Estimation of Cotton Yield Using Two-Phase Sampling Approach

Cotton, a multiple picking crop, is grown in around nine States in India.The existing procedure of estimation of average yield of cotton is based on crop cutting experiment (CCE) approach, which utilizes data on all pickings, is cumbersome and cost prohibitive.The two-phase sampling approach can be gainfully employed in this case by collecting data on picking, which has highest correlation with the total pickings yield on a larger sample and the total pickings yield data on a smaller sample.Accordingly, a stratified two-stage twophase sampling design has been proposed for selection of representative sample and an appropriate estimation procedure, based on two-phase sampling regression estimator, has been developed for estimation of average yield of cotton at district level.Utilizing the data of survey conducted in the Aurangabad and Amravati district of Maharashtra State and Adilabad and Guntur district of Andhra Pradesh wherein third picking data was collected on a larger sample and total pickings yield data on a smaller sample.An expression for optimum number of villages for larger and smaller samples has been obtained by minimizing cost subject to fixed percentage standard error of the estimates.These have been worked out empirically as well.