Postdoctoral fellow and Teaching Instructor Mixedwood Ecology and Management Program, University of Northern British Columbia, Prince George, BC V2N 4Z9, Canada
Abstract: In Europe, the English yew species (Taxus baccata L.) is endangered. Intensive human land-use, including forest management, has caused a decrease of the yew populations all over Europe. In Austria, gene conservation forests are used for the in situ conservation of populations of this rare tree species by silvicultural treatments. In order to improve the conservation management in these gene conservation forests, this study addresses the relation between competition and viability of yew populations through the use of structural diversity indices. The structural indices, which include mingling, tree–tree distance, diameter, and tree height differentiation, were determined for a structural group of four trees as well as the neighbouring trees of the male and female yews at the monitoring plots on a regular grid in three gene conservation forests. Although the three study sites provided quite different environmental conditions for English yew, the vitality of each individual yew was influenced by the interspecific competition of the neighbouring tree species at all sites. Low vitality was associated with a small mean distance to neighbours and large tree height differentiation. In conclusion, we suggest that a combination of different structural indicators is needed for an integrative assessment of conservation status in the gene conservation forests. This would help improve the evaluation of the impact management has on yew population viability
Abstract: Population viability risk management (PVRM) provides a framework for explicitly including qualitative information about the possible outcomes of a management decision with regard to the viability of an endangered population in conservation management. Multi-criteria decision-making (MCDM) techniques enables managers to select the most preferred choice of action in a context where several criteria apply simultaneously. In that context a combined approach of the PVRM concept and a MCDM technique is presented for the development, evaluation and finally ranking of the in situ conservation strategies. We discuss the concept based on a case study for the maintenance of a gene conservation forest of an English yew population (Taxus baccata L.) in Styria, Austria. As part of the PVRM the analytic hierarchy process (AHP) is used to evaluate six conservation strategies with regard to the viability of the yew population. The viability of the population is evaluated based on the results of an analysis of the current environmental, social and economical state and a characterization of the ecological parameters of its population. The most significant risk factors (illegal cutting, browsing by game, tree competition, light availability and genetic sustainability) are structured and prioritised according to their impact on the viability of the yew population applying the AHP. Effects of the six conservation strategies on the viability of the yew population are determined through a qualitative assessment of the probability of a decrease of the population along with four different environmental scenarios. In this context strategy IV combining selective thinning, protection measures, game control with public relation activities seems to be the most effective alternative. The benefits of the combined approach of the PVRM concept with the AHP for the rational analysis of conservation strategies for this endangered tree species are discussed
Abstract: English yew Taxus baccata L. has been catalogued as endangered tree species and prone to extinction in Austria as well as many other parts of Europe. The present work is based on the comparison of the natural population of two gene conservation forests from different geographic locations in Austria where the spatial structure, regeneration status and possible conservation measures are examined. The pole stand distribution varied distinctly in each sites. The total no of individuals per ha (DBH ≥5 cm), average DBH and average height were 492 n·hm-2, 8.8 cm and 6.3 m in Stiwollgraben whereas in Leininger Riese 45 n·hm-2, 16.3 cm and 7.6 m respectively. Over 79% of the Stiwollgraben population were represented the good health condition, while in Leininger Riese it was less then 49 % which means population of Stiwollgraben is in better condition compared to Leininger Riese. The sites differed considerably in the pattern of regeneration but pattern were consistent with the dynamics depicted by the age distribution. Considering the one-year-old seedlings Stiwollgraben contains 13 019 individuals·hm-2 whereas Leininger Riese only 1 368. Surprisingly there were no any saplings in respect of 51 to 150 cm height classes in both sites and 30 to 50 cm in Stiwollgraben. In that context the conservation of English yew on the forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.
Abstract: English yew (Taxus baccata L.) is a rare tree species in Austria and gene conservation forests reserves
are used to maintain English yew populations by silvicultural treatments. This paper describes the current
situation of an English yew population at “Stiwollgraben”in Austria with regard to stand structure, vitality
and natural regeneration. The area is one of the most important sites in Austria as it consists of 2236 yews.
