Domestication of Dacryodes edulis: 1. Phenotypic variation of fruit traits from 100 trees in southeast Nigeria

A participatory approach to tree domestication is being pioneered by ICRAF and international partners in Cameroon and Nigeria. The domestication of Dacryodes edulis offers opportunities to improve the livelihoods of subsistence farmers and to diversify farming systems, such as cocoa farms. The trees produce marketable fruits as well as shade for cocoa and coffee. Twenty-four ripe fruits were collected from each of 100 D. edulis trees in Mgbuisi, southeast Nigeria by subsistence farmers. There was continuous and significant tree-to-tree variation in fruit mass (10.2±0.5–71.4±1.3 g), flesh mass (6.8±0.3– 62.2±1.2 g) and kernel mass (1.3±0.5–15.1±0.4 g). Mean fruit mass did not differ significantly between different land uses. Flesh mass:kernel mass ratio varied from 0.79 to 29.0. Two trees had fruits without kernels. There was also continuous and significant tree-to-tree variation in fruit length (39.0±0.6– 95.1±1.2 mm), fruit width (21.82±0.16–43.75±0.33 mm) and flesh thickness (1.82±0.1–6.39± 0.1 mm). Fruit length:width ratio varied from 1.35 to 3.18. Cooked fruits varied in taste with only 14% of trees getting the highest score. Similarly, fruits varied in oiliness with only 3% of trees getting the highest score. Thirteen skin colours were recorded, with the most common being dark blue (31%), greyish violet (29%) and deep blue (9%). Ninety-nine percent of the trees had been planted, with 57% in homegardens, 22% in crop fields, 17% in fallow land and 4% in cocoa. Tree height ranged from 4 to 22m, and DBH from 9.55 to 63.65 cm. Tree age ranged from 5 to 64 years. Farmers reported first fruiting from age 3 up to 22 years (average of 9.4 years). Most trees originated from seeds bought in markets (63%). Market prices of fruits from different trees, ranged from 2 to 12 fruits for 10 Naira (US0.07). These quantitative results will help in the identification of elite trees of D. edulis for cultivar development through clonal propagation.     

The scope and potential of tree legumes in agroforestry

Tree legumes play a vital role in many agroforestry systems currently in use throughout the world. Because of their multipurpose nature they can be used to provide high quality fodder for livestock, nutrient rich mulch for crops, fuelwood and timber, microenvironment amelioration, ecosystem stability, and human food.Tree legumes are increasingly being used to provide fodder for livestock, as they have a number of unique characteristics which make them attractive for both smallholder and largescale livestock enterprises. Research and development efforts have concentrated on broadening the resource base by evaluating a greater range of tree legume genera, defining optimum management strategies, and developing appropriate systems which capitalize on the advantages of these species.This paper reviews the role of tree legumes in agroforestry, especially for fodder purposes, outlines the areas of current research focus, and endeavors to highlight some gaps in our knowledge which require further research effort.     

Agroforestry potential in the southeastern United States: perceptions of landowners and extension professionals

The first steps in developing an agroforestry extension and training program involve compilation, synthesis, and analysis of current knowledge on existing practices. Equally important is to understand the perceptions of landowners and professionals of agroforestry as a land use option. No systematic effort has been made to assess these critical issues in the southeastern United States. Therefore, needs assessment surveys were developed following an analysis of major demographic issues that frame land use in the region and synthesis of information obtained from informal site visits and interviews with people engaged in resource and land use in the Atlantic and Gulf Coastal Plain. Surveys of extension professionals and landowners were then undertaken in the states of Alabama, Florida, and Georgia to represent the southeastern region. In addition to getting insights into the perceived benefits and concerns about agroforestry practices, the surveys indicated that the extent of alley cropping, forest farming and silvopasture practiced by landowners was less than anticipated, and that the prominence of windbreaks was overlooked by professionals. Managed riparian forest buffers or streamside management zones and windbreak technologies were the most widely used forms of agroforestry in the study area, although landowners did not recognize influence of agroforestry practices on quality or quantity of water among benefits of highest importance to them. Multistrata patio- or home gardens were also a prominent landowner-practice and acknowledged by professionals. These survey results can be useful for developing a relevant agroforestry extension and training program in the subtropical Southeast and may be of interest to agroforestry efforts in other similar settings. This revised version was published online in August 2006 with corrections to the Cover Date.     

