Regulex 10 SG was targeted at Apple growers to help them meet the "ever increasing focus on quality and visual appeal", said its maker Interfarm (UK).
The product involved the combined activity of two gibberellins, GA4 and GA7, to improved consistency and reliability.
"Regulex improves fruit finish and reduces russets on Coxes and many other apple varieties such as Golden Delicious and Gala, said technical manager Dr David Stormonth.
"It has been shown to increase fruit size and improve fruit shape, leading to better overall fruit quality and marketability.
"Regulex normalises the development of the epidermal cells and stimulates an even build up of the fruit's cuticle. The GA4-GA7 combination increases cell elasticity, so fewer cracks appear."
Apples resisted problems of surface tension during periods of rapid growth. The product also increased the number of larger-size fruits by stimulating cell division and cell elongation.
"The improved formulation provides the ideal ratio of naturally-occurring gibberellins, he said of Regulex, which dissolves instantly in water and is distributed by HL Hutchinson and UAP.
It is applied 20 to 40 gms/ha at seven-day intervals or 25 to50 gms/ha at 10 day intervals. Higher rates should be used when conditions are conducive to russeting, such as cool, wet or windy weather.