In Australia, the plant growth regulator ReTain® (AVG) is commonly used on stone fruit such as peaches and nectarines. By spraying ReTain a few weeks prior to harvest, growers can allow the peaches and nectarines to develop excellent flavor, but they don’t have to worry about the fruit getting too soft.
Some California growers also use ReTain in situations where they are growing varieties that are prone to soft tip. A ReTain application two weeks prior to harvest can prevent soft tip in those varieties. In addition, some California growers are working with packinghouses on tree-ripe programs. In such situations, the rock-hard, low-sugar fruit found in many retail outlets is not acceptable. In order to leave the fruit on the tree long enough to develop more sugar, and keep it firm in shipping and storage, these growers are applying ReTain.
Here are some specific benefits in a few key stone fruit cultivars:
Mayglo nectarine. By contributing to larger fruit size, ReTain can increase a crop’s harvest window by 2-3 days. It prevents soft tips and rot both after storage and on the shelf. It also delays softening of nectarine in these time frames, maintaining fruit firmness. Plus, growers see less overripe fruit after storage and on the shelf. All these factors mean improved export quality.
Sunlite nectarine. ReTain improves flesh firmness and decreases over-ripeness, but it also improves the fruit’s background color – a real plus for consumers.
Katarina peach. ReTain increases both harvest and pack out percentages, thanks in great part to improvements in firmness.
Sapphire plum. ReTain improves quality by promoting larger fruit size and increased fruit firmness.
Pioneer plum. ReTain not only maintains fruit firmness, preventing over ripeness and extending storage and shelf life, but because the fruit remain on the tree longer, it also improves the percentages of a crop with the ideal red color.
Larry Anne plum. ReTain provides a number of benefits for this cultivar: increased fruit firmness, increased fruit size, steady brix levels throughout the shelf life, and lower percentages of decay throughout cooled storage and extended shelf times.