scholarly journals Assessment of Eucalyptus Globulus Coppice Yield in the Highland Areas of North Shewa, Ethiopia

2020 ◽  
Vol 7 (1) ◽  
pp. XX-XX
Author(s):  
Lemma Habteyohannes Woldeamanual ◽  
Getabalew Teshome Reta ◽  
Melese Bekele Nigussie ◽  
Reta Eshetu Tsedeke ◽  
Hailemariam Fiseha Zenebe ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Early Stage ◽  
Woody Species ◽  
High Yield ◽  
Annual Increment ◽  
Coppice Management ◽  
Stem Quality ◽  
Yield Difference ◽  
Stump Diameter ◽  
Number Of Shoots

One of the old traditional methods of silvicultural management is coppicing. Many woody species produce new shoots successfully after coppicing. Regeneration of forest through coppice can be used for short rotation of tree to produce wood biomass for construction and fuel purposes. There are different levels of coppice practiced in Eucalyptus globulus plantation in the highland areas of North Shewa. However, there was no evidence or study which coppice levels can give high yield. Therefore, the objective of this study was to compare yield of E. globulus at different coppice level in the highland areas of North Shewa, Ethiopia. Fifty sampled plots were purposively selected for this study. Volume, mean annual increment, stump height and diameter, stem number and harvesting age were determined from sampled plots. The results revealed that there was no yield difference (p> 0.05) between zero, first, second and third coppice levels. However, stump diameter and number of shoots per stump, stump height were significantly different among 1, 2, 3 coppice levels (p<0.05). Number of shoots were positively correlated with stump diameter and height (r = 0.77, r = 0.72) respectively. Farmers mostly coppice E.globulus from November to December and from April to June. Although statistically there was no yield difference between coppice levels, as farmers described the first coppice has higher yield than other coppice levels. The numbers of shoots per stump were higher in the second and third coppice and this could affect stem quality especially at early stage. Altogether the mean number of stems per hectare was 10812 which is higher than previous studies. Therefore, early silvicultural activities like thinning, early coppice management and pruning has to be done to increase wood stem quality and to promote growth as well.  

scholarly journals Assessment of Eucalyptus Globulus Coppice Yield in the Highland Areas of North Shewa, Ethiopia

2020 ◽  
Vol 7 (2) ◽  
pp. 93-100
Author(s):  
Lemma Habteyohannes Woldeamanual ◽  
Getabalew Teshome Reta ◽  
Melese Bekele Nigussie ◽  
Reta Eshetu Tsedeke ◽  
Hailemariam Fiseha Zenebe ◽  
...  
Keyword(s):  
Eucalyptus Globulus ◽  
Early Stage ◽  
Woody Species ◽  
High Yield ◽  
Annual Increment ◽  
Coppice Management ◽  
Stem Quality ◽  
Yield Difference ◽  
Stump Diameter ◽  
Number Of Shoots

One of the old traditional methods of silvicultural management is coppicing. Many woody species produce new shoots successfully after coppicing. Regeneration of forest through coppice can be used for short rotation of tree to produce wood biomass for construction and fuel purposes. There are different levels of coppice practiced in Eucalyptus globulus plantation in the highland areas of North Shewa. However, there was no evidence or study which coppice levels can give high yield. Therefore, the objective of this study was to compare yield of E. globulus at different coppice level in the highland areas of North Shewa, Ethiopia. Fifty sampled plots were purposively selected for this study. Volume, mean annual increment, stump height and diameter, stem number and harvesting age were determined from sampled plots. The results revealed that there was no yield difference (p> 0.05) between zero, first, second and third coppice levels. However, stump diameter and number of shoots per stump, stump height were significantly different among 1, 2, 3 coppice levels (p<0.05). Number of shoots were positively correlated with stump diameter and height (r = 0.77, r = 0.72) respectively. Farmers mostly coppice E.globulus from November to December and from April to June. Although statistically there was no yield difference between coppice levels, as farmers described the first coppice has higher yield than other coppice levels. The numbers of shoots per stump were higher in the second and third coppice and this could affect stem quality especially at early stage. Altogether the mean number of stems per hectare was 10812 which is higher than previous studies. Therefore, early silvicultural activities like thinning, early coppice management and pruning has to be done to increase wood stem quality and to promote growth as well.  

