The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its ...The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its shoot and root structure helps it to capture light more effectively in winter and early spring, and to adapt to the soil moisture conditions in its narrow habitat. Another medicinal plant, Anthriscus sylvestris, is of similar economic importance but commonly distributed widely. In contrast to C. smyrnioides, it has low structural plasticity. It is also specialized to adapt to the moist and sunny environment, where habitat, such as the banks of creeks and rivers, is abundant.展开更多
in recent years, there have been draniatic increases in the production of NorthAmerican ginseng around the tvorld. These increases and the expectation of their continuation havegiven rise to a need to critically evalu...in recent years, there have been draniatic increases in the production of NorthAmerican ginseng around the tvorld. These increases and the expectation of their continuation havegiven rise to a need to critically evaluate all aspects of North American ginseng (Panar quinquefoliumL.) production. Employing a system approach, the production of North American ginseng can be di-vided into its principal components that include seed preparation and planting, growing environmentcreation and maintenance, plant health maintenance, harvest and post-harvest activities, and productprocessing. As competitive industry forces are beginning to result in increased global competition, itis prudent to carefully assess both the strengths and weaknesses of the North American ginseng pro-duction system. It is clear that the utilization of appropriate technology will be a key to future industrysuccesses and the continuity of successful economic development that is associated with the industry.It is recognized that careful technological choices and changes will be required to successfully facethe challenges of an ever increasingly competitive global ginseng marketplace.展开更多
This study analyzed the impact of participatory plant breeding （PPB） and participatory variety selection （PVS） on the adoption of improved sweetpotato varieties （ISPV） in central Uganda. The study quantitatively...This study analyzed the impact of participatory plant breeding （PPB） and participatory variety selection （PVS） on the adoption of improved sweetpotato varieties （ISPV） in central Uganda. The study quantitatively assessed how the two approaches influence farmers＇ uptake of the improved sweetpotato varieties and also determined other factors influencing this adoption. This was done by estimating a robust standard errors logit model. Both PPB and PVS positively and significantly influenced the likelihood of adoption of improved sweetpotato varieties at 5% and 10% levels, respectively. Other variables that positively influenced the adoption are extension services, training in sweetpotato production, farming experience, and off-farm income of the household. Farmers who participated in the plant breeding and variety selection processes were 37 and 6.7 times more likely to adopt the improved sweetpotato varieties than those who had not, respectively. Farmers who were trained specifically in sweetpotato production were 8.8 times more likely to adopt the improved varieties than those who had not received this type of training.展开更多
Magnetic field effects on different plant species have been subject of many studies in the last decade. Magnetic fields are known to induce changes in plant metabolism, growth and productivity. In this study, effect o...Magnetic field effects on different plant species have been subject of many studies in the last decade. Magnetic fields are known to induce changes in plant metabolism, growth and productivity. In this study, effect of magnetic field on date palm weight and water content has been investigated. Seedlings of date palm were treated with two types of magnetic fields in two separate experiments. In the first experiment, seedlings were treated with static magnetic field SMF using electromagnetic circuit set to produce three levels of magnetic field intensities 10, 50 and 100 mT for different durations （0, 30, 60, 120, 180 and 240 min）. In the second experiment seedlings were treated with alternating magnetic field AMF, using magnetic resonance imaging providing 1500 mT for 0, 1, 5, 10 and 15 min. After two months of exposure, plants growth parameters （fresh, dry weights and water content for both leaves and roots） were recorded. The measurements revealed that leaf fresh, dry weight and water content increased significantly in response to SMF treatment. Similarly, roots fresh weight and water content were increased significantly; however roots dry weight increasing were insignificant. In the second experiment, AMF has affected plant growth all parameters were increased significantly. Measurements reached the highest level at 15 min of exposure. This study revealed that magnetic fields affect date palm growth parameters by increasing osmotic pressure and water potential which increase water absorption and enhance flesh weight.展开更多
Sugarcane advanced variety trials are planted across several locations and harvested for several crop-years to determine genotype by environment interaction and yield stability. Previous studies describe methods for s...Sugarcane advanced variety trials are planted across several locations and harvested for several crop-years to determine genotype by environment interaction and yield stability. Previous studies describe methods for simultaneous screening for yield and stability but did not use parametric statistical tests for comparing genotypes. The objective of this study was to describe a parametric statistical method for simultaneous screening of sugarcane genotypes for yield and stability. Data from 26 crops were collected from trials established at five locations and harvested in the plant, first, second, third and fourth ratoon crops. The mixed procedure of SAS was used for data analysis. The intercept and slope were used to represent yield and stability, respectively. There were significant （P 〈 0.05） differences in yield and stability among the genotypes. Test genotypes were classified into groups of genotypes that produced high yield, or high stability or both. The method provides fast statistical tests for simultaneous screening for yield and stability. The method was also used to compare two genotypes, an application for variety choice at time of release.展开更多
文摘The endangered medicinal herb, Changium smyrnioides can only be found in deciduous forest gaps within the middle to northern subtropical broad-leaved evergreen forest zone of China. The considerable plasticity of its shoot and root structure helps it to capture light more effectively in winter and early spring, and to adapt to the soil moisture conditions in its narrow habitat. Another medicinal plant, Anthriscus sylvestris, is of similar economic importance but commonly distributed widely. In contrast to C. smyrnioides, it has low structural plasticity. It is also specialized to adapt to the moist and sunny environment, where habitat, such as the banks of creeks and rivers, is abundant.
