Fruit farm manager Rose was speaking at BIFGA's technical day in Kent on 15 January.
He said it had been proved by an HDC-funded champion-picker project that he carried out with human behaviour and performance specialist Kathy Strong.
They developed an apple-picking model based on a study of the very best pickers so that their modus operandi could be passed on to less-skilful pickers.
Rose said: "If we can lift the performance of the lower performers by 10, 20 or 30 per cent it will make a significant difference to a business's success. But if you go for speed (of picking) alone, fruit quality can be sacrificed. Our champions delivered both.
"There's a massive variation in picking standards. The cost that growers have to bear if they don't train their pickers (for improved performance) is too much fruit on the ground and left on the trees (and excessive fruit bruising) - and you don't have to go far to find pickers who do these things."
To produce their picking model, Rose and Strong identified "champions" and worked out how they picked and what kept them going. According to Rose, the champions were unable to say why they excelled, "so it took us a while to find out".
He said that although champions need to be fit and healthy - good fitness helped them last the pace without tiring - they did not necessarily have to be athletes. They also required excellent hand-eye co-ordination - which can be taught, but it takes time.
"Champions seem to naturally pick in the best way to get the fruit off easily, and they work in a well-organised way," he added. "They're thinking all the time, 'reading' the tree and deciding on the best way to pick it. They are fully focused and pick well on 'automatic pilot'.
"They don't talk (while picking), have targets they reach and prefer to work alone. They also have a positive outlook with no negative, counter-productive thoughts."
Having created their picking model, Rose and Strong tested it and found that it worked well - although in one case the improvement in picking performance was not sustained because the supervisor involved did not believe in it. The opposite was true in another case, however, due to better supervision. As a result of this experience, Rose and Strong are undertaking a project to produce a "champion supervisor" model.
"Although it helps, you don't have to be a champion picker to be a champion supervisor," Rose said. "Many other qualities are required, including a very good understanding the operation."