scholarly journals Combining High Yields and Blast Resistance in Rice (Oryza spp.): A Screening under Upland and Lowland Conditions in Benin

2018 ◽  
Vol 10 (7) ◽  
pp. 2500 ◽  
Author(s):  
Octaviano Yelome ◽  
Kris Audenaert ◽  
Sofie Landschoot ◽  
Alexandre Dansi ◽  
Wouter Vanhove ◽  
...  
Keyword(s):  
Early Stage ◽  
Blast Resistance ◽  
Phenotypic Variability ◽  
Screening Method ◽  
Principal Component ◽  
Yield Potential ◽  
High Yield ◽  
Cycle Duration ◽  
Early Screening ◽  
High Yield Potential

The future security of the supply of rice for food in Africa depends on improving the level of local production to achieve self-sufficiency. In order to cope with the existing gap between production and actual demand, combining a high level of rice blast tolerance and a high-yield potential is necessary. The current study was conducted under upland and lowland conditions in Benin to gain insight into the performance of selected blast-resistant accessions along with some currently grown varieties. This study revealed a high phenotypic variability among these accessions. Furthermore, differences in the performance of these accessions under lowland and upland conditions were observed. Principal component analysis showed their grouping in three clusters. The analysis also demonstrated a high yield potential among the blast-resistant rice accessions whether they were Oryza sativa or O. glaberrima. Furthermore, there was a significant correlation between yield and both spikelet fertility and growth cycle duration. In conclusion, the present study identified promising rice accessions for future breeding. High phenotypic variability in combination with interesting traits can help to develop new resilient varieties. Finally, when the traits correlate with yield, they can be used as markers for an early screening method for identifying promising accessions at an early stage.

Sitka spruce silviculture in Scottish forests

1987 ◽  
Vol 93 (1-2) ◽  
pp. 93-106
Author(s):  
Alan J. Low
Keyword(s):  
Wood Properties ◽  
Sitka Spruce ◽  
Control Measures ◽  
Yield Potential ◽  
High Yield ◽  
Late Winter ◽  
Important Species ◽  
Wide Range ◽  
Stem Quality ◽  
Fertiliser Application

SynopsisSitka spruce is the most important species grown in Scottish forests thanks to its high yield potential, site tolerance and wood properties. It is easily raised from seed or cuttings, and can be readily established and tended under a wide range of site conditions using uncomplicated silvicultural techniques. Spaced furrow ploughing and site drainage are normally required for afforestation; and cultivation may also be desirable prior to restocking. Planting at 2500 trees/ha is done in late winter and spring. Weed control may be necessary, particularly to prevent Calluna-induced growth check. On poor sites, repeated fertiliser application prior to canopy closure can be essential to ensure satisfactory growth, and use of nursing mixtures may be worthwhile. Wherever possible, pole stage crops are thinned regularly to enhance stem quality and diameter growth, but on high windthrow hazard sites the onset of windthrow can be delayed by leaving crops unthinned. After an economic rotation of forty-five to sixty years, crops are clear felled and replanted. During establishment, deer control measures are often required to prevent browsing damage. Damage by insects and fungi is seldom serious, provided that bark-feeding insects are controlled by insecticide at time of replanting, and development of fungal butt rot is minimised by urea treatment of fresh stumps.

scholarly journals Esubacute acidosis in rumen of high-yield dairy cows: Prevalence and prevention