The vitality condition of the yew is very good, and more than 79% of the yews have been assessed as very vital
to vital. The potentiality for natural regeneration (13019 one-year seedlings ha–1) is very high, but not all
height classes are represented. This indicates a high survival ability of English yew at this site. Three different
treatment strategies are described to maintain the yew population. The future effects of these treatments are
discussed in the light of the environmental requirements of English yew.
Abstract: An experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh from July to December 2002 to study the effect of number of seedlings/hill and level of nitrogen from different sources on the performance of transplant aman rice (BRRI dhan 32) under SRI method. The experiment was laid out in a randomized complete block design with four replications. The treatment used in the experiment consisted of a) number of seedlings / hill i) one seedling/hill 2) two seedlings/hill and b) level of nitrogen from different sources i) BRRI recommended dose of prilled ures (150 kg/ha) ii) 25% above BRRI recommended dose of prilled urea (187.5 kg/ha) iii) BRRI recommended dose of urea super granules (1 granule /4 hill) vi) 25% above USG (1.25 granules/4 hill) and v) compost (20 t/ha). Effect of number of seedlings/hill was significant in respect of all the yield attributes and growth characters except panical length, number of total spikletes /panicle and 1000-grain weight. Significantly higher grain yield (6.68 t /ha) was obtained from 1 seedlings/hill. Level of Nitrogen from different sources significantly influenced all the growth characters and yield attributes. The highest grain yield (7.11 t /ha) was obtained from BRRI recommended dose of urea super granules. The interaction effect of number of seedlings/hill and level of nitrogen from different sources did not exert any significant influnces on yield and yield attributies of transplant aman rice
Abstract: The small white lady’s-slipper (Cypripedium candidum) is an attractive endangered prone of extinction perennial orchid that inhabits in open areas of prairie and fen habitats. It occur relatively isolated populations at southern Ontario and southern Manitoba in Canada and eastern and western parts of the U.S.A. Different studies it revealed that there are 8 populations in southern Ontario and 15 populations in southern Manitoba. Among them one population in Manitoba and one in Ontario contain three-quarters of all of Canada’s small white lady’s slippers whereas rest 13 populations have less than 100 individuals and some of these consist of only a few plants along roadside ditches. The overall most significant risk factors for the viability of the populations are industrial, urban and agricultural development activities, encroachment by invasive weeds and woody plants, hybridization with other lady’s-slipper species, inbreeding due to small isolated populations, and illegal orchid collection. For protection and conservation of small white lady's-slipper in field level may require; maintain the currently protected sites, increase the public awareness, control the hybridization with other lady’s-slipper, a well defined habitat management strategies and a multi dimensional and institutional approach for implementation of conservation activities.
Abstract: English yew (Taxus baccata L.) is a native evergreen non-resinous gymnosperm long living dioecious, conifer tree species. It is one of the ancient European tree species and only a few centuries ago it was an integral part of forests throughout Europe. Human interventions and changes of the land-use system by modern technologies changed the structure and species composition of the temperate forests in Europe. The English yew populations are negatively affected by this process and decreased in most of their ranges though out Europe. Although yew is getting priority for conservation activities as an endangered tree species in Austria but the knowledge about conservation management is scarce. The aim of this study was to characterize selected yew populations from different geographic locations in the eastern Alps in order to study their ecological condition and genetic structure for conservation guideline. The yew populations showed shortcoming of certain regenerative height classes although most of the forests showed abundant number of one-year seedlings. The overall health condition of yew was good except Reserve B. For genetic study 9 isozyme gene loci were investigated and yew populations showed a high level of genetic variation (He = 0.267 and Ho=0.222) with a medium level of inbreeding (0.130). The overall most significant risk factors for the viability of the populations are browsing, tree competition, light availability, illegal cutting, and lack of public awareness. For protection and conservation of English yew in forest level may require continuous selective thinning for reduction of competition, protection from the herbivore, increase the public awareness and a multi dimensional and institutional approach for implementation of conservation activities.
