Modelling price obtained for bananas
by
Janet Giles
Queensland Department of Primary Industries
Coauthors: Tony Swain, Roger Broadley

Data collected by a wholesaler from 1030 consignments over a period of 324 days in 2000 were examined in an attempt to ascertain what factors determined prices paid to growers for Ladyfinger bananas. Sample boxes from each consignment were assessed for 22 types of defect, presentation, bloom, 4 packaging attributes and, for 323 consignments, pulp temperature. Carton weight, number of cartons in each grower consignment and price for 3 size grades (extra large, large and medium), and date sold were also recorded.

Prices obtained per kg for different banana size categories were highly correlated. Date sold had a large influence on price obtained, much of this related to seasonal fluctuations in supply. A smoothing spline of order 8 (P<0.001) explained 43% of variation in the price per kg of extra large fruit. Total defects per kg or quality (derived from total defects, presentation and bloom) were most significant at explaining further variation, with carton size and pulp temperature also influential. The contribution of individual defects and stability of coefficients were investigated in an attempt to obtain useful data for growers on the premiums paid for reduction of defects and improved presentation.

Date received: August 29, 2002