2008 ◽  
Vol 62 (1-2) ◽  
pp. 43-51
Author(s):  
Branko Petrujkic ◽  
Horea Samanc ◽  
Milan Adamovic ◽  
Danijela Kirovski ◽  
Ivan Vujanac ◽  
...  
Keyword(s):  
Ph Value ◽  
Early Stage ◽  
Rumen Content ◽  
High Yield ◽  
Control Group ◽  
Buffer Effect ◽  
Stage Of Lactation ◽  
Rumen Ph ◽  
Rumen Acidosis ◽  
Experimental Group

The objective of the investigations presented in this paper was to establish the frequency of the incidence of subacute acidosis in the rumen of cows (SARA) in the first three months of lactation and the possibilities for its prevention using a mineral mix based on bentonite, zeolite, magnesium oxide, and sodium bicarbonate (Mix plus). The values obtained for the rumen pH content show that subacute rumen acidosis occurs in in 20 percent of the examined cows in the early stage of lactation. For these investigations, cows in early stages of lactation were chosen and divided into 2 groups. Cows of the experimental group were administered a fodder mix which contained the mineral mix for a buffer effect (Mix plus). The average values of the rumen pH content in the control and the experimental group of cows at the beginning and on the 30th day of the experiment were approximately the same and did not differ significantly (p>0.05). On the 60th day of the experiment, the values for the electrochemical reaction of the rumen content for the control group amounted to an average of 6.219?0.18, and for the experimental group of cows it was 6.772?0.23. The obtained difference was statistically very significant (p<0.001). At the end of the experiment, on the 90th day, the average pH value of the rumen content of cows of the control group was 6.308?0.16, while this value in the experimental group of cows was significantly higher and amounted to 6.676?0.29 (p<0.01).

The development, penetrance, and seed vigour of multi-ovary wheat and its application in hybrid breeding

2019 ◽  
Vol 70 (9) ◽  
pp. 781 ◽  
Author(s):  
Jialin Guo ◽  
Gaisheng Zhang ◽  
Yulong Song ◽  
Shoucai Ma ◽  
Na Niu ◽  
...  
Keyword(s):  
Floral Development ◽  
Theoretical Foundation ◽  
Developmental Process ◽  
Early Stage ◽  
Wheat Breeding ◽  
Hybrid Breeding ◽  
High Yield ◽  
Practical Application ◽  
Seed Vigour ◽  
Germination Ability

Multi-ovary wheat is a unique variety of wheat that has one to three pistils and three stamens, and can stably set one to three grains in each floret. By observing the developmental process of additional pistils, we found that the additional pistil was derived from a protrusion generated at the base of the main pistil, between the frontal stamen and lateral stamen. The additional pistil’s development was greatly delayed compared with the main pistil at an early stage. However, after the awn exposed stage, it developed very rapidly to a mature pistil within the maturity time of the main pistil. Generally, the grains originating from additional pistils were smaller than the grains from the main pistil. By studying the penetrance and germination conditions of multi-ovary wheat, we found that no matter which ovary the grains originated from, they had the same penetrance. However, the germination ability of grains generated from the main pistil was significantly higher than that of grains from additional pistils. Our results showed that multi-ovary wheat was an excellent variety, not only for studying the mechanisms of the multi-ovary trait and floral development in wheat, but also for improving the propagation coefficient and promoting the progress of wheat breeding. This paper lays a theoretical foundation for the practical application of multi-ovary trait in hybrid wheat; our results could be implemented in fostering future breeding activities focussed on the development of high yield wheat cultivars.

