Plant-to-plant variability is a crop stability component.The objective of this study in maize(Zea mays L.)was to test the validity of the theoretical background of the hypothesis that the coefficient of variation(CV)f...Plant-to-plant variability is a crop stability component.The objective of this study in maize(Zea mays L.)was to test the validity of the theoretical background of the hypothesis that the coefficient of variation(CV)for grain yield per plant and mean yield are connected exponentially,following the Taylor’s Power Law(TPL)Model.Field experimentation was conducted across two sites,two seasons,and two planting densities.Densities were the main plots,corresponding to the typical practice of 8.89 plants m–2(TCD)and the low-input optimal of 5.33 plants m–2(LCD),while hybrids were the subplots.Data from 26 subplots in the first site averaged CV values of 22.6%at the TCD and 21.9%at the LCD,and mean yields of 19.1 and 13.9 t ha–1,respectively,following the TPL Model.The same was true for the second site,with average CVs and means of 41.5%and 14.3 t ha–1 at the TCD and 36.8%and 11.5 t ha–1 at the LCD.A test was performed on the simple correlation between the logarithms of variances and their respective means to investigate whether there is a systematic variance dependence on mean,thus questioning the reliability of TPL.The validity of TPL was verified in the first site.Nevertheless,there was a systematic dependence of yield variance on mean yield in the second site,implying that the CV-yield correlation might be not biologically meaningful.Conversion of the variance to remove its dependence on the mean did not validate the CV-yield negative relationship,meaning that caution is needed when interpreting the CV as a stability index for intra-crop variation.Whether the determinant factor of invalidity of TPL was the extensive intra-crop variation in the lower yielding second site can be assessed in future research.展开更多
Opencast mining is important for local and global economy,but this operation mostly and inevitably leads to substantial environmental damage.Potential future use of the post-mining lands basically depends on the natur...Opencast mining is important for local and global economy,but this operation mostly and inevitably leads to substantial environmental damage.Potential future use of the post-mining lands basically depends on the nature of the land,soil conditions,and communal structure of nearby surrounding to be rehabilitated by technical,biological,agricultural means or forestry applications.Vegetation cover has significant functions on post-mining landscapes so,in order to reduce the probability of negative impacts,selection of suitable plant material,which may be preferably native but also introduced plant species,is critical.In West Macedonia Lignite Centre,about 1,500 ha of these land has already reforested by the Public Power Corporation S.A.,with Robinia pseudacacia L.,one of the most criticized non-native tree species in Europe,because its rootstocks spread into neighbouring areas,repressing native species.The tree is an excellent species for revegetating poor or damaged soils and its fast-growing nature,makes it popular for former lignite mine reclamation,reforestation and erosion control.Robinia forests represent a valuable nectar and pollen source in late spring for many insects,especially Hymenoptera,such as Apis mellifera.That has increased dramatically the regional honey producing potential.In this study,the annual potential honey production of 1,500 ha black locust forests established in reforested old mines land,was estimated from 50,000 to 70,000 kg honey,depending on the year,which is sufficient for up to1,000 bee hives to survive for one year.For the efficient utilization of this valuable honey producing source by the beekeepers,a plan should be developed,to facilitate accessibility to the region and proper beehives dispersion.展开更多
基金the European Union and Greek National Funds through the Operational Program Competitiveness,Entrepreneurship and Innovation,under the Call Research-Create-Innovate(Project Code:T1EDK-00739).
文摘Plant-to-plant variability is a crop stability component.The objective of this study in maize(Zea mays L.)was to test the validity of the theoretical background of the hypothesis that the coefficient of variation(CV)for grain yield per plant and mean yield are connected exponentially,following the Taylor’s Power Law(TPL)Model.Field experimentation was conducted across two sites,two seasons,and two planting densities.Densities were the main plots,corresponding to the typical practice of 8.89 plants m–2(TCD)and the low-input optimal of 5.33 plants m–2(LCD),while hybrids were the subplots.Data from 26 subplots in the first site averaged CV values of 22.6%at the TCD and 21.9%at the LCD,and mean yields of 19.1 and 13.9 t ha–1,respectively,following the TPL Model.The same was true for the second site,with average CVs and means of 41.5%and 14.3 t ha–1 at the TCD and 36.8%and 11.5 t ha–1 at the LCD.A test was performed on the simple correlation between the logarithms of variances and their respective means to investigate whether there is a systematic variance dependence on mean,thus questioning the reliability of TPL.The validity of TPL was verified in the first site.Nevertheless,there was a systematic dependence of yield variance on mean yield in the second site,implying that the CV-yield correlation might be not biologically meaningful.Conversion of the variance to remove its dependence on the mean did not validate the CV-yield negative relationship,meaning that caution is needed when interpreting the CV as a stability index for intra-crop variation.Whether the determinant factor of invalidity of TPL was the extensive intra-crop variation in the lower yielding second site can be assessed in future research.
文摘Opencast mining is important for local and global economy,but this operation mostly and inevitably leads to substantial environmental damage.Potential future use of the post-mining lands basically depends on the nature of the land,soil conditions,and communal structure of nearby surrounding to be rehabilitated by technical,biological,agricultural means or forestry applications.Vegetation cover has significant functions on post-mining landscapes so,in order to reduce the probability of negative impacts,selection of suitable plant material,which may be preferably native but also introduced plant species,is critical.In West Macedonia Lignite Centre,about 1,500 ha of these land has already reforested by the Public Power Corporation S.A.,with Robinia pseudacacia L.,one of the most criticized non-native tree species in Europe,because its rootstocks spread into neighbouring areas,repressing native species.The tree is an excellent species for revegetating poor or damaged soils and its fast-growing nature,makes it popular for former lignite mine reclamation,reforestation and erosion control.Robinia forests represent a valuable nectar and pollen source in late spring for many insects,especially Hymenoptera,such as Apis mellifera.That has increased dramatically the regional honey producing potential.In this study,the annual potential honey production of 1,500 ha black locust forests established in reforested old mines land,was estimated from 50,000 to 70,000 kg honey,depending on the year,which is sufficient for up to1,000 bee hives to survive for one year.For the efficient utilization of this valuable honey producing source by the beekeepers,a plan should be developed,to facilitate accessibility to the region and proper beehives dispersion.
