EFFECTIVE stