Estimation of heritability and genetic gain in height growth in Ceiba pentandra

Ceiba pentandra (L.) has been selected for plantation establishment in Ghana under the National Forest Plantation Development Programme of Ghana (NFPDP). This has led to a rise in demand for its seedlings for large scale commercial plantation establishments with seed of C. pentandra being collected from the wild and used to raise seedlings to meet the demands of the programme. The primary purpose of most of these plantations is timber with height growth as one of the key economic traits. However, there is relatively inefficient information available on the heritability and genetic gain in height growth in C. pentandra based on which selection and subsequent breeding could be made. This poses a major challenge to the production of new cultivars for the forestry industry of Ghana. The current study looked at the estimation of narrow sense heritability (h2) and genetic gain in height growth in C. pentandra using 37 accessions from Ghana. Narrow sense heritability was 0.56 and genetic gain in height ranged from -52.82 to 37.30 cm/yr. Twenty-two (22) accessions (59.46%) had mean height increment above the overall mean performance and were recommended for conservation as seed trees. The results were discussed in relation with the conservation of C. pentandra genetic resources and the potential of accessions for high genetic gains.Key words: Ceiba pentandra, narrow sense heritability, genetic gain, height growth, stem dieback disease

Implications of Charcoal Briquette Produced by Local Communities on Livelihoods and Environment in Nairobi Kenya

The residents of Nairobi, Kenya, use 700 tonnes of charcoal per day, producing about 88 tonnes of charcoal dust that is found in most of the charcoal retailing stalls that is disposed of in water drainage systems or in black garbage heaps. The high costs of cooking fuel results in poor households using unhealthy materials such as plastic waste. Further, poor households are opting to cook foods that take a short time to prepare irrespective of their nutritional value. This article presents experiences with community self-help groups producing charcoal fuel briquettes from charcoal dust in poorer nieghbourhoods of Nairobi for home use and sale. Households that produced charcoal fuel briquettes for own use and those that bought them saved 70% and 30% of money spent on cooking energy respectively. The charcoal fuel briquettes have been found to be environmentally beneficial since they produce less smoke and increase total cooking energy by more than 15%, thereby saving an equivalent volume of trees that would be cut down for charcoal. Charcoal briquette production is a viable opportunity for good quality and affordable cooking fuel. Bioenergy and waste management initiatives should promote recovery of organic by-products for charcoal briquette production

Mycorrhizal Association and its Benefits to Allanblackia parviflora Tree Seedlings in the Nursery

Allanblackia species are high value multipurpose indigenous fruit trees whose seeds contain edible oil that has become a foreign exchange earner for rural-based enterprises. Wild harvesting could not sustain the supply to industry and therefore domestication was focused on developing propagation techniques, selecting and collecting elite planting materials. Little emphasis was placed on the soil nutrient requirements where preliminary results showed seedlings grown in rhizosphere soil of wild trees had good growth performance. A study was undertaken to examine microbial-Allanblackia parviflora plant interactions and determine their benefits to nursery seedlings. Roots of wildlings and rhizosphere soil from A. parviflora trees were collected from three forest reserves and the roots assessed for mycorrhizal colonization. Allanblackia parviflora seedlings were raised in different potting media with different ratios and their height and diameter determined. Soil treatments were also analyzed for nutrient and chemical contents. Vesicles, arbuscular structures, hyphal coils and intercellular hyphae were found on root tips of wildlings collected from rhizosphere soil of Allanblackia (AB) trees and seedlings grown in soil treatments containing AB soil. Root colonization of A. parviflora was largely in the form of extensive cell-to-cell growth of hyphal coils characteristic of Paris-type morphology. Addition of Agricultural field soil (Ferric Acrisol, Afs) or Humus (H)+Afs to AB improved height of seedlings. Seedlings grown in AB soil alone increased best in height with age followed by those grown in combination of 75% AB soil and 25% Afs. Available P was highest in Afs (220.84 mgP/kg) and low in AB soil (6.54 mgP/kg) while combination of H + Afs to AB increased K level to 341.34 mgK/kg. The improvement in growth must be due to both vesicular-arbuscular mycorrhizal fungi and soil chemical content of AB soil

Water application rate and frequency affect seedling survival and growth of Vangueria infausta and Persea americana

Adequate amount of water is critical to successful tree nursery operation among resource-constrained smallholder farmers in Africa. Two  experiments were undertaken with the objectives of evaluating effects of water application rate and frequency on seedling growth and survival of Persea americana and Vangueria infausta. In experiment 1, water was applied to seedlings at 500 ml per 1 L polyethylene bag daily and at two, four and six day intervals. In experiment 2, water was applied to seedlings every two days at the rate of 25, 50, 100 and 150 ml per polyethylene bag. The results indicated that V. infausta was more responsive to the rate than frequency of water application. Water application of 100 ml every two days was effective in promoting seedlings growth and survival for both species. Application of 500 ml of water every two days promoted growth of P. americana, while watering frequency had no significant effect on V. infausta. It is concluded that V. infausta seedlings require less frequent watering. Both species could be successfully raised with 100 ml of water applied every two days.Key words: Nursery irrigation, nutrient reserves, root collar diameter, seedling mortality

The management of tree genetic resources and the livelihoods of rural communities in the tropics: non-timber forest products, smallholder agroforestry practices and tree commodity crops

Products and services provided by trees in forests and farmland support the needs and promote the wellbeing of hundreds of millions of people in the tropics. Value depends on managing both the diversity of tree species present in landscapes and the genetic variation within these species. The benefits from trees and their genetic resources are, however, often not well quantified because trade is frequently outside formal markets, there is a multiplicity of species and ways in which trees are used and managed, and genetic diversity within species is frequently not given proper consideration. We review here what is known about the value of trees to rural communities through considering three production categories: non-timber products harvested from trees in natural and managed forests and woodlands; the various products and services obtained from a wide range of trees planted and/or retained in smallholders’ agroforestry systems; and the commercial products harvested from cultivated tree commodity crops. Where possible, we focus on the role of intra-specific genetic variation in providing support to livelihoods, and for each of the three production categories we also consider wider conservation and sustainability issues, including the linkages between categories in terms of management. Challenges to ‘conventional wisdom’ on tree resource use, value and management – such as in the posited links between commercialisation, cultivation and conservation – are highlighted, and constraints and opportunities to maintain and enhance value are described