Influence of plant traits on production costs and profitability of strawberry in southeast Queensland

In Queensland the subtropical strawberry (Fragaria×ananassa) breeding program aims to combine traits into novel genotypes that increase production efficiency. The contribution of individual plant traits to cost and income under subtropical Queensland conditions was investigated, with the overall goal of improving the profitability of the industry through the release of new strawberry cultivars. The study involved specifying the production and marketing system using three cultivars of strawberry that are currently widely grown annually in southeast Queensland, developing methods to assess the economic impact of changes to the system, and identifying plant traits that influence outcomes from the system. From May through September P (price; $punnet⁻¹), V (monthly mass; tonne of fruit on the market) and M (calendar month; i.e. May=5) were found to be related (r²=0.92) by the function (±SE) P=4.741(±0.469)−0.001630(±0.0005)V−0.226(±0.102)M using data from 2006 to 2010 for the Brisbane central market. Both income and cost elements in the gross margin were subject to sensitivity analysis. ‘Harvesting’ and ‘Handling/Packing’ ‘Groups’ of ‘Activities’ were the major contributors to variable costs (each >20%) in the gross margin analysis. Within the ‘Harvesting Group’, the ‘Picking Activity’ contributed most (>80%) with the trait ‘display of fruit’ having the greatest (33%) influence on the cost of the ‘Picking Activity’. Within the ‘Handling/Packing Group’, the ‘Packing Activity’ contributed 50% of costs with the traits ‘fruit shape’, ‘fruit size variation’ and ‘resistance to bruising’ having the greatest (12–62%) influence on the cost of the ‘Packing Activity’. Non-plant items (e.g. carton purchases) made up the other 50% of the costs within the ‘Handling/Packing Group’. When any of the individual traits in the ‘Harvesting’ and ‘Handling/Packing’ groups were changed by one unit (on a 1–9 scale) the gross margin changed by up to 1%. Increasing yield increased the gross margin to a maximum (15% above present) at 1320gplant⁻¹ (94% above present). A 10% redistribution of total yield from September to May increased the gross margin by 23%. Increasing fruit size increased gross margin: a 75% increase in fruit size (to ≈30g) produced a 22% increase in the gross margin. The modified gross margin analysis developed in this study allowed simultaneous estimation of the gross margin for the producer and gross value of the industry. These parameters sometimes move in opposite directions.