ON THE VOLUME OF RASPBERRY FRUIT SAMPLE FOR ESTIMATING THE AVERAGE MASS OF ONE FRUIT

摘要

The experimental work was carried out in 2006 in 400 m2 raspberry plantation of the primocane-fruiting "Lyulin" variety. Plants were supplied with water and fertilizers through a drip irrigation system. The investigation included seven irrigation regimes in four replications. During the mam phenophases -intensive growth, blossom, and fruit ripening - water application rates recovered 100%, 75%, and 50% of the raspberry crop evapotranspiration respectively. The minimum sample volume was estimated using the method of iterations. The relative standard error of the mean and the confidence probability P were predefined while the mean Xav and the standard deviation S were obtained in a series of preliminary experiments. Samples with volume of 100 randomly collected fruits were taken from each of the investigated variants. The mass of each fruit was measured and Xav N S of the seven 100-member and one 700-member samples were calculated. The minimum sample volume vas estimated both for each of the investigated variants, in order to be assessed the impact of the applied irrigation regimes, and for the entire plantation. The frequency distribution in all variants was close to the normal distribution, which confirmed the reliability of the used procedure. Obtained results are given in a table for values of the relative error from 1% to 10% and confidence probabilities 95%, 99%, and 99.9%. The sample volume has to be enlarged for plants subjected to water stress.