The effect of catena position and stump characteristics on the coppice response of three savannah fuelwood species

2005 ◽  
Vol 32 (1) ◽  
pp. 76-84 ◽  
Author(s):  
S.A. KASCHULA ◽  
W.C. TWINE ◽  
M.C. SCHOLES
Keyword(s):  
Resource Allocation ◽  
Basal Area ◽  
Area Ratio ◽  
Growth Patterns ◽  
Allocation Of Resources ◽  
Important Species ◽  
Harvesting Technique ◽  
Stump Diameter ◽  
Allocation Strategies ◽  
Number Of Shoots

Fuelwood is still the primary energy source for rural households across the savannah biome of Africa. Coppice growth is an important species-specific trait that strongly influences fuelwood production and regeneration, and yet coppice growth patterns are poorly understood in African savannahs. It is therefore vital that factors affecting coppice growth of species, such as environment conditions and harvesting technique, be better understood in order to develop models for sustainable fuelwood use. This study investigated coppice growth and resource allocation strategies in relation to (1) position along the landscape catena and (2) harvesting technique, for three savannah fuelwood tree species: Dichrostachys cinerea, Albizia harveyi and Combretum collinum. The study was conducted in a dystrophic semi-arid savannah in the far north-east of South Africa. A total of 1146 harvested stumps were sampled in topland and bottomland sites in three locations around a rural village. Stump characteristics (diameter and height) and coppice shoot variables (number of shoots, length and diameter of each shoot, length of longest shoot, and diameter of fattest shoot) were measured for each stump. Three soil samples were taken in each site for physical and chemical analysis. No statistically significant differences were found in soil variables between topland and bottomland sites, probably due to low sample size. Coppice resource allocation strategies varied between species. D. cinerea exhibited a ‘quantity-driven’ strategy, with the production of large numbers of relatively small coppice shoots with high length:diameter ratio (shoot taper function). C. collinum exhibited a ‘quality-driven’ strategy, characterized by the production of a relatively low number of larger coppice shoots. Coppice growth variables for A. harveyi were intermediate between those of the other two species, suggesting a strategy where allocation of resources to the number and growth of shoots is more balanced. However, allocation of resources relative to the size of the cut stem, indexed by total shoot basal area:stump basal area ratio, did not differ significantly between species. Coppice growth was strongly favoured in bottomland sites for D. cinerea, and to a lesser degree, C. collinum. Catenal position had a negligible influence on coppice growth of A. harveyi. Number of shoots produced increased with cutting height for all three species. For all three species the number of shoots increased with stump diameter, and mean shoot size also increased with stump size for D. cinerea. There was a significant negative relationship between stump diameter and total shoot basal area:stump basal area ratio for A. harveyi and C. collinum. A framework for optimizing different coppice growth variables according to species, catenal position and harvesting technique is given.

scholarly journals Analysis of Genotype-Interaction of a 4-Year-Old Populus euramericana Using BLUP-GGE Technique

2021 ◽  
Author(s):  
Ning Liu ◽  
Changjun Ding ◽  
Bo Li ◽  
Mi Ding ◽  
Xiaohua Su ◽  
...  
Keyword(s):  
Goodness Of Fit ◽  
Technical Assistance ◽  
Early Stage ◽  
Tree Height ◽  
Practical Experience ◽  
High Yield ◽  
Mixed Effect ◽  
Populus Euramericana ◽  
Main Research ◽  
Genotype Effect

Poplar is a globalized commercial tree species that supports humanity's economy, energy, and ecology. To evaluate the twelve hybrid Populus euramericana genotypes developed in China, a total of six locations were selected for the test, comprising four climatic types and three soil kinds. The objective of this study is to characterize the early stages of Populus euramericana growth and test locations; to identify good genotypes for stable and high yield that may be encouraged; and to offer practical experience and technical assistance for further breeding of Populus euramericana. Main research methods include the statistical description of tree heights and diameter at breast heights[DBH], the establishment of a mixed effect model to analyze the genotype and environmental interaction effect [G&times;E], the use of best linear unbiased prediction[BLUP] values as GGE biplots to achieve visual screening, and the calculation of genetic parameters. Results show that the genotype effect [G], the environmental effect [E], and the G&times;E is significant; the BLUP value has a strong correspondence with the observed value; the goodness of fit of all biplots can explain more than 85% of the variation; broad-sense heritability of tree height and DBH is 0.13 and 0.3, type-B correlation is 0.36 and 0.65; G5, G7, G4 and G9 are excellent genotypes with high yield and stability; using these four genotypes tree height and DBH can get 3.35% and 0.81% genetic gains.The study concludes as follows: Rank-change interaction and scale-effect interaction were distinctly occurred. The G, E, and G&times;E all had a significant effect on the growth of poplar trees during their early stage. G4, G5, G7, and G9 genotypes have favorable development characteristics. N146 is a great source of paternal genetics.

