Assessment on the effects of potting mixtures on germination and growth of Moringa oleifera (LAM) seedlings in Sudan savanna ecology zone of Nigeria

This study was carried out in the Forestry nursery, Audu Bako College of Agriculture  ambatta, Kano-Nigeria. The aim was to evaluate seed germination and the growth rates of Moringa oleifera (Lam) in three (3) different growth media; to determine the best growth medium to raise Moringa seedlings; and to determine which of the growth medium support vigorous and early growth for Plantation establishment in Sudan savanna ecology of Nigeria. The different soil media were: top soil, river sand and cow dung manure (treatment A); top soil, river sand and poultry manure (treatment B) and top soil and river sand (treatment C). Seeds of M. oleifera(Lam) tested for viability by floatation method were planted in different soil Media and replicated three times. The experiment was arranged in a Completely Randomized Design and watering was carried in all the treatments daily. The germination and growth of the seedlings were assessed for twelve weeks. Parameters measured were: germination rates, seedlings height, leaflets width and length, and leaflet numbers. Data were subjected to ANOVA and results showed that there was significant difference on parameters assessed on the 10th day (F=4.56, P=0.01 P<0.05) and 30th day (F=3.42, P=0.04 P<0.05) among the three treatments in terms of height (cm) but on the 20th day, there was no significant variation (F=1.02, P=0.37 P>0.05) in height of the seedlings among the treatments. Therefore, germination and early growth rate of Moringa oleifera seeds in treatment C (topsoil & river sand) demonstrated better growth potential on the average, than seeds planted in treatment A and B, respectively.Key words: Germination; Moringa oleifera (lam); Treatment; Seedlings; Media/medium; Parameter

Composition and distribution of economic tree species in Nagi Forest Reserve, Benue State, Nigeria

The inventory of economic trees in Nagi Natural Forest Reserve, Benue state was carried out to determine the status and dominance tree species. A total area of 0.4ha was sampled representing twenty percent of the reserve. Ten (10) sample plots of equal size (20 m x 20m) were randomly selected using simple random design. In each plot, all living trees with stem diameter (dbh) ≥10 cm were identified with their botanical names and their diameter at breast heights were all measured. A total number of 84 trees were enumerated on 0.4 ha sample area. The results of the study showed that 19 genera belonging to 15 families were present.Families of Caesalpiniceae, Chrysobalanceae, Euphobiaceae and Leguminosae were dominant with two species each. All other families had only one species each. Based on the results obtained, only three (3) economic tree species out of the 22 protected were found in Nagi forest reserve. These include Prosopis africana, Parkia biglobosa and Khaya senegalensis, with frequencies of 9, 6 and 4, respectively. Prosopis africana recorded the highest mean basal area (0.27m) while Bridelia ferruginea (0.012m) recorded the least basal area. Higher number of stands were recorded in P. africana (9) and the least number of stands were recorded in Daniellia oliverii (2). Also, Prosopis africana was the most dominant while Morinda lucida was the least   dominant. Sustainable management of the protected species should be consider as a priority by Government and individual. This can be achieved through  establishment of plantation of such protected species. This could prevent the imminent loss of  biological diversity that would eventually accompany the exploration.Key Words: Economic, tree, species, dominant, forest reserve

Crown ratio assessment for Prosopis africana (Guill. and Perr.) Taub species in Makurdi, Nigeria

Information on tree crown is prerequisite for sustainable utilization of forest tree resources, as it is the site for physiological activities that lead to tree growth and development. Crown ratio (CR) is an index of tree stability; it indicates tree vigour and is a useful parameter for assessing forest condition. This study aimed at assessing crown ratio for improved silvicultural management of naturally grown Prosopis africana species within the University of Agriculture Makurdi, Nigeria. Nine temporary sample plots (TSPs) of size 100 m x 100 m were established using simple random sampling method. Diameter at breast height (Dbh), total height (Ht) and crown diameter (Cd) and height to live crown base (HCB) were measured for all living P. africana trees with Dbh > 10 cm within the 9 TSPs. Data collected were subjected to descriptive and bivariate correlation analysis. The trees were further classified based on their Crown ratio as high vigour (CR>0.50), moderate vigour (CR= 0.30-0.50) and low vigour (CR<0.30). The result revealed that CR had strong negative correlation with Ht and HCB. Tree diameter attributes showed low positive correlation with CR. However, about 69% of the trees are within moderate CR class and only 3% areof the low CRclass. This implies that majority of the P. africana species in the study area are of moderate and high vigour. Hence, appropriate silvicultural Treatment such as thinning is recommended for trees with CR <0.3 to ensure moderate, better stand stability and sustainability of the species benefits.Keywords: Correlation; Crown ratio; Economic trees; Tree growth characteristics; Prosopis african

Crown-Stump Diameter Model for Parkia biglobosa Benth. Species in Makurdi, Benue State, Nigeria

The crown of tree is the centre of physiological activity which gives an indication of the potential photosynthetic capacity on a tree. Though, its measurement remains a challenge in forest inventory task. The ability to predict crown diameter from stump diameter provides an effective technique of obtaining its estimate. This helps in detecting the excessive tree felling than actual requirements and wildlife suitability.The main objective of this study was to develop and test crown diameter prediction models for silvicultural management of naturally grown Parkia biglobosa within the University of Agriculture, Makurdi. Nine 100 m x 100 m temporary sample plots were established using simple random sampling method. Crown diameter and stump diameter were measured in all living P. biglobosa trees with stump diameter ≥10.0 cm. Least square method was used to convert the counted stumps into harvested crown dimension. Three linear and three non-linear models using stump diameter as the exploratory variable were developed and evaluated using the adjusted coefficient of determination (Adj.R2), standard error of estimate (SEE), prediction error sum of squares (PRESS) and Akaike information criterion (AIC). The crown-stump diameter relationship was best described by the double logarithmic function with .The result showed that Crown diameter estimation was feasible even when the only information available is stump diameter.The resulting equation was tested for validation with independent data obtained from additional plots and was found to be desirable for estimating the crown diameter for Parkia biglobosa in Makurdi, Benue State, Nigeria

