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1.
Mohammed Moro Buri Roland Nuhu Issaka Toshiyuki Wakatsuki 《Soil Science and Plant Nutrition》2005,51(5):755-759
A review of soil acidity problems with regards to causes, extent and management in Ghana shows that the extent of soil acidity has changed within a period of 2–3 decades. In the 1970s' soil acidity was a major problem in the Western region and the lowlands. Oxisols and Ultisols are common soils found in this area. However, anthropogenic causes have augmented natural causes resulting in more low pH soils. Soil acidity has therefore become a serious problem throughout the country. Anthropogenic causes identified include general agronomic practices such as tillage, use of mineral fertilizers and continuous cultivation. Rates of 1–2 t ha−1 lime on ultisols and oxisols in Ghana are more than adequate to meet the calcium demands and sufficient to neutralize residual acidity of any nitrogen fertilizer. Addition of organic amendments on low pH soils was also found to be beneficial and resulted in increased yields. The adoption of the "sawah" technology for lowland rice production has also resulted in improved water management, increased nutrient availability and significant increases in rice yields. 相似文献
2.
沿铺面道路和未铺面道路,调查了4种路边环境（缓变区,附近区,中间区和非缓变区）的Pteleopsis suberosa苗木种群结构和其更新机制。沿道路平行线调查了2m×5m的203块样方,记录每个样方内的种苗总数和每个种苗的活枝数。通过评价基部和水平枝芽和挖掘地下根系来确定更新机制。结果表明,在4种路边环境中,单一主干和多主干苗木的总密度及各自密度都有明显的变化（p〈0.05）。所有苗木都是无性繁殖而来,根出条占98%,眠芽蘖和萌生各占1%左右。研究表明,铺面道路和未铺面道路缓变区中等水平土壤的干扰可以刺激Pteleopsis suberosa根出条更新 道路类型（铺面和未铺面）对苗木密度没有影响,但对路边立地的P.suberosa种群的萌生能力来说,道路类型是一个重要变量。P.suberosa是一个耐干扰的物种,受道路网干扰后可以通过根出条繁殖。 相似文献
3.
Marney E. Isaac Eric O. Adjei Roland N. Issaka Vic R. Timmer 《Agroforestry Systems》2011,81(2):147-155
Shade tolerant species response to nutrient additions and light regulation by canopy trees in perennial agroforestry systems
has been well documented. However, accelerated early growth, particularly in cocoa-shade systems, may be offset by competition
for limited resources on nutrient poor sites. To date, few agroforestry management strategies focus on nutrient manipulation
of the shade tree component or strategies for precision nutrient application. Our research objective was to diagnose interactions
between nutrient supplied shade trees intercropped with cocoa. We established greenhouse trials in Kwadaso, Ghana cultivating
Terminalia superba seedlings with four fertility treatment levels: conventional rate (current practices) under linear additions, and half, full
and double conventional rate under exponential additions (steady-state nutrition) to determine maximal growth and nutrient
uptake. After 4 months of additions in the nursery, pre-fertilized T. superba seedlings were then out-planted into field trials with cocoa seedlings. After 4 months of intercropping, cocoa associated
with half rate exponentially supplied T. superba had significantly larger leaf area, greater leaf number, and higher nutrition (N and P uptake) than cocoa associated with
full rate conventionally supplied T. superba. This may be attributed to (1) more favorable light conditions under these taller shade seedlings and (2) the internal use
of nutrients associated with exponentially supplied T. superba seedlings, which lowered stress on native soil resources. The latter is corroborated with our findings on soil fertility
status. This strategy focused on reducing fertilizer inputs and developing precise plant nutrition technology for on-farm
use. Our findings suggest that shade seedlings under steady state nutrition can mitigate early growth competition in the field. 相似文献
4.
Fidèle Bognounou Mulualem Tigabu Patrice Savadogo Adjima Thiombiano Issaka Joseph Boussim Per Christer Oden Sita Guinko 《Annals of Forest Science》2010,67(3):306-306
5.