Agroforestry systems in the Garhwal Himalayas of India

Agroforestry systems, though at subsistence level are well established in Garhwal Himalayas. The farmers undertake cultivation of various crops, seasonal and biennials crops with trees all in mixtures on the same piece of land. Farm animals and poultry form an essential component of the systems. The intimate association of different species provides both subsistence and commercial products which give additional income to the farmer. The paper describes the general scenario of socio-economic condition and existing agroforestry practices and some suggestions for their improvement in the Garhwal Himalayas.     

Weed seedbank characteristics of arable fields under different fallow management systems in the humid tropical zone of southeastern Nigeria

The composition and pattern of weed flora in arable fields are determined by their seedbank structure; but the influence of fallow management practices on weed seedbank structure is presently unknown. The objective of this study was to investigate weed seedbank characteristics and weed population dynamics in arable fields in natural and planted-fallow systems. The study plots were at Mbaise, a densely populated area of southeastern Nigeria, where farmers regenerate their exhausted soils by maintaining planted fallows of Dactyladenia barteri (Hook. F. ex Oliv.) Prance & F. White, and at Umuahia, a less-densely populated area in the same region, where farmers depend on natural bush fallow for soil regeneration. The effect of three years of fallow on the weed flora of arable fields in the two fallow management systems differed remarkably. The first flush of weeds on fields that were cultivated after three years of planted D. barteri fallow (Mbaise) consisted of 80% broadleaf weeds, 7% grass weeds and 13% sedges. On the other hand, the first flush of weeds on the natural bush fallow fields (Umuahia) of the same fallow duration as the D. barteri fallow system consisted of 17% broadleaf weeds, 70% grasses and 13% sedges. Three years of planted fallow caused 36% decrease in weed seedbank at Mbaise relative to the cropped field while the same duration of natural bush fallow caused a 31% increase in weed seedbank at Umuahia. These results show that the planted D. barteri fallow system has a higher potential to reduce weed pressure in smallholder agriculture than the natural bush fallow system and may explain in part why farmers in this humid forest zone have adopted the practice. This revised version was published online in June 2006 with corrections to the Cover Date.     

Agroforestry for water management in the cropping zone of southern Australia

Agroforestry has been advocated as a means of managing excess water that has accumulated in the agricultural landscape of southern Australia since clearing of native vegetation. This article examines the feasibility and profitability of agroforestry systems designed to manage rising, saline watertables. A framework for Australian conditions is described that considers the interactions between trees, crops and their below ground environment and how they influence water use, crop yield and profitability. Data is presented from a study of a commercial scale agroforestry system under ideal conditions where trees have access to a shallow fresh water table. The discussion is then broadened to encompass soil, relief and ground water conditions more typical of the southern Australian cropping zone. The relative merits of segregating, integrating and rotating trees with crops are then examined. It is concluded that, in most cases, trees would need to be widely dispersed over a significant proportion of the landscape to manage deep drainage and salinity. Agroforestry is therefore only likely to be an effective solution to water management where trees can compete directly on commercial terms with conventional agriculture. Given the generally low rates of biomass accumulation in semi-arid woody species, this presents a significant challenge for agroforestry in the cropping zone of southern Australia. This revised version was published online in June 2006 with corrections to the Cover Date.     

Initial agronomic evaluation of Parkia biglobosa in the humid zone of Nigeria

Parkia biglobosa is an important traditional economic tree legume of considerable multipurpose potentials that has not been well researched. It is used for fodder, human food, fuel wood, timber, green manure, medicine, provides shade for forage grasses and livestock and protects soil from heat and it is important in soil nutrient cycling.The objective of this study was to determine the effect of management regimes (cutting frequency and height) on the coppicing ability, fodder production, and nutritive value potentials of cultivated Parkia trees. This initial study has shown that the tree has a potential as fodder for livestock as well as human food and should be further studiedto fully understand its biology, agronomy and feeding value under various agroforestry or silvopastoral systems of humid tropics in West Africa.     

