Background:For controlling the resistance to insects,in particular carpophagous and phyllophagous caterpillars,using chemical pesticides has led to contamination of cotton area in Benin.Facing this problem,alternative...Background:For controlling the resistance to insects,in particular carpophagous and phyllophagous caterpillars,using chemical pesticides has led to contamination of cotton area in Benin.Facing this problem,alternative methods including the use of entomopathogenic fungi as biopesticide could be a sound measure to preserve the environment,biodiversity and ensure good quality of crops.Previous studies have revealed the insecticidal potential of the entomopathogenic Beauveria bassiana on some insect pest species.However,little is known about its effectiveness on cotton Lepidopteran pests.This review is done to learn more about B.bassina for its application in controlling cotton insect pests,especially Lepidopteran species.Main body:Different sections of the current review deal with the related description and action modes of B.bassiana against insects,multi-trophic interactions between B.bassiana and plants,arthropods,soil and other microbes,and biological control programs including B.bassiana during last decade.Advantages and constraints in applying B.bassiana and challenges in commercialization of B.bassiana-based biopesticide have been addressed.In this review,emphasis is put on the application methods and targeted insects in various studies with regard to their applicability in cotton.Conclusion:This review helps us to identify the knowledge gaps related to application of B.bassiana on cotton pest in general and especially in Lepidopteran species in Benin.This work should be supported by complementary laboratory bioassays,station and/or fields experiments for effective management of cotton Lepidopteran pests in Benin.展开更多
Water conservation starts from rationalizing irrigation,as it is the largest consumer of this vital source.Following the critical and urgent nature of this issue,several works have been proposed.The idea of most resea...Water conservation starts from rationalizing irrigation,as it is the largest consumer of this vital source.Following the critical and urgent nature of this issue,several works have been proposed.The idea of most researchers is to develop irrigation management systems tomeet the water needs of plants with optimal use of this resource.In fact,irrigation water requirement is only the amount of water that must be applied to compensate the evapotranspiration loss.Penman-Monteith equation is the most common formula to evaluate reference evapotranspiration,but it requiresmany factors that cannot be available in many cases.This leads to a trend towards behavior model estimation.System identification with control is one of the most promising applications in this axis.The idea behind this proposal depends on three stages:First,the estimation of reference evapotranspiration(ET0)by a linear ARX model,where temperature,relative humidity,insolation duration and wind speed are used as inputs,and ET0 estimated by Penman-Monteith equation as output.The results show that the values estimated by thismethodwere in good agreement with the measured data.The second part of this paper is tomanage the quantity of water.For this purpose,two controllers are used for testing,lead-lag and PID.To adjust the first controller and optimize the choice of its parameters,Nelder-Mead algorithm is used.In the last part,a comparative study is done between the two used controllers.展开更多
The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their st...The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their strength properties.This index is determined from the Atterberg limit tests,starting from the limits of liquidity and plasticity.However,the realization of the test considered as basic and simple,is not so much.The effects of the operator,the calibration of the apparatus and the environmental aspects during the tests affect the reliability and accuracy of the results.In this paper,the objective is to overcome these difficulties by evaluating the plasticity index of clay and loam soils by considering only the values of the liquid limit.Soil samples were collected from 0 to 5 m depth in the localities of the Khôdepression in Benin.On these samples,Atterberg limit tests were performed in the laboratory.Using MATLAB’s Curve Fitting Toolbox,linear,exponential and power prediction models were analyzed.The results showed that there is indeed a good correlation between the plasticity index and the liquid limit of the soils.For the linear model,it was observed R2 equal to 0.9891.For the exponential model,R2 is 0.98871 and for the power model 0.9802.A study of the residual plot validated the models found,as well as comparisons with well-known literature sources.Through the equations obtained,it is now possible to study the plasticity of soils in the Khôdepression only from the liquid limit,without determining the plasticity limit.展开更多
文摘Background:For controlling the resistance to insects,in particular carpophagous and phyllophagous caterpillars,using chemical pesticides has led to contamination of cotton area in Benin.Facing this problem,alternative methods including the use of entomopathogenic fungi as biopesticide could be a sound measure to preserve the environment,biodiversity and ensure good quality of crops.Previous studies have revealed the insecticidal potential of the entomopathogenic Beauveria bassiana on some insect pest species.However,little is known about its effectiveness on cotton Lepidopteran pests.This review is done to learn more about B.bassina for its application in controlling cotton insect pests,especially Lepidopteran species.Main body:Different sections of the current review deal with the related description and action modes of B.bassiana against insects,multi-trophic interactions between B.bassiana and plants,arthropods,soil and other microbes,and biological control programs including B.bassiana during last decade.Advantages and constraints in applying B.bassiana and challenges in commercialization of B.bassiana-based biopesticide have been addressed.In this review,emphasis is put on the application methods and targeted insects in various studies with regard to their applicability in cotton.Conclusion:This review helps us to identify the knowledge gaps related to application of B.bassiana on cotton pest in general and especially in Lepidopteran species in Benin.This work should be supported by complementary laboratory bioassays,station and/or fields experiments for effective management of cotton Lepidopteran pests in Benin.
文摘Water conservation starts from rationalizing irrigation,as it is the largest consumer of this vital source.Following the critical and urgent nature of this issue,several works have been proposed.The idea of most researchers is to develop irrigation management systems tomeet the water needs of plants with optimal use of this resource.In fact,irrigation water requirement is only the amount of water that must be applied to compensate the evapotranspiration loss.Penman-Monteith equation is the most common formula to evaluate reference evapotranspiration,but it requiresmany factors that cannot be available in many cases.This leads to a trend towards behavior model estimation.System identification with control is one of the most promising applications in this axis.The idea behind this proposal depends on three stages:First,the estimation of reference evapotranspiration(ET0)by a linear ARX model,where temperature,relative humidity,insolation duration and wind speed are used as inputs,and ET0 estimated by Penman-Monteith equation as output.The results show that the values estimated by thismethodwere in good agreement with the measured data.The second part of this paper is tomanage the quantity of water.For this purpose,two controllers are used for testing,lead-lag and PID.To adjust the first controller and optimize the choice of its parameters,Nelder-Mead algorithm is used.In the last part,a comparative study is done between the two used controllers.
文摘The plasticity index is an essential design parameter used as a standard input in fine-grained soil investigation programs.It is used to estimate the plasticity and physical properties of soils,and indirectly their strength properties.This index is determined from the Atterberg limit tests,starting from the limits of liquidity and plasticity.However,the realization of the test considered as basic and simple,is not so much.The effects of the operator,the calibration of the apparatus and the environmental aspects during the tests affect the reliability and accuracy of the results.In this paper,the objective is to overcome these difficulties by evaluating the plasticity index of clay and loam soils by considering only the values of the liquid limit.Soil samples were collected from 0 to 5 m depth in the localities of the Khôdepression in Benin.On these samples,Atterberg limit tests were performed in the laboratory.Using MATLAB’s Curve Fitting Toolbox,linear,exponential and power prediction models were analyzed.The results showed that there is indeed a good correlation between the plasticity index and the liquid limit of the soils.For the linear model,it was observed R2 equal to 0.9891.For the exponential model,R2 is 0.98871 and for the power model 0.9802.A study of the residual plot validated the models found,as well as comparisons with well-known literature sources.Through the equations obtained,it is now possible to study the plasticity of soils in the Khôdepression only from the liquid limit,without determining the plasticity limit.
