Time of harvest is one of the most critical and challenging viticultural decisions for table grape producers.
Assessing grape maturity requires experience to ensure sampling is conducted appropriately, and genuinely reflects the maturity of the crop.
As maturity varies year to year, and with a third straight La Niña season expected, milder and cloudier conditions may lead to the late maturation of grapes, and therefore delayed harvest.
This is nothing new for table grape producers, who were faced with the same issue for the 2021/22 season. However, growers must do everything in their power to ensure consistency and quality procedures are met to enhance consumer acceptance, both domestically and internationally.
Consumer acceptability of grapes fell last season to 71 per cent, below the 80 per cent goal set as part of the table grape maturity project, funded by Hort Innovation with funds from the table grape research and development levy and contributions from the Australian Government.
“Consumers are ready and waiting to switch to other fruit categories,” project lead Tristan Kitchener, of Kitchener Partners, said.
“Their loyalty lies in fruit categories with higher consistency of fruit maturity and quality.
“We have known for several years now that when a customer has a negative eating experience, it takes them 14 weeks to repurchase and re-enter the category. In the 2021/22 season, however only 60 per cent of consumers repurchased at that point compared to 80 per cent in previous seasons.
“While table grapes didn’t meet the consumer acceptability goal, things could have been much worse if the industry hadn’t implemented minimum maturity standards three years ago.”
Technical lead Andreas Klieber, of Quality Associates, added: “In-field testing and store sampling showed that Brix levels appeared to steadily increase initially, only for weather conditions to delay or stop further increases.
“Ongoing testing in the lead up to the harvest and adjusting planned harvest dates was crucial.”
Australian Table Grape Association chief executive Jeff Scott said maturity sampling pre-harvest and harvest was one tool growers have in their toolbox to ensure they are only sending ripe fruit to market.
“The ATGA has made small adjustments to its maturity testing procedures at harvest to give growers the confidence in their sampling techniques,” Mr Scott said.
“Leading up to harvest, testing at various times of the day and in various locations in your patch ensures you’re getting a representative sample.
“Make sure harvest workers are experienced in or informed about maturity testing accurately, and that at harvest time they take a larger sample batch to work with.”
The ATGA has increased the number of berries to be collected for a sample, as set out in the 2022 maturity testing procedures, which are available on the ATGA website.
Mr Klieber added: “A larger sample count means more reliable data, less rejections, greater consumer acceptability, and, therefore, less risk for producers.
“Take berries from all the parts of the bunch (top, middle and bottom) and also sample from the bottom of the bag to have a representative sample. Don’t just choose berries that look good. You can’t judge a book by its cover when it comes to the sweetness of grapes.”