Loyapin Bondé Oumarou Ouédraogo Issaka Ouédraogo Adjima Thiombiano Joseph I. Boussim 《Plant Production Science》2013,16(2):143-158
ABSTRACT Shea tree (Vitellaria paradoxa) is one of the main native oil plants with high economic value in Africa. Its fruits are used for food, medicinal, cultural and exportation purposes. However, the lack of efficient tools to assess annual fruit production of the species limits the sustainable management of its resources. Therefore, production statistics are useful to organize the activities of the shea sector. This study aimed to (i) assess the interannual variation in fruit production along a climatic gradient in Burkina Faso, (ii) examine fruit production patterns according to climatic zones and tree size, (iii) assess the contribution of high-yielding trees in the annual potential production and (iv) develop allometric equations for estimating fruit yields of the species. The yield of 212 trees distributed across three climatic zones was monitored over four successive years. Within each climatic zone, fruit production was significantly different among years. Fruit production was positively and significantly correlated with tree size. The interannual variation in fruit production at tree individual level was higher in drier climatic conditions. The mean interindividual synchrony was less than 50% in each zone, suggesting a large range in fruit production patterns of the species. Annually, more than 55% of the total fruit production was supported by high-yielding trees. The best regression models for estimating fruit yields had R 2 values of 69–73% with prediction errors ranging from ?7% to 4%. Our findings are useful tools for the planning of rational exploitation of shea tree’s resources and its sustainable management. 相似文献
6.
Aristide Mahoutin Agbokounou Gbênangnon Serge Ahounou Issaka Youssao Abdou Karim Guy Apollinaire Mensah Bénoît Koutinhouin Jean-Luc Hornick 《Tropical animal health and production》2017,49(2):287-294
The effect of bovine colostrum, including its thermally labile compounds, on the survival and growth performance of local breed piglets reared by their mother, in Benin, was evaluated over a 49-day trial. Three groups of 16 piglets, stemming from two primiparous sows belonging to a unique traditional farm, were respectively fed for the first 48 h of life with either bovine colostrum heated to 85 °C for 30 min, or thawed bovine colostrum, or colostrum from the mother. Thereafter, the animals that received bovine colostrum turned back to their mother. At day 21, almost all piglets from the group that received heated colostrum died. The highest total weight gain was obtained in the group that received thawed bovine colostrum (P???0.01), followed by the group left with the mother. Corresponding average daily gains (ADGs) were 56, 34 and 2 g/day, respectively (P???0.05). At the end of the trial, the treatment effect was highly significant on the survival of piglets (100% in the thawed colostrum group vs. 00 and 50%, respectively, in the heated colostrum group and in the group left with the mother). At day 49, numerically higher weight and ADGs were obtained in the group that received thawed cow colostrum. Thawed bovine colostrum improved the growth performance and piglet survival in the local pig breed in Benin, probably owing to thermally labile components. Bovine colostrum may be used in our farms in order to reduce pre-weaning mortality, improve the profitability of livestock farmers, and ensure survival of traditional farms. The use of bovine colostrum on farms could be facilitated by collaboration between pig farmers and bovine farmers. It could also be facilitated by the creation of a colostrum bank. 相似文献
7.
Dotché Ignace Ogoudanan Bankolé Constant B. O. Dahouda Mahamadou Biobou Rodrigue Bonou Gabriel A. Antoine-Moussiaux Nicolas Dehoux Jean-Paul Thilmant Pierre Mensah Guy Apollinaire Koutinhouin Benoît G. Youssao Abdou Karim Issaka 《Tropical animal health and production》2020,52(2):687-698
Tropical Animal Health and Production - Benin’s domestic production of pork is deficient because of the animals’ low productivity. This study aimed to evaluate the zootechnical... 相似文献
8.
