Aboveground Biomass Production and Nitrogen Content of Gliricidia Sepium under Different Pruning Regime- A Case Study at the Department of Agroforestry Farm (Kwame Nkrumah University of Science and Technology-KNUST)

Gliricidia sepium is considered one of the commonly used multipurpose legume shade trees in Ghana. Different pruning regimes affect the nutrient content as the amount of biomass produced by many multipurpose trees. In this study, the aboveground biomass (both fresh and dry matter) production and nitrogen content in Gliricidia sepium under different pruning regimes (4, 8 and 12 weeks) was studied. The study was carried out in the demonstration farm of Department of Agroforestry in the Faculty of Renewable Natural Resources-KNUST. A total of nine (9) Gliricidia trees were selected. The pruning frequencies were assigned to the selected trees, after an initial pruning of 1.2m from the ground. The data collected include; new fresh weight, dry weight and nitrogen content at the various pruning time. Also, the amount of nitrogen (N) in the new biomass was estimated at each pruning time. The result shows that the aboveground biomass production increased from 4 weeks to 12 weeks regime. Overall nitrogen concentration increased from 2.61% to 3.58% upon reducing the pruning frequency from 4 to 12 weeks, and total nitrogen content was much higher in 12 weeks (36.01g) than in the other pruning frequencies, due to biomass production been larger. In conclusion, the study highlights the potential of Gliricidia biomass as a source of N and green manure for both agricultural and agroforestry purposes. Hence pruning regime of Gliricidia should be considered in managing it for nutrient and manure purposes.

Effect of Nypa fruticans pruning regime and soil properties on regeneration of Mangrove species (Rhizophora racemosa) in Eastern Obolo, Akwa Ibom State

The study was conducted to evaluate the effect of Nypa fruticans pruning regimes on the regeneration of mangrove (Rhizophora racemosa) at Okorombokho in Eastern Obolo, Akwa Ibom State, Nigeria. The Nypa was pruned at a uniform height of 10 cm and the area protected with used fishing nets against infiltration by Nypa seeds in tidal floods. Mangrove plants of similar height were interplanted among pre-existing stands, out of which ten plants were tagged in each sub-plot for the measurement of plant height, leaf area index, and stem girth. Three pruning regimes (0, 4, and 6 weekly pruning (WPR) were adopted and soil samples were collected from 0-15 and 15-30 cm depths. The study was a 3x2 factorial in randomized complete block design with three replications. Soil properties showed consistent differences with depth than with pruning regimes. Bulk density (BD) was statistically similar, averaging 1.04 and 1.06 Mgm-3 in 0-15 and 15-30 cm, respectively, while saturated hydraulic conductivity (Ksat), respectively averaged 0.64 and 0.27 cm h-1 . Electrical conductivity (EC), available phosphorous (Av.P) and base saturation (BS) were significantly (p≤0.05) greater in 4WPR (5.77 dS m-1 ; 30.07 mg g-1 ; 85.4%) than 6WPR (4.54 dS m-1 ; 25.82 mg g1 ; 76.2%) and 0WPR (3.57 dS m-1 ; 23.02 mg g-1 ; 74.3%). Plant height (PH) of mangrove averaged throughout the study was significantly (p≤0.05) greater in 4WPR (80.3 cm) than 0WPR (62.5 cm) but similar to 6WPR (73.4 cm). Stem girth (SG) of mangrove was similar but in the order 4WPR (1.06 cm)>6WPR (0.98 cm)>0WPR(0.86 cm). The pattern of variation in other mangrove growth parameters was similar to plant height and stem girth. The study also showed that PH and SG were negatively correlated with sand, Av.P, and EA but positively correlated with silt and clay, EC, and BS. Results indicated that mangrove species (Rhizophora racemosa) growth was optimum 4WPR than 0WPR and 6WPR and could, therefore, be recommended as a management practice for controlling the growth of Nypa fruticans and regenerating mangrove (Rhizophora racemosa) in the study area.

POST-PRUNING GROWTH OF SOME AFFORESTATION SPECIES IN THE METROPOLITAN REGION OF BELO HORIZONTE, MINAS GERAIS STATE, BRAZIL

ABSTRACT The post-pruning growth of the 16 main species planted in urban afforestation in the Metropolitan Region of Belo Horizonte was evaluated in order to adjust the pruning regime, as well as to evaluate the effect of environmental, management, and tree factors on shoot development. Six individuals were selected per species, and the monthly growth of the five largest shoots at the pruned points was monitored to create two scenarios, considering the median and third quartile of the growth data. The grouping analysis of the growth data was carried out, defining groups of pruning regime according to the similarity in the species growth. Correlation and linear regression analyses were also performed for climatic factors, pruning intensity, diameter at breast height (DBH), phytosanitary status, luminosity in the crown, and permeable area in the soil. It was verified that the arboreal species studied presented a differentiated growth response of post-pruning shoots and can be combined into groups of pruning management regimes ranging from 6 to 24 months. Environmental, individual, and management factors can affect tree sprouting.

