated with the four selected botanicals in plastic jars covered with a muslin cloth. Twenty adult maize weevils were introduced into each disinfected, treated, and untreated maize grain. The mortality rate, grain damage, and F1 progeny emergences were assessed and analyzed using SPSS software version 25. The highest (100%) mortality rate of S. zeamais was recorded for maize seeds treated with the leaf tincture of B. antidysenterica, followed by maize seeds treated with the leaf tincture of C. papaya (97.5%) at an application rate of 7.5 mL/300 g. The mean weight loss of the seeds showed a significant variation between the treatments. The mean weight loss of the seeds in the control (8.96%) was higher than the total mean weight loss treated by all plant leaf tinctures (3.66%). The emergence of F1 progeny of S. zeamais on maize grains showed significant differences among the treatments. The highest emergence (100%) of F1 progenies was recorded for the control treatment followed by C. macrostachyus (16.65%) at a rate of 2.5 mL/300 g maize grain treatment. The study concluded that B. antidysenterica and C. papaya tinctures had the potential to control the infestation of maize grains by S. zeamais

People's attitudes and perceptions towards area enclosure in Ethiopian central rift valley: Implications for land restoration and livelihood improvement

Land degradation is a common environmental problem affecting the ecological functions and ecosystem services leading to biodiversity loss and impoverishment of rural livelihood. This study explores people's attitudes and perceptions in central rift valley, Ethiopia. We interviewed 384 households using semi-structured questionnaires, conducted focus group discussions, and key informant interviews. The results showed that 92.1% of the respondents were aware of the role of area enclosure in degraded land restoration; 94.5% had a positive opinion of the establishment of new enclosures; 94.5% agreed to maintain the existing enclosures whereas 88.1% support the expansion. The benefits gained from the enclosure increased significantly with increased vegetation cover (OR = 41.961, P < 0.001). An improvement in the local communities' attitude towards the area enclosure is directly correlated with the economic benefits they obtain from the enclosures. Our results showed that farmers were optimistic to perceive that area enclosure plays a positive role to restore degraded lands thereby improving the livelihood of the local community. We found that the socioeconomic profile of farmers affects their attitude, and perception of the role of area enclosure to improve and restore the degraded area

Elucidating woody vegetation patterns in relation to soil and topography in tropical Africa : the case of Nech Sar National Park (Ethiopia)

Background and aims - Although soils and topography are reported to be key factors determining vegetation patterns, there are very few studies on this topic in tropical Africa. Given the young nature of the soils of Nech Sar National park, we hypothesised that the woody vegetation would be related to both topsoil and subsoil characteristics. As topography also determines soil characteristics, we investigated whether soil and topography could be considered independently. Methods - Abundance of woody plant species was measured in 19 stratified randomly selected plots of 20 m x 20 m. At the centre of each plot a soil profile pit was dug and samples were taken from each horizon. Topographic characteristics were derived from a 30 m x 30 m digital elevation model. TWINSPAN and Detrended Correspondence Analysis (DCA) were used to identify major patterns in species composition. Factor Analysis was used to assess the variability of, and correlation between, the soil characteristics. Differences between the vegetation groups in-terms of stand and environmental characteristics was tested with the Maim-Whitney U test. DCA axes describing the major variation in vegetation patterns were correlated with soil and topographic characteristics. Results - Forest vegetation was found on Fluvisols and Gleyic Cambisols while bushland was found on Andosols and Vertic Cambisols. The vegetation gradient from forest to bushland (DCA-1) was correlated with both topsoil and subsoil characteristics reflecting parent material and alkalinity; these could however not be dissociated from topography. In contrast, variation both within the forest and the bushland (DCA-2) was not correlated with environmental characteristics. We attribute this variation to disturbances such as collection of firewood or logging, and to the absence of large browser or scarcity of wildfires. Conclusions - This study calls for giving equal attention to topsoil and subsoil for elucidating woody vegetation patterns. Though vegetation patterns vary with topography, a comprehensive understanding requires insights into soils

Elucidating woody vegetation patterns in relation to soil and topography in tropical Africa: the case of Nech Sar National Park (Ethiopia)

Background and aims – Although soils and topography are reported to be key factors determining vegetation patterns, there are very few studies on this topic in tropical Africa. Given the young nature of the soils of Nech Sar National park, we hypothesised that the woody vegetation would be related to both topsoil and subsoil characteristics. As topography also determines soil characteristics, we investigated whether soil and topography could be considered independently. Methods – Abundance of woody plant species was measured in 19 stratified randomly selected plots of 20 m × 20 m. At the centre of each plot a soil profile pit was dug and samples were taken from each horizon. Topographic characteristics were derived from a 30 m × 30 m digital elevation model. TWINSPAN and Detrended Correspondence Analysis (DCA) were used to identify major patterns in species composition. Factor Analysis was used to assess the variability of, and correlation between, the soil characteristics. Differences between the vegetation groups in-terms of stand and environmental characteristics was tested with the Mann-Whitney U test. DCA axes describing the major variation in vegetation patterns were correlated with soil and topographic characteristics. Results – Forest vegetation was found on Fluvisols and Gleyic Cambisols while bushland was found on Andosols and Vertic Cambisols. The vegetation gradient from forest to bushland (DCA-1) was correlated with both topsoil and subsoil characteristics reflecting parent material and alkalinity; these could however not be dissociated from topography. In contrast, variation both within the forest and the bushland (DCA-2) was not correlated with environmental characteristics. We attribute this variation to disturbances such as collection of firewood or logging, and to the absence of large browser or scarcity of wildfires. Conclusions – This study calls for giving equal attention to topsoil and subsoil for elucidating woody vegetation patterns. Though vegetation patterns vary with topography, a comprehensive understanding requires insights into soils.status: publishe

Mapping soils from terrain features – the case of Nech Sar National Park southern Ethiopian Rift Valley

Current soil maps of Ethiopia do not represent accurately the soils of Nech Sar National Park. In the framework of studies on the ecology of the park, we prepared a new soil map based on field observations and a digital terrain model derived from SRTM data with a 30-m resolution. The landscape comprises volcanic cones, lava and basalt outflows, undulating plains, horsts, alluvial plains and river deltas. SOTERlike terrain mapping units were identified. First, the DTM was classified into 128 terrain classes defined by slope gradient (4 classes), relief intensity (4 classes), potential drainage density (2 classes), and hypsometry (4 classes). A soil-landscape relation between the terrain mapping units and WRB soil units was established based on 34 soil profile pits. Based on this relation, the terrain mapping units were either merged or split to represent comprehensive soil and terrain map. The new soil map indicates that Leptosols (30 %), Cambisols (26 %), Andosols (21 %), Fluvisols (12 %), and Vertisols (9 %) are the most widespread Reference Soil Groups of the park. In contrast, the harmonized soil map of Africa derived from the FAO soil map of the world – indicates that Luvisols (70%), Vertisols (14%) and Fluvisols (16%) would be the most common Reference Soil Groups. However, these latter mapping units are not consistent with the topography. This case study shows that with the now freely available SRTM data, it is possible to improve current soil information layers with relatively limited resources, even in a complex terrain as Nech Sar National Park.status: publishe