Characterization of a Spontaneous Rapeseed Mutant Tolerant to Sulfonylurea and Imidazolinone Herbicides 总被引：1，自引：0，他引：1
A spontaneous chlorsulfuron tolerant variant, RCS-5, was isolated from protoplast culture of rapeseed, Brassica napus L. The tolerance level of the mutant was due to mutation of a single dominant gene resulting in an alteration of the acetolactate synthase enzyme. Seedling growth bioassays applied in vitro or after seed-soaking treatment showed that the mutant was 250——500 more tolerant to chlorsulfuron than the sensitive control. Field tolerance was evaluated with commercial formulations of chlorsulfuron (Glean T), triasulfuron (Kéos), and metsulfuron methyl (Allié), and an imidazolinone imazamethabenz (Méganet). The results indicated that the mutant could tolerate a lower dose rate of sulfonylureas than the dose recommended for cereal culture. In contrast, the mutation provided a good protection against imazamethabenz. The possibility of using the protoplast-derived mutation in crop rotation and F1 hybrid seed purity assessment is also discussed. However, isolated lines of the mutant were found to be less productive and one week later than the sensitive parent. 相似文献
9.
Vitellaria paradoxa C. F. Gaertn., commonly known as shea tree or Vitellaria, is ranked the most important tree species of the savannah regions in the most African countries due to its ecological and economic importance for livelihoods and national economies. However, the savannah regions are the most vulnerable areas to the global climate change. Moreover, the Vitellaria populations on farmlands are threatened by the dominance of old trees with low or lack of regeneration. In this study both morphological and genetic diversity were assessed using several phenotypic traits and 10 microsatellite markers, respectively, to assess the impact of land use and agro-ecozone types on Vitellaria in Ghana. The land use types were forests and farmlands, and the agro-ecozone types included the Transitional, Guinea, and Sudan savannah zones. The mean values of morphological traits, such as diameter at breast height (DBH) and canopy diameter (CD), were statistically different between forest (DBH = 22.20, CD = 5.37) and farmland (DBH = 39.85 CD = 7.49) populations (P < 0.00001). The Sudan savannah zone with mean petiole length of 4.96 cm showed significant difference from the other zones, likely as a result of adaptation to drier climate conditions. Genetic data analysis was based on 10 microsatellite markers and revealed high genetic diversity of Vitellaria in Ghana: mean expected heterozygosity, H e was 0.667, and allelic richness, measured as number of effective alleles A e , was 4.066. Both farmlands and forests were very diverse indicating lack of negative influence of farmer’s selection on genetic diversity. Fixation index was positive for all populations (mean F IS = 0.136) with farmlands recording relatively higher values than forests in all ecological zone types studied, probably indicating less gene flow in the farmlands. Moderate differentiation (F′ ST = 0.113) was comparable to other similar tree species. Both land use and ecological zone types influenced genetic differentiation of Vitellaria at varying levels. The species was spatially structured across three ecozones and following climatic gradient. The forest reserves are used in situ conservation for Vitellaria in Ghana. High diversity observed in the most arid zones provides opportunity to find and use appropriate plant materials for breeding climate change resilient trees. 相似文献
10.
Benjamin Lankoandé Amadé Ouédraogo Joseph Issaka Boussim Anne Mette Lykke 《Agroforestry Systems》2017,91(1):85-96
Non Timber Forest Products play an important role as source of food and income generation in developing countries. In Burkina Faso, many wild tree species provide various useful products, among them the local oil tree, Lophira lanceolata which occurs in the western part of the country. This study aimed at assessing the habitat diversity and population structure of L. lanceolata’s natural stands according to land cover types. Two sites were considered: Banfora, where the use value of fruits is unknown and Orodara, where fruits are exploited for oil production. A stratified and oriented sampling scheme based on the occurrence of L. lanceolata and land cover was applied using rectangular plots of 50 m × 20 m. Phytosociological and quantitative inventories were carried out to assess the woody species diversity of stands and L. lanceolata population structure, respectively. Species diversity indices, structural parameters were computed and analyses of variance, Chi square test were performed to compare sites according to land cover types. The results showed high woody species diversity associated with L. lanceolata stands (H = 3.2–3.6). The densities of L. lanceolata ranged between 94 and 280 trees per hectare, with significant differences between land cover types and sites. The population pattern showed a good regeneration potential and high resource availability. L. lanceolata was fairly resilient to human pressure and tended to recolonize disturbed lands. With a high potential for sustainable management, L. lanceolata is a promising NTFP species which can contribute to improve the local and national economy. 相似文献