Study On Rapeseed Yield Estimation Based On Spectral Technique

China is one of the largest countries of planting rapeseed area in the world,in recent years,with the fall of the rapeseed planting area,oil crops production is far not enough to catch the demand of domestic consumption but need huge imports.It is significant to estimate the yield of rapeseed oil for stabilizing the edible oil market and planning ahead for oil imports,therefore,it is important to estimate the precise and rapid rate of oil crop production.Target to estimate the rapeseed yield in this study guided by the spectroscopy theory,high oleic acid rapeseed 708 has been as the research object with the method of field experiment using the spectral instrument for spectral data acquisition and processing,kinds of analysis methods and software have been used to dispose and analyze the spectral data of five periods of seedling,bolting,blooming,flowering and pod,respectively.With the utilization of average treatment,vegetation index calculation,correlation analysis,etc.,the yield model of the spectrum characteristic curve and the flowering period and the period of the pod period were obtained.Major work and results as follows:(1)ASD spectrometer with high spectral remote sense has been employed to acquiring spectral data to get rapeseed seedling and bolting stage,early flowering,coated and pods phase spectrum curve data through a certain process to obtain basic spectral characteristics of rapeseed,rapeseed coated with pod stage was make use of vegetation index yield estimate.(2)The oil dish has the basic characteristics of four peaks and four valleys which can be used to identify the oil dishes.In 350-980 nm band from seedling stage to bolting stage,and then to the early flowering,rapeseed spectrum value increases slowly from the trend with rapeseed growth,increased rapeseed biomass and leaf area index,enhance overall photosynthesis;And in full bloom,the maximum spectral values,may be the golden rapeseed in full bloom makes the spectral detector receives the yellow band energy is increased,result in visible light band reflectance increases;Decreased significantly after the pods,spectral values,rapeseed has withered,rapeseed leaf decreased,leaf area index decreased significantly,basic of rapeseed pod canopy spectral information.Therefore,the flowering and pod periods may be the best time to estimate the production of oil.(3)The plant height,pod number,three kinds of production factors has a close relationship between spectral characteristic parameters,and grains that factor from the data processing results correlation was small,basic need not do production estimate.The estimation effect of the spectral parameter of the oil and vegetable pod is better than that of the flowering period,especially the yield effect of the quadratic polynomial model of the pod.The second polynomial model of the pod phase is best suited for the spectral technique,and the flowering period and other models can be used as supplementary estimates.