Abstract: The available data on climate change over the past century indicating that the global temperature is increasing and it has a major impact on plant phenology as phonological events are strongly responsive to temperature. Scientist from the different discipline were observed changing of different phonological events such as timing of budburst, earlier spring flowering, earlier leaf unfolding, extended of average length of the growing season etc. Different experimental and modeling approaches have been developed to identify the mechanisms behind these changes and to make a precise projections concerning the consequences of climatic change. Here, we will discuss the recent progresses in the field of phonological research in responses to climatic changes in North America and draw a possible conclusion concerning the future tree phenology in the changing climatic condition.
Abstract: The mountain pine beetle (Dendroctonus ponderosae Hopkins) epidemic has altered lodgepole pine (Pinus contorta Dougl. Ex Loud. var. latifolia Engelm.) forests to an unprecedented extent in British Columbia. The current infestation of lodgepole pine by the MPB has been estimated at over 10.1 million hectares attacked and around 710 million m3 of mature pine killed to the end of 2007. After an MPB outbreak, advance regeneration typically forms a new canopy and stand; however the time needed is unknown. Stands likely contribute to ecological processes and future timber supply. Assessment of regeneration and growth of residual trees in stands after MPB attack is critical for: forecasting long-term development of attacked stands; selecting stands for growth improving silvicultural treatments; and forecasting impacts to hydrology, habitat, and vegetation types. This work reviews and synthesizes relevant investigations about the regeneration and growth status of MPB attacked lodgepole pine stands in central BC describing species composition and abundance, spatial distribution and overall health. Different investigations revealed that more than 40 % of stands dominated by pine have adequate advance regeneration after MPB attack. In most cases, the distribution of advance regeneration was clumped and species composition varied at stand and landscape levels. Most of the affected area will likely recover on its own and can provide midterm and long-term timber supply, as well as ecological services. However in some cases, effective management of advance regeneration is required following MPB attack to attain desired future stand level conditions and maintain ecological processes.
Abstract: English yew (Taxus baccata L.) is a native evergreen, dioecious, conifer tree species in temperate forest. Human interventions and changes of the land-use system by modern technologies changed the structure and species composition of the temperate forests in Europe. The Yew populations are negatively affected by this process and decreased from most of their ranges. At present it has cataloged as an endangered tree species throughout the globe. The aim of this research was to characterize 7 yew populations from different geographic locations in Austria in order to study their biodiversity with respect to stand and genetic structure as well as develop a conservation management plan. The stand structure of yew forests was illustrated with regards to different tree attributes (tree height, diameter at breast height, crown length, damages, vitality etc.) and the genetic variation was described by using isozyme gene marker. The Population Viability Risk Management (PVRM) framework was used to develop proper conservation and management actions by analyzing the current ecological and environmental condition. The Analytical Hierarchy Process (AHP) as part of the Population Viability Risk Management (PVRM) framework was used to evaluate different conservation strategies for selecting an appropriate management strategy with regards to the viability of yew. It was found that Austrian yew populations have shortcomings in certain regeneration classes although most of the forests showed abundant number of one-year seedlings. Considering the tree vitality of the adult yews the results indicate that the vitality is influenced by the inter-specific competition of the neighbouring trees. The yews with the lowest vitality are indicating the smallest mean distance and highest tree height differentiation to its neighbours. For the analysis of the genetic structure 9 isozyme gene loci were investigated. English yew showed a high level of genetic variation (He = 0.274 and Ho=0.238) with a medium level of inbreeding (0.130). The overall most significant risk factors for the viability of the population are browsing, tree competition, light availability, illegal cutting, and less people awareness. The PVRM framework allowed to evaluate six conservation strategies through a qualitative assessment of the probability for a decrease of the yew population along with four different environmental scenarios. In this context a management strategy combining selective thinning, protective measures, wild life management and public relation activities seems to be the most appropriate conservation activity for yew populations in Austria.