scholarly journals Redeployment of Shoots into Better-Lit Positions within the Crowns of Saplings of Five Species with Different Growth Patterns

Forests ◽  
2020 ◽  
Vol 11 (12) ◽  
pp. 1301 ◽  
Author(s):  
Kohei Koyama ◽  
Hiroyuki Shirakawa ◽  
Kihachiro Kikuzawa
Keyword(s):  
Early Stage ◽  
Woody Species ◽  
Growth Period ◽  
Growth Patterns ◽  
Light Environment ◽  
Tree Crown ◽  
Quantitative Evidence ◽  
Fast Growing ◽  
Slow Growing ◽  
Fast Growing Species

Research Highlights: We demonstrate the first quantitative evidence that the shoot shedding of fast-growing species growing in a high-light environment is part of the process of shoot redeployment into better-lit outer parts of the crown. Background and Objectives: Light foraging by redeploying organs from shaded regions of a tree crown into better-lit regions is considered to apply to both leaves and shoots. To date, however, this hypothesis has never been tested for shoots. Materials and Methods: We investigated the shoot dynamics of saplings of five deciduous woody species. We included fast-growing and slow-growing species (Alnus sieboldiana Matsum., Castanea crenata Siebold & Zucc., Betula ermanii Cham., Acer distylum Siebold & Zucc., and Fagus crenata Blume). Results: Shoots in the shaded regions of the crowns of the fast-growing trees showed higher mortality rates than those at better-lit positions. Because of the selective shedding of the shaded shoots, at the end of the growth period the light environment experienced by the shoots that survived until the following spring was similar to that at the early stage of the same growth period. By contrast, the slow-growing trees displayed slow and determinate growth, with a very low mortality rate of shoots at all positions in the crown. Conclusions: The rapid shoot turnover of the fast-growing species resulted in the redeployment of shoots into better-lit positions within the tree crown in a manner similar to the redeployment of leaves.

The influence of irrigation and fertilization on heartwood and sapwood contents in 18-year-old Eucalyptus globulus trees

2006 ◽  
Vol 36 (10) ◽  
pp. 2675-2683 ◽  
Author(s):  
Isabel Miranda ◽  
Jorge Gominho ◽  
Ana Lourenço ◽  
Helena Pereira
Keyword(s):  
Tree Growth ◽  
Eucalyptus Globulus ◽  
Growth Conditions ◽  
Raw Material ◽  
Pulp Yield ◽  
Stem Quality ◽  
Total Tree

The quality of wood from 18-year-old Tasmanian bluegum (Eucalyptus globulus Labill.) trees was assessed in relation to heartwood content, accumulation of extractives, and pulp yield using two growth conditions: control (C) and growth optimized by irrigation and fertilization in the first 6 years of growth (IL). Within the tree, heartwood content decreased from the base upwards, representing, on average, 77.7% and 67.6% at the base and 7.0% and 4.8% at 29.3 m height for IL and C trees, respectively. Heartwood volume represented 65.6% and 55.6% of total tree volume for IL and C trees, respectively. Heartwood content was positively correlated with tree growth, while sapwood content remained rather constant, with a radial width of approximately 2 cm. Heartwood contained more extractives than sapwood (5.3% vs. 4.0%) and pulp yield was lower from heartwood than from sapwood (58.0% vs. 56.0%). Pulp yield was negatively correlated with content of extractives. No difference in extractives or pulp yield was found between IL and C trees. The presence of heartwood decreases the quality of raw material for pulping and should be regarded as a stem-quality variable in eucalypt forestry.

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