Low Q^2 Jet Production at HERA and Virtual Photon Structure

The transition between photoproduction and deep-inelastic scattering is investigated in jet production at the HERA ep collider, using data collected by the H1 experiment. Measurements of the differential inclusive jet cross-sections dsigep/dEt* and dsigmep/deta*, where Et* and eta* are the transverse energy and the pseudorapidity of the jets in the virtual photon-proton centre of mass frame, are presented for 0 < Q2 < 49 GeV2 and 0.3 < y < 0.6. The interpretation of the results in terms of the structure of the virtual photon is discussed. The data are best described by QCD calculations which include a partonic structure of the virtual photon that evolves with Q2.Comment: 20 pages, 5 Figure

Hadron Production in Diffractive Deep-Inelastic Scattering

Characteristics of hadron production in diffractive deep-inelastic positron-proton scattering are studied using data collected in 1994 by the H1 experiment at HERA. The following distributions are measured in the centre-of-mass frame of the photon dissociation system: the hadronic energy flow, the Feynman-x (x_F) variable for charged particles, the squared transverse momentum of charged particles (p_T^{*2}), and the mean p_T^{*2} as a function of x_F. These distributions are compared with results in the gamma^* p centre-of-mass frame from inclusive deep-inelastic scattering in the fixed-target experiment EMC, and also with the predictions of several Monte Carlo calculations. The data are consistent with a picture in which the partonic structure of the diffractive exchange is dominated at low Q^2 by hard gluons.Comment: 16 pages, 6 figures, submitted to Phys. Lett.

Energy Flow in the Hadronic Final State of Diffractive and Non-Diffractive Deep-Inelastic Scattering at HERA

An investigation of the hadronic final state in diffractive and non--diffractive deep--inelastic electron--proton scattering at HERA is presented, where diffractive data are selected experimentally by demanding a large gap in pseudo --rapidity around the proton remnant direction. The transverse energy flow in the hadronic final state is evaluated using a set of estimators which quantify topological properties. Using available Monte Carlo QCD calculations, it is demonstrated that the final state in diffractive DIS exhibits the features expected if the interaction is interpreted as the scattering of an electron off a current quark with associated effects of perturbative QCD. A model in which deep--inelastic diffraction is taken to be the exchange of a pomeron with partonic structure is found to reproduce the measurements well. Models for deep--inelastic $ep$ scattering, in which a sizeable diffractive contribution is present because of non--perturbative effects in the production of the hadronic final state, reproduce the general tendencies of the data but in all give a worse description.Comment: 22 pages, latex, 6 Figures appended as uuencoded fil

A Search for Selectrons and Squarks at HERA

Data from electron-proton collisions at a center-of-mass energy of 300 GeV are used for a search for selectrons and squarks within the framework of the minimal supersymmetric model. The decays of selectrons and squarks into the lightest supersymmetric particle lead to final states with an electron and hadrons accompanied by large missing energy and transverse momentum. No signal is found and new bounds on the existence of these particles are derived. At 95% confidence level the excluded region extends to 65 GeV for selectron and squark masses, and to 40 GeV for the mass of the lightest supersymmetric particle.Comment: 13 pages, latex, 6 Figure

Measurement of D* Meson Cross Sections at HERA and Determination of the Gluon Density in the Proton using NLO QCD

With the H1 detector at the ep collider HERA, D* meson production cross sections have been measured in deep inelastic scattering with four-momentum transfers Q^2>2 GeV2 and in photoproduction at energies around W(gamma p)~ 88 GeV and 194 GeV. Next-to-Leading Order QCD calculations are found to describe the differential cross sections within theoretical and experimental uncertainties. Using these calculations, the NLO gluon momentum distribution in the proton, x_g g(x_g), has been extracted in the momentum fraction range 7.5x10^{-4}< x_g <4x10^{-2} at average scales mu^2 =25 to 50 GeV2. The gluon momentum fraction x_g has been obtained from the measured kinematics of the scattered electron and the D* meson in the final state. The results compare well with the gluon distribution obtained from the analysis of scaling violations of the proton structure function F_2.Comment: 27 pages, 9 figures, 2 tables, submitted to Nucl. Phys.

Measurement of Leading Proton and Neutron Production in Deep Inelastic Scattering at HERA

Deep--inelastic scattering events with a leading baryon have been detected by the H1 experiment at HERA using a forward proton spectrometer and a forward neutron calorimeter. Semi--inclusive cross sections have been measured in the kinematic region 2 <= Q^2 <= 50 GeV^2, 6.10^-5 <= x <= 6.10^-3 and baryon p_T <= MeV, for events with a final state proton with energy 580 <= E' <= 740 GeV, or a neutron with energy E' >= 160 GeV. The measurements are used to test production models and factorization hypotheses. A Regge model of leading baryon production which consists of pion, pomeron and secondary reggeon exchanges gives an acceptable description of both semi-inclusive cross sections in the region 0.7 <= E'/E_p <= 0.9, where E_p is the proton beam energy. The leading neutron data are used to estimate for the first time the structure function of the pion at small Bjorken--x.Comment: 30 pages, 9 figures, 2 tables, submitted to Eur. Phys.