Abstract: English yew (Taxus baccata L.) is one of the ancient European tree species. Due to the intensive human land-use and the effects of forest management this species is declining sharply from most of its ranges and recognised as an endangered species. The aim of present study was to develop conservation measures by studying the different ecological and genetics parameters in the eastern Alps. The most significant result was shortcomings of certain regenerative height classes although all forests showed abundant number of one-year seedlings. Considering the tree health condition of the adult yews, results indicate that the vitality is influenced by the inter-specific competition of the neighbouring tree species. Besides these eastern Alps English yew populations showed a high level of genetic variation. From the investigation it was found that the major risk factors related to yew decline were competition, light availability, browsing by animal, illegal cutting, soil water relationship and lack of public awareness. For protection and conservation of English yew in forest level may require continuous selective thinning for reduction of competition, protection from the herbivore, increase the public awareness and a multi dimensional and institutional approach is needed for implementation of conservation activities.
Abstract: Homesteads agroforestry plays an important role in the rural economy of Bangladesh. Farmers grow different tree species in their homesteads for timber, fruits, fodder and fuel wood. A clear understanding of the physical characteristics and economic role of homestead agroforestry in rural livelihoods is vital for ensuring sustainable resource management. So, the aim of this work was to investigate the present status of homestead agroforestry and farmers’ preferences concerning species selection form a total of 150 randomly selected homesteads in central Bangladesh. The selected homesteads were categorized in four groups’ i.e, marginal, small, medium and large. The study results suggested that income and production of homestead agroforestry on a per hectare basis are influenced by the landholding size, farmers’ economic condition and level of education. Among the identified plant species almost 51 % were economically useful in the investigated area. The most common fruits species were mango (Mangifera indica, 31.3 %), jackfruit (Artocarpus heterophyllus, 18.6 %) coconut (Cocos nucifera, 9.7 %) and rest other types of local fruits species. Considering the timber species teak (Tectona grandis, 14.4 %), mahogany (Swietenia mahagoni, 11.6 %), koroi (Albizia procera, 18.3 %), eucalyptus, medicinal plants (Azadirachta indica, Terminalia arjuna) are also available. Farmers’ preferences considering the species selection are influenced by their economic condition and landholding size. The large and economically solvent farmers are more likely to prefer good quality timber producing species (teak, mahogany, etc) different types of fruits species and fuel wood whereas small and medium farmer always prefer to produce common fruits species and fast growing tree like (Koroi, Eucalyptus). From this study it is concluded that homestead agroforestry can be a potential subsistence income generating land-use practice in the study areas and farmers’ knowledge considering the selection of appropriate species composition can be enhanced by proper education and training.
Abstract: The English yew (Taxus baccata L.) is a native evergreen non-resinous gymnosperm long lived dioecious, conifer tree species in central Europe. At present it has come into prominence throughout the world due to its anti-cancer substance Taxol and it is recognised as an endangered tree species in Austria as well as all over the world. In our study one yew population was selected for studying details about its structure and genetics out of the 13 Austrian gene conservation forests. The population is found close to the Styrian capital Graz in the ecoregion “eastern and central hilly region of Styria” at the submontane vegetation belt. It represents a core population of yew, which has 2236 individual trees with a DBH range from 5 to 24,8 cm. The yew population is part of a mixed beech-conifer pole stand with a size of 4.6 ha. Bud samples from 109 trees as well as seed samples from 39 mother trees were taken in order to analyse the genetics of this relict population by means of isozyme gene markers. The results showed that the are discussed in terms of population dynamics in rare tree species.
Abstract: The English yew (Taxus baccata L.) is a native evergreen non-resinous gymnosperm long lived dioecious, conifer tree species in central Europe. At present it has come into prominence throughout the world due to its anti-cancer substance Taxol and it has recognised as an endangered tree species in Austria as well as most of its ranges. Structure of the yew relict population was illustrated in respect of different tree attributes. The genetic variation is described by using isozyme gene markers. It represents a core population of yew, which has 135 individual trees with a DBH range from 5.5 to 31.5 cm. Genotyping of individual trees has been carried out by analysis of bud materials with starch gel electrophoresis. For isozyme analysis 9 isozyme gene loci and 24 alleles were investigated. English yew showed high level of genetic variation with a mean number of alleles per locus (A/L) of 2.7, and 78 % of loci were polymorphic. The average expected heterozygosity was (He) 0.299 and mean observed heterozygosity (Ho) 0.270. Considering the high genetic diversity this population represents a valuable gene pool. So, conservation of English yew in forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.