文摘in recent years, there have been draniatic increases in the production of NorthAmerican ginseng around the tvorld. These increases and the expectation of their continuation havegiven rise to a need to critically evaluate all aspects of North American ginseng (Panar quinquefoliumL.) production. Employing a system approach, the production of North American ginseng can be di-vided into its principal components that include seed preparation and planting, growing environmentcreation and maintenance, plant health maintenance, harvest and post-harvest activities, and productprocessing. As competitive industry forces are beginning to result in increased global competition, itis prudent to carefully assess both the strengths and weaknesses of the North American ginseng pro-duction system. It is clear that the utilization of appropriate technology will be a key to future industrysuccesses and the continuity of successful economic development that is associated with the industry.It is recognized that careful technological choices and changes will be required to successfully facethe challenges of an ever increasingly competitive global ginseng marketplace.
文摘This study analyzed the impact of participatory plant breeding （PPB） and participatory variety selection （PVS） on the adoption of improved sweetpotato varieties （ISPV） in central Uganda. The study quantitatively assessed how the two approaches influence farmers＇ uptake of the improved sweetpotato varieties and also determined other factors influencing this adoption. This was done by estimating a robust standard errors logit model. Both PPB and PVS positively and significantly influenced the likelihood of adoption of improved sweetpotato varieties at 5% and 10% levels, respectively. Other variables that positively influenced the adoption are extension services, training in sweetpotato production, farming experience, and off-farm income of the household. Farmers who participated in the plant breeding and variety selection processes were 37 and 6.7 times more likely to adopt the improved sweetpotato varieties than those who had not, respectively. Farmers who were trained specifically in sweetpotato production were 8.8 times more likely to adopt the improved varieties than those who had not received this type of training.
文摘Magnetic field effects on different plant species have been subject of many studies in the last decade. Magnetic fields are known to induce changes in plant metabolism, growth and productivity. In this study, effect of magnetic field on date palm weight and water content has been investigated. Seedlings of date palm were treated with two types of magnetic fields in two separate experiments. In the first experiment, seedlings were treated with static magnetic field SMF using electromagnetic circuit set to produce three levels of magnetic field intensities 10, 50 and 100 mT for different durations （0, 30, 60, 120, 180 and 240 min）. In the second experiment seedlings were treated with alternating magnetic field AMF, using magnetic resonance imaging providing 1500 mT for 0, 1, 5, 10 and 15 min. After two months of exposure, plants growth parameters （fresh, dry weights and water content for both leaves and roots） were recorded. The measurements revealed that leaf fresh, dry weight and water content increased significantly in response to SMF treatment. Similarly, roots fresh weight and water content were increased significantly; however roots dry weight increasing were insignificant. In the second experiment, AMF has affected plant growth all parameters were increased significantly. Measurements reached the highest level at 15 min of exposure. This study revealed that magnetic fields affect date palm growth parameters by increasing osmotic pressure and water potential which increase water absorption and enhance flesh weight.
文摘Sugarcane advanced variety trials are planted across several locations and harvested for several crop-years to determine genotype by environment interaction and yield stability. Previous studies describe methods for simultaneous screening for yield and stability but did not use parametric statistical tests for comparing genotypes. The objective of this study was to describe a parametric statistical method for simultaneous screening of sugarcane genotypes for yield and stability. Data from 26 crops were collected from trials established at five locations and harvested in the plant, first, second, third and fourth ratoon crops. The mixed procedure of SAS was used for data analysis. The intercept and slope were used to represent yield and stability, respectively. There were significant （P 〈 0.05） differences in yield and stability among the genotypes. Test genotypes were classified into groups of genotypes that produced high yield, or high stability or both. The method provides fast statistical tests for simultaneous screening for yield and stability. The method was also used to compare two genotypes, an application for variety choice at time of release.