Early growth and seasonal chemical composition of three indigenous multipurpose tree species (MPTS) in Abeokuta,Nigeria

A study was carried out to evaluate the growth parameters and nutritive qualities of Moringa oleifera, Millettia griffoniana and Pterocarpus santalinoides. The main objective of the study was to assess the potential of the MPTS in supplementing the feed of ruminant animals during the dry season when grasses are scarce and their quality generally fall short of animal requirements. Leaf samples were randomly collected from the trees for estimation of the proximate composition, neutral detergent fibre, acid detergent fibre and gas production using the in vitro technique. Samples were collected three times to represent seasonal variations as follows: November: Early Dry; February: Mid Dry and April: Late Dry seasons. Gas production was recorded at 3, 6, 9, 12, 15, 18, 21, 24, 48, 72 and 96 h of incubation. Mortality rate was less than 5%. M. oleifera recorded the best overall growth respectively followed by P. santalinoides and M. griffoniana. P. santalinoides and M. oleifera retained more leaves in the dry season than M. griffoniana. The dry matter (DM) and ether extract (EE) contents of the MPTS were significantly (P < 0.05) affected by seasons and plant species while there were significant (P < 0.05) species effects on the CP and ADF values. The gas production values and the fermentation parameters indicated the presence of potentially degradable nutrients in the MPTS, which underscores the importance of the tree species as sources of nutrient for ruminant animals during the dry season.     

Predicting the decomposition patterns of tree biomass in tropical highland microregions of Kenya

Decomposition- and nitrogen-release patterns of biomass from three agroforestry multipurpose trees (Calliandra calothyrsus, Cordia africana and Grevillea robusta) were investigated in four contrasting environments (microregions) in the Kenyan tropical highlands during two cropping seasons. Dried leafy biomass was placed in 2-mm litter bags, buried at 15-cm depth and recovered after 2, 4, 7, 10, 15 and 20 weeks. Decomposition patterns were best described by first-order exponential decline curves. The decomposition rate constants ranged from 2.1 to 8.2 yr^–1, and the rates of decomposition among the species were in the order: calliandra cordia > grevillea. There was a species-by-environment interaction during both seasons, but the nitrogen released did not follow such a pattern. Among the three tree species, calliandra released the highest amount of cumulative N, followed by cordia and grevillea. Using multiple regression techniques, decomposition pattern was described as a function of three groups of factors: biomass quality (N, C, lignin and polyphenol), climate (soil temperature and rainfall), and soil conditions (pH, soil organic C, total N and P). For all the species and factors combined, the adjusted R ² values were 0.88 and 0.91 for seasons 1 and 2, respectively. Among the three groups of factors, climate and biomass quality had the most influence on decomposition rates. Climatic factors accounted for 75% of the total rate of decomposition in season 1 (irregular season with less rainfall and more soil temperature fluctuations), whereas biomass quality factors were more influential in season 2 (regular season), accounting for 65% of the total variability.Florida Agricultural Experiment Station Journal Series No. R.-05555.     

A preliminary investigation into agroforestry practices in the savanna belt of western Nigeria

This paper evaluates agroforestry practices in a part of the Guinea savanna belt of south-western Nigeria. The attitude of local farmers to tree planting in crop fields was evaluated. Tree adoption on the farm was assessed by identifying the tree species on the field and their frequencies. The results show that there is little indication that the trees are deliberately utilized to enhance farm operations in the area. It is concluded that greater attention needs to be given to the promotion of agroforestry techniques in the savanna belt. This is especially important as the increasing demand for food would put pressure on the soil resources.     

The domestication and commercialization of indigenous trees in agroforestry for the alleviation of poverty