Abstract: Population of slow growing long lived plants like English yew (Taxus baccata L.) typically received little attention in the past. Due to less interest, this species is now recognised as a rare and endangered species and declining sharply from most of its ranges. The aim of the present work was to describe the population structure in respect of different tree parameters (height, DBH, Vitality, etc) and genetic structure based on isozyme analysis. Genotyping of individual trees has been carried out by analysis of bud materials with starch gel electrophoresis. The average height and DBH of the yew population is 7.47 m and 17.0 cm respectively. The health condition is relatively good where 63 % of yew represent the very vital to vital condition. The natural regeneration is potentially high 5209 seedlings/ ha. For isozyme analysis 9 isozyme gene loci were investigated. English yew showed ordinary level of genetic variation with a mean number of alleles per locus (A/L) of 2.78, and 78 % of loci were polymorphic. The average expected heterozygosity was (He) 0.334 and the mean observed heterozygosity (Ho) 0.241. Considering the genetic diversity and stand structure the population represent a valuable gene pool for future conservation of Taxus baccata in Austria.
Abstract: English yew Taxus baccata L. is a slow growing evergreen dioecious wind pollinated conifer tree species in temperate forests. Now a day it has been catalogued as an endangered and prone to extinction in Austria as well as many other parts of Europe. Here we examine the distribution and population dynamics of English yews based on the natural population in an Austrian gene conservation forest. The investigated area is Beech dominating mixed forest consists of 15 different tree species. The estimated density of the Yew in the study plot was 492 individuals/hectors (DBH 5 or > 5 cm). The sex ratio of the Yew population was female biased and the average seed weight was 63.92 gm. The health condition is relatively good. Sensitive to herbivore browsing, light competition and slow to recover from disturbance Yew attains medium basal area (12 %) on this site. Conservation of Yew in forest level may require well-managed reserves and long-term rotations between harvest events, protection from the herbivore and reduction of competition, which will enhance the long-term viability of the species.
Abstract: The English yew (Taxus baccata L.) is an endangered rare tree species in Austria. This paper reports on a remarkable yew population found in a mixed beech-conifer forest stand at the low montane zone of the east Alpine mountains. The yew population is characterized on the basis of its structure, vitality and some genetic aspects within the stand. This study aims enlarging the basis for the conservation measures of genetic resources of yew.
Yew stand structure was illustrated in respect of height distribution, DBH distribution, crown length, crown cover, growth form and vitality. The genetic variation is described according to genetic traits by using isozyme gene markers.
We have found enormous number of individuals (492 yew trees / ha) in this area. The average DBH and height of the yew population is 8.8 cm and 6.3 m respectively. Considering the uneven-aged stand (DBH 5 or > 5 cm) yew represent 33 % of the total forest stand where as at young stage it corresponds to 29 % of total young population. The vitality of the yew showed extraordinary result, more than 79 % of the yews have been assessed as very vital to vital. Genotyping of individual trees has been carried out by analysis of bud materials with starch gel electrophoresis. For isozyme analysis 10 isozyme gene loci and 29 alleles were investigated. English yew showed high level of genetic variation with a mean number of alleles per locus (A/L) of 2.9, and 90 % of loci were polymorphic. The average expected heterozygosity was (He) 0.312 and mean observed heterozygosity (Ho) 0.286.
Considering the vitality, high level of genetic diversity, and relatively large population size, the Stiwoll population represents high endurance ability and a valuable gene pool for future conservation of Taxus baccata in Austria.
Abstract: The English yew (Taxus baccata L.) is one of the most ancient European tree species and although it rarely forms pure forest stands, only a few centuries ago it was an integral part of forests throughout much of Europe. Intensive human land-use has reduced the area of temperate forests in Europe and forest management changed the structure and species composition of the remaining forests. In that context yew populations decreased all over Europe with regard to the over use of man in the past centuries. As English yew is a rare tree species in Austria also gene conservation forests are used to maintain this endangered populations. The primary focus of this forests is the in-situ conservation of rare tree species by silvicultural treatments.
