The authors would like to draw the reader's attention to an error in the following article: Selective harvesting is a feasible and profitable strategy even when grape and wine production is geared towards large fermentation volumes. Australian Journal of Grape and Wine Research 2011; 17: 298–305., , .
Table 3 of our recent paper contained an unfortunate error which, if left uncorrected, could create the impression of elevated benefits accruing to Murray Valley grapegrowers from selective harvesting. The correct table is as follows:
Partial gross margin analysis for grapegrowing of selectively harvesting fruit for ‘super premium’ (LVY) and ‘premium’ (HVY A) wines assuming grape prices of $423 and $520 for the two grades of fruit
|LVY||HVY A||HVY A|
|Harvest cost/t ($)||99||30||30|
|Harvest cost ($)||51 t||5,049|
|Total harvest cost ($)||9,699||6,180|
|Grape Price/t ($)||‘Premium’||423||423|
|Grape value ($)||51 t||26,520|
|Total grape value ($)||92,085||87,138|
|Grape value less harvest cost ($)||82,386||80,958|
|Net benefit of selective harvest ($)||1,428||(1.8%)|
Clearly, correction of this error has greatly reduced the apparent benefit to grapegrowers of selective harvesting from 9.4% down to 1.8% and so emphasises the fact that the greatest benefit from such strategies accrues to winemakers; note that the benefit to winemakers (Table 2) was correctly stated in the paper.
We re-iterate that, in our paper, we deliberately took a conservative view and elevated the costs of selective harvesting in an attempt to avoid over-selling the potential benefits. Thus, an opportunity cost was applied to the use of a less-than-full fermenter, whilst the selective harvest in the example discussed required double pass harvesting which added $30/t to the harvesting cost; in many situations, neither of these additional costs may apply. A useful way of considering the economics of selective harvesting from a grower perspective is to consider the break-even price differential between fruit grades that is required for this strategy to be potentially worthwhile. Using the example discussed in our paper, this price differential equates to the additional harvest cost, or $69/t; if double pass harvesting were not required, then the price of higher grade fruit would only need to be $39/t higher than that of lower grade fruit for selective harvesting to deliver at least some benefit to the grower (a 3.7% benefit in our example from Deakin Estate). These comments notwithstanding, the fact remains that for a grower to gain real benefit from selective harvesting, they would need to embark on the strategy with the full cooperation and knowledge of the winemaker – as was made clear in the original paper.