Growth and yield of maize and cassava cultivars as affected by mycorrhizal inoculation and alley cropping regime

Effect of myeorrhizal inoculation and two pruning regimes in experimental alley cropping treatments on the leaf biomass and nutrient yield of sole and mixed Gliricidica septum (a Modulating plant) ami Senna siamea (a non-nodulating plant) were investigated both in the greenhouse and in the field. The impact of the mixtures of these legumes as hedgerows on maize and one cultivar of cassava was also studied on the Held. Gliricidia sepiuni prunnings were found to have high nutrient yields, notably 358.4 kg ha-1 of N and 14.7 kg ha-1 of P as well as fast decomposition and nutrient release. In both Giricidia and Senna. there was similar leaf dry matter values in sole and mixed inoculated or non-inoculated trees for either of the pruning regime and for most of the pruning harvests, although significant differences occurred between inoculated and non-inoculated mixed or sole trees. There was no difference between the total leaf dry matter of the two- and three-month pruning regimes in G. sepium. However, in contrast to G. sepium, the total leaf dry matter of the two-month pruning regime of iS'. sianica was lower than its three-month pruning regime, except for sole non-inoculated trees. Generally, inoculation and mixing of trees in the same hedgerows significantly increased the total N and P yield in G. sepium and S. siantea with greater values in the former than the latter. In G. sephium and except for mixed inoculated trees, while total N yield in the leaf was higher in three-monthly primed than two-monthly pruned trees, the converse was the case for P. For S. siamea the total N and P yield were higher in three-monthly than two-monthly pruned trees. Myeorrhizal inoculations consistently increased the yield of the cassava root tuber and maize grain over their non-inoculated counterparts.

788 PB 024 RELATIONSHIP BETWEEN WINTER BUD CONSTRUCTION ANDFLOWER AND FRUIT NUMBER IN `CONCORD' AND `NIAGARA' GRAPEVINES

Winter buds of `Concord' and `Niagara' grapevines were dissected and their embryonic clusters scored to developmental stage. Stage was regressed against flower and fruit number per cluster the following year to see if flowering or fruiting potential could be gauged from bud morphology. `Concord' vines were either minimal-pruned (MP) or balance-pruned (BP) and non-irrigated or provided supplemental irrigation. `Niagara' vines were BP vines which were non-irrigated, irrigated, or nitrogen fertigated. Winter buds of MP `Concord' were significantly less developed than buds of BP vines, and flower and fruit number per cluster also significantly less. Irrigation did not affect bud construction or flower or fruit number per cluster in either pruning regime. Winter buds of `Niagara' had similar cluster stages in all treatments and there were similar flower and fruit number per cluster the following season. Within cultivar and year, there was a positive linear relationship between mean flower number or fruit number per cluster and mean stage of cluster differentiation within buds the previous dormant period. In `Concord', a given winter cluster stage allowed production of significantly more flowers and fruit in 1992 than it did in 1993. A bud's flowering potential thus varies from year to year and depends on factors not solely related to bud morphology.

Alley cropping as a sustainable agricultural technology for the hillsides of Haiti: Experience of an agroforestry outreach project

Alley cropping is a form of hedgerow intercropping where fast-growing leguminous trees are planted at dense within-row spacing, with agricultural crops planted between the hedgerows. This agroforestry technology, with the hedgerows planted on the contour across the slope, appears promising for small farmers on the hittslopes of Haiti An agroforestry outreach project operating in Haiti since 1981 has helped thousands of farmers plant hedgerows on their farms. The farmers are increasingly accepting the technology: the length of hedgerows planted by the farmers in the project area increased from 11 lineal km in 1987 to 140 lineal km in 1988. An evaluation of 50 farms where hedgerows had been installed shows that this technology results in soil conservation and microsite enrichment between hedgerows; the hedgerows also provide fodder and fuelwood. However, refinements are needed in technical aspects of hedgerow management, such as planting configurations, pruning regime, and choice of species. Moreover, soil and plant parameters as well as socioeconomic characteristics must be monitored in a systematic way in order to assess the impact of hedgerow intercropping on the sustainability of Haitian farming systems.