Vertical and horizontal differentiation resulting from positioning, mixture and competition determines the spatial variation in microclimatic conditions, food supply and structural complexity, thus directly and indirectly affecting the presence and abundance of species. Research studies on the structural diversity help to identify the effects of interspecific and intraspecific competition on the viablity of tree species. For improving the management in gene conservation forests this study compares the structural diversity of two important English yew populations in Austria.
A regular grid of permanent sample plots set up for the monitoring of both gene conservation forests (n=117 and 96) was used for data sampling. Three neighbouring trees of each individual male and female yew at each sample plots have been used to calculate structural indices like species mixture, diameter dominance and size differentiation according to Füldner (1995).
It was found that the vitality of each individual yew is directly influenced by the interspecific competition of the neighbouring tree species. The yews with a low vitality indicate the smallest mean distance to their neighbours and a small differentation according to the height. An increase of the height differentation and distance to neighbouring trees leads to a better vitality. A regular distribution provides maximal space and optimal growing conditions for each individual, while a clustered distribution leads to an increase of the competition.
It can be shown that a combination of different structural indicators supports an integrative assessment of the gene conservation forests, which leads to a better evaluation of management practices with respect to the viability of the yew population.
Abstract: Population viability risk management (PVRM) is used for the development and evaluation of six in situ conservation strategies for the maintenance of a gene conservation forest of an English yew population (Taxus baccata L.) in Styria, Austria. As part of the PVRM the Analytical Hierarchy Process (AHP) is used to evaluate the conservation strategies with regard to the viability of the yew population. The viability of the population is evaluated based on the results of an analysis of the current environmental, social and economical state and a characterization of the ecological parameters of its population. All relevant factors are structured and prioritized according to their impact on the viability of the yew population applying the AHP .The most significant risk factors for the viability of the population are illegal cutting, browsing, tree competition, light availability and genetic sustainability. Effects of the six conservation strategies are determined through a qualitative assessment of the probability of a decrease of the yew population along with four different environmental scenarios. In this context strategy IV combining selective thinning, protection measures, game control and public relation activities seems to be the most effective. The combination of PVRM with the AHP allows the rational analysis of conservation strategies for this endangered tree species.
Abstract: English yew (Taxus baccata L.) is a native evergreen non-resinous gymnosperm long living dioecious, conifer tree species. It is one of the ancient European tree species and only a few centuries ago it was an integral part of forests throughout Europe. Human interventions and changes of the land-use system by modern technologies changed the structure and species composition of the temperate forests in Europe. The English yew populations are negatively affected by this process and decreased in most of their ranges though out Europe. Although yew is getting priority for conservation activities as an endangered tree species in Austria the knowledge about conservation management is scarce. The aim of this research was to characterize selected yew populations from different geographic locations in Austria in order to study their biodiversity with respect to stand and genetic structure as well as to develop a conservation and management action plan. The stand structure of yew forests was illustrated with regards to different tree attributes (tree height, DBH, crown length, damage, vitality) and stand characteristics (mingling, vertical and horizontal structure). The genetic variation was described according to genetic traits by using isozyme gene marker. All these characteristics were used to describe the viability of yew populations. The Population Viability Risk Management (PVRM) framework was used to develop proper conservation and management actions by analyzing the current ecological and environmental condition. The Analytical Hierarchy Process (AHP) as part of the PVRM framework was used to evaluate different conservation strategies for selecting an appropriate management strategy with regards to the viability of yew. It was found that Austrian yew populations have shortcomings in certain regeneration classes although most of the forests showed abundant number of one-year seedlings. Considering the tree vitality of the adult yews the results indicate that the vitality is influenced by the inter-specific competition of the neighbouring tree species. The yews with the lowest vitality are indicating the smallest mean distance and highest tree height differentiation to its neighbours. For the analysis of the genetic structure 9 isozyme gene loci were investigated. English yew showed a high level of genetic variation (He = 0.274 and Ho=0.238) with a medium level of inbreeding (0.130). The overall most significant risk factors for the viability of the population are browsing, tree competition, light availability, illegal cutting, and less people awareness. The PVRM framework allowed to evaluate six conservation strategies through a qualitative assessment of the probability for a decrease of the yew population along with four different environmental scenarios. In this context a management strategy combining selective thinning, protective measures, wild life management and public relation activities seems to be the most appropriate conservation activity for yew populations in Austria.