New initiatives in agroforestry are seeking to integrate into tropical farming systems indigenous trees whose products have traditionally been gathered from natural forests. This is being done in order to provide marketable products from farms that will generate cash for resource-poor rural and peri-urban households. This poverty-alleviating agroforestry strategy is at the same time linked to one in which perennial, biologically diverse and complex mature-stage agroecosystems are developed as sustainable alternatives to slash-and-burn agriculture. One important component of this approach is the domestication of the local tree species that have commercial potential in local, regional or even international markets. Because of the number of potential candidate species for domestication, one crucial first step is the identification of priority species and the formulation of a domestication strategy that is appropriate to the use, marketability and genetic potential of each species. For most of these hitherto wild species little or no formal research has been carried out to assess their food value, potential for genetic improvement or reproductive biology. To date their marketability can only be assessed by their position in the local rural and urban marketplaces, since few have attracted international commercial interest. To meet the objective of poverty alleviation, however, it is crucial that market expansion and creation are possible, hence for example it is important to determine which marketable traits are amenable to genetic improvement. While some traits that are relatively easy to identify do benefit the farmer, there are undoubtedly others that are important to the food, pharmaceutical or other industries that require more sophisticated evaluation. This paper presents the current thinking and strategies of ICRAF in this new area of work and draws on examples from our program. This revised version was published online in June 2006 with corrections to the Cover Date.     

Variations and phenotypic correlation of growth attributes of Calliandra calothyrsus in the Blue Mountains of Jamaica

Forested land cleared for agriculture in the Blue Mountains of Jamaica rapidly loses its productivity leading to further slash-and-burn cultivation and the degradation of more forest. Contour hedgerows of Calliandra calothyrsus Meissner have been shown to reduce water runoff and soil erosion, and products of the species have a wide range of uses in the local farming community. A trial was established at 1550 m in which the locally naturalised population of C. calothyrsus was compared with seven provenances from across the species' ecological range. There was considerable variation between provenances of C. calothyrsus in all the above-ground growth variables measured and, although the local provenance performed moderately well, it was clear that there is potential to improve the suitability of the species for a range of local uses by the introduction of new provenances. One provenance combined high above-ground productivity with low fine root-length density, especially in the inter-hedgerow area: it offers particular potential for use in simultaneous agroforestry systems providing wood and foliage products whilst not imposing high levels of competition with crop plants for below-ground resources. Although there were significant differences between provenances in the distribution of roots between the hedgerow and inter-row areas, they did not differ in the distribution of roots between soil depths. There were only limited differences between provenances in the response of their subsequent growth to harvesting. However, significant block × provenance interactions suggested that the performance of C. calothyrsus provenances may be difficult to predict between sites and farmers should be encouraged to carry out trial planting of a number of provenances to find those which best match their farm environment and needs.This revised version was published online in November 2005 with corrections to the Cover Date.     

Agroforestry for soil and water conservation in the western Himalayan Valley Region of India 2. Crop and tree production

A ten-year-study (1983 to 1992) conducted on nine 15 × 90 m runoff plots at 4% slope compared production efficiency of Leucaena leucocephala and Eucalyptus hybrid based agroforestry as well as monocropping landuse systems in the warm, subhumid climate of the western Himalayan region of India. Treatments for the first sequence were: monocropping systems of leucaena, eucalyptus, Chrysopogon fulvus grass and maize – wheat rotation, and alley cropping systems of grass and crops at 4.5 and 10.5 m alley widths with paired contour tree rows of leucaena and eucalyptus. In the second sequence, alley width increased to 22.5 m in 1989, grass was replaced by turmeric Curcuma longa and paired contour rows of leucaena hedges were introduced in monocropping systems of grain crops and turmeric. Integration of leucaena and eucalyptus trees with crops caused severe reduction of crop yields ranging from 21 to 92% for wheat grain, 59 to 69% for maize grain, 60 to 67% for dry grass and about 50% for turmeric rhizome depending upon the age of trees and alley width. The grain yield of crops stabilized at about 50% reduction with 22.5 m alley width. Total crop biomass (grain + straw) also revealed a similar trend; however, its magnitude of reduction was less severe than for grain. Production of biomass was much lower near the tree rows than in mid alleys. Managing leucaena as contour hedgerows eliminated crop yield reduction in alleys. Performance of grass and turmeric in alleys was not found to be satisfactory. Biomass produced from trees adequately compensated the crop yield reduction. Land equivalent ratios of agroforestry landuses were comparable or even better than monocropping systems indicating suitability of these systems for the western Himalayan valley region. This revised version was published online in June 2006 with corrections to the Cover Date.     

