Rapid Estimation of Cabbage Head Volume across a Population Varying in Head Shape: A Test of Two Geometric Formulae

Volume measurements are useful in crop quality management because they offer three-dimensional estimates of commodity size, which is often closely related to commodity weight and density. The objective of this study was to compare volume estimates calculated with the sphere and spherical ellipsoid volume formulae with direct measures of volume via water displacement across a population of cabbage (Brassica oleracea Capitata Group) heads varying widely in shape. A total of 157 heads with polar (P) : equatorial (E) diameter ratios ranging between 0.5 (fl at) to 2.1 (tall) were harvested at horticultural maturity from plants grown in 2002 and 2003 at the Ohio Agricultural Research and Development Center (OARDC) in Wooster, Ohio. The sphere formula underestimated volume in heads with P:E ratios 1. Use of the spherical ellipsoid formula reduced the shapedependency of volume estimates and was determined to be a valuable tool for the accurate, precise, and rapid measurement of head volume.