For Australian apple and pear growers, Harvista 1.3SC is becoming an increasingly important crop management tool for those wanting to reduce fruit drop, improve fruit colour or manipulate harvest timing to help manage harvest logistics.
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Harvista 1.3SC from AgroFresh is a plant growth regulator, which works by slowing the ripening process, allowing fruit to remain on the tree longer without compromising quality.
As growers know, this can be beneficial as it can provide the time needed to develop fruit colour and size, reduce greasiness, or to optimise operations, including labour usage, during the harvest window.
Control.
4 day application.
Dr Hannah James, who has worked with Harvista1.3SC, since its initial commercialisation in the US in 2010, explains: Harvista works by binding to ethylene receptors in the fruit and as a result, the ripening process is slowed.
Hannah says depending on application times, Harvista can delay harvest for up to 21 days and, in some varieties, it is effective in reducing fruit drop.
“Although the varietal response can differ, the common benefit is the opportunity to have some control over harvest timing,” she says.
“This allows harvest operations to flow more smoothly, and labour use adjusted, whilst optimising quality outcomes which ultimately affect fruit storage and market performance.”
Brent Reeve from Redland Apples in Shepparton, in Victoria’s Goulburn Valley, has been using Harvista for a number of seasons.
“We’ve been successful in using Harvista to delay harvest into the cooler months of autumn,” he explains.
“This allows fruit to develop better colour and can have a real impact on the returns we receive.
“Harvista also helps us spread our harvest, while maintaining fruit quality, meaning we are in a better position to manage labour and harvest costs.”
Timing Harvista applications
Timing is crucial to maximise the effectiveness of Harvista. The application window and optimal timing will depend on the variety and what you are wanting to achieve.
Harvista can be applied from 21 days to three days before anticipated harvest, before significant fruit drop or ripening occurs. It can also be applied after the first pick to provide flexibility with picking dates with the remaining crop. Withholding periods still need to be observed.
Starch testing of the fruit is the best method to determine application timing. Testing should start about two weeks before expected application time and be repeated every five to seven days. Although not as accurate, some growers also use historical harvest dates and adjust for the timing of the current season.
Harvista has a three-day withholding period in Australia.
AgroFresh Australian country manager Greg Montgomery says “Harvista has a unique formulation to make application easier. It differs from typical orchard sprays, so having the right approach and equipment is important to ensure efficacy.”
Growers should also note the effects of Harvista may not become evident until several days post-application and use of other plant growth regulators with Harvista should be evaluated on a case-by-case basis.
AgroFresh has a team of technical account managers across Australia who are available to advise growers on specific benefits and requirements for different varieties, regions and achieving desired outcomes.
AgroFresh’s trial results (see graph) also show how Harvista applications in a Gala orchard can help manage starch levels in fruit.
Applying Harvista early (18 days before harvest) delayed maturity development in Gala by approximately 20 days. After this period, the effect diminished and starch breakdown accelerated.
The late application of Harvista (four days before harvest) was still very effective at arresting the progress of maturation even though the fruit maturity was more advanced at the time of application.
Applying Harvista late (four days pre-harvest) remains very effective in slowing maturation, despite the fruit being more advanced in maturity when it was applied.
This orchard example illustrates that a second application of Harvista on previously treated fruit – with treatments applied at 18 and four days before harvest - can significantly prolong harvest maturity.
For multi-pick varieties such as Gala, applying Harvista earlier tends to deliver more consistent results because fruit maturity is more uniform at the time of application.