Abstract: An experiment was conducted at the Agronomy Field Laboratory of Bangladesh Agricultural University, Mymensingh from July to December 2002 to study the effect of number of seedlings /hill and level of nitrogen from different sources on the performance of rice (BRRIdhan 32) under SRI method. The experiment was laid out in a randomized complete block design (RCBD) with four replications. The treatments used in the experiment consisted of (a) number of seedlings/ hill, i) Single seedling/ hill, ii) double seedlings/ hill, b) level of nitrogen from different sources i) BRRI recommended dose of prilled urea (150 kg/ ha), ii) 25% above BRRI recommended dose of prilled urea, iii) BRRI recommended dose of urea supper granules (1nos/ 4hill) , iv) 25% above USG (1.25nos/ 4hill) and v) compost (20 t /ha). Effect of number of seedlings/ hill was significant in respect of all the yield attributes and growth characters except panicle length number of total spikelets/ panicle and 1000-grain weight. Significantly higher grain yields were obtained from single seedling /hill (6.68 t / ha). The highest straw yield (9.16 t /ha) was obtained from 2 seedlings/ hill. Level of nitrogen from different sources significantly influenced all the growth characters and yield attributes number of total tillers/ hill, number of non effective tillers/ hill, panicle length, fertile spikelets /panicle, 1000-grain weight, grain yield, and harvest index were found to be the highest with BRRI recommended dose of urea super granules (USG). The interaction effect of number of seedling /hill and level of nitrogen did not differ significantly over all the growth characters
and yield attributes although the highest grain yield (7.28 t /ha) was produced from the BARRI recommended dose of USG (1nos / 4hill) with 1 seedling /hill.
Abstract: The main purpose of this survey was to investigation of farmer’s knowledge on rice cultivation in a village of Mymensingh sadar Thana besides attempt was made to explore the relationships between some selected characteristics of the farmers and their knowledge of rice. The interview schedule was used as the major instrument for data collection. Included it were also test for assessing knowledge of rice. The data was collected by a group of third year student, session-1994-95, during 1st April to 15th April 2000. Each of the eight selected characteristics of rice farmer was an independent variable. These were age, education, family size, farm size, farming experience, organizational participation, media exposure and Cosmo politeness. The majority of the farmers (46.66%) had moderate knowledge on rice cultivation, 33.33 percent had high knowledge and the rest 20 percent possessed low knowledge. Education, farm size, organizational participation, media exposure and Cosmo politeness of the farmer were positively related with their knowledge of rice cultivation. The rest independent variables – age, family size and farming experience had no relationships. To enrich farmers’ knowledge about rice cultivation by extension work seems to be satisfactory but there was more chance to increase their knowledge about rice cultivation.
Abstract: The experiment was carried out by the practical group No.-V, session 1994-95, final year 1998, to investigate the effect of level of nitrogen fertilizer on growth and yield of soybean at the Agronomy Field Laboratory, Bangladesh Agricultural University, Mymensingh during period from 18 December 2000 to 2 April 2001. The experiment consists of five levels of Nitrogen viz. 0,15, 30, 45 and 60 kg N ha-1. The experiment was laid out in randomize complete block design (RCBD) with four replications. Nitrogen has significant effect on all the characteristics except nodules plant-1. The nitrogen fertilizer at rate 45 kg N ha-1 produced highest number of nodules plant-1 (12.81), number of mature pod plant-1 (41.81), number of seeds pod-1 (2.67), seeds plant-1 (73.61), pod length (3.60), weight of pods plant-1 (14.31g), 1000-seed weight (130.65 g) and seed yield (1.83 t ha-1) than other doses of nitrogen fertilizer. The highest plant height (47.63 cm), weight of plant (23.46 g), weight of Stover plant-1 (11.35 g) and Stover yield (2.25 t ha-1) was recorded from 60 kg N ha-1. On the other hand highest number of immature pod plant-1 (1.47) was obtained from the control.
