This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications mini...This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.展开更多
Interbreeding of Clarias gariepinus and Heterobranchus bidorsalis was done to produce F1 with fast growing trait using synthetic ovaprim hormone （0.5 ml/kg）. Mean hatching rates were very high （between 72.5% and 92...Interbreeding of Clarias gariepinus and Heterobranchus bidorsalis was done to produce F1 with fast growing trait using synthetic ovaprim hormone （0.5 ml/kg）. Mean hatching rates were very high （between 72.5% and 92.5%）. The parental stock of C. gariepinus showed higher survival value of 96.0% under indoor rearing. The hybrid produced by crossing of ♂H. bidorsalis and ♀C. gariepinus showed higher growth rate in hapa under suspended （14. 1 0 g） and non-suspended condition （14.30 g） in earthen pond at the end of four months rearing. The growth rate under suspended and non-suspended condition were very high and were not significant different from each other. Comparatively, the hybrid of the cross between （♀） H. bidorsalis and （♂） C. gariepinus was better than the other cross under non-suspended condition while the parental strain ofH. bidorsalis was to produce under the suspended condition. The purpose of this is to produce improved fish with fast growing trait and other qualitative characters that could meet the economic target of Nigerian aquaculture, The hybrids have potential as commercial food fish.展开更多
文摘This study examines a management strategy for restoring grassland and prairie communities that have become degraded due to high density stands of invasive nitrogen-fixing plants. The novel management applications minimize the use of herbicides and maximize the competitive interactions of native species. The management method includes two seasons of application of organic fertilizer （4-1-4）, an initial herbicide （Pasture Gard, Dow Agro） application, and mowing, where mowing was a necessary treatment to control secondary growth in prairie habitats, to control high density patches of Lespedeza （L.） Cuneata, in a completely randomized factorial experiment. The herbicide was effective in reducing L. Cuneate stem density 0 stems/m^2 from an initial 88 stems/m^2 with cover reduced to 0% from 16%. The fertilizer only treatment reduced L. Cuneata percent cover to 6% from initial cover of 16%, but did not reduce the number of stems. The management strategy is an effective fast step in restoring a native prairie invaded by a nitrogen-fixing plant.
文摘Interbreeding of Clarias gariepinus and Heterobranchus bidorsalis was done to produce F1 with fast growing trait using synthetic ovaprim hormone （0.5 ml/kg）. Mean hatching rates were very high （between 72.5% and 92.5%）. The parental stock of C. gariepinus showed higher survival value of 96.0% under indoor rearing. The hybrid produced by crossing of ♂H. bidorsalis and ♀C. gariepinus showed higher growth rate in hapa under suspended （14. 1 0 g） and non-suspended condition （14.30 g） in earthen pond at the end of four months rearing. The growth rate under suspended and non-suspended condition were very high and were not significant different from each other. Comparatively, the hybrid of the cross between （♀） H. bidorsalis and （♂） C. gariepinus was better than the other cross under non-suspended condition while the parental strain ofH. bidorsalis was to produce under the suspended condition. The purpose of this is to produce improved fish with fast growing trait and other qualitative characters that could meet the economic target of Nigerian aquaculture, The hybrids have potential as commercial food fish.