Essential oil of Lindera neesiana fruit: Chemical analysis and its potential use in topical applications

The composition of the essential oil of Lindera neesiana Kurz fruit was examined by GC-MS, ¹H, ¹³C and bidimensional NMR techniques (HMQC, HMBC, COSY, TOCSY). Forty compounds were identified, representing approximately 86% of the oil: Z-citral (15.08%), E-citral (11.89%), eucalyptol (8.75%), citronellal (6.72%), α-pinene (6.63%) and β-pinene (5.61%) were the major components. The essential oil of L. neesiana fruit showed significant antimicrobial activity against Staphylococcus aureus and Candida albicans at non-cytotoxic doses in human keratinocytes, suggesting possible topical applications.     

观赏果树在南京城市园林绿化中的应用

采用实地调查结合资料收集的方法,对南京城市园林绿地中主要的观赏果树种类及园林应用形式进行了总结与分析。结果表明:南京城市园林绿化中的观赏果树主要集中在27科,总计86种2变种。其中最大的科为蔷薇科,占总数的31.8%;其次为壳斗科、胡桃科和柿树科,这4个科的种类占到总数的50%;应用形式主要有林荫类、绿篱类、攀援缠绕类、盆栽类;总结了在南京城市绿地有较大推广价值、绿化效果良好的观赏果树种类;并提出其合理开发、利用的建议。     

甘肃子午岭林区野生果树种质资源调查研究

根据初步调查,甘肃子午岭野生果树有94种(变种、亚种、变型),隶属22科38属,其中蔷薇科40种,忍冬科11种,为该区的优势科。同时,提出了野生果树资源合理开发、保护利用及可持续发展的建议。     

Growth and fruit production of Sclerocarya birrea in the South African lowveld

Sclerocarya birrea (A.Rich.) Hochst. subsp. caffra (Sond.) Kokwaro. is a common species throughout the semiarid, deciduous savannas of much of sub-Saharan Africa. It is a favoured species and is frequently maintained in homestead plots and arable fields in an agroforestry situation. Although the abundance and popularity of this species has led to several initiatives to commercialise a number of marula products, the sustainability of the resource base with respect to fruit production has not been considered. This paper reports on a field experiment that monitored growth rates and fruit production of a sample of adult trees from several wild populations. Mean fruit production was 36.8 kg per tree in the first year, and negligible in the second. This was considerably less than previous estimates, which were based largely on small samples or anecdotal reports. The maximum recorded yield was 416.6 kg per tree. Fruit production was positively related to the size of the tree. Growth rates of adult trees were slow. There was a strong positive relationship between mean annual diameter increment and stem diameter. The slow growth rates and low fruit yields indicate that more attention is required regarding the sustainability of there source and its ability to provide sufficient fruit for the growing subsistence and commercial demand at both local and national scales. This revised version was published online in June 2006 with corrections to the Cover Date.     

椰心叶甲在我国潜在分布区的预测分析

椰心叶甲已在我国30个县（市）造成了严重危害,为防止其扩散加剧、有效地开展综合防治工作,利用GARP生态位模型进行潜在分布区预测。结果表明：我国南方较广大的地区适宜椰心叶甲的生存,潜在分布区涉及广东、福建等12省区大部地区和云南等7省区的局部地区;原有受害省区内的潜在分布区远远超过当前的分布区。为明确椰心叶甲向北扩散的可能性,建议尽快开展耐寒性方面的研究。     

山地苹果园穴贮肥水技术研究

为了解决洮南市北部半山区在山地发展苹果树水资源缺乏的矛盾,以洮南市北部半山区果树试验场20年生的123苹果树为试材,研究山地苹果园采用穴贮肥水技术措施对苹果树生长发育的影响。结果表明：穴贮肥水技术可提高新梢生长量21.6%,提高叶绿素含量14.7%;平均单果质量比清耕提高22.3%。特等果率较对照提高27.3%。穴贮肥水可使苹果树增产2161.64 kg.hm-2,纯增收1689.07元.hm-2。     

五种林木果树上的小穴壳菌的病原相关性研究

将从苹果、枣、板栗、杨树、泡桐上分离得到的5株聚生小穴壳菌(Dothiorella gregaria Sacc.)经人工交互接种,形态特征观察及生物学特性、菌丝融合、酯酶同工酶测定,证明该5株小穴壳菌之间有差异,但具有相同的种的遗传物质,在5种寄主上可以相互侵染,认为在种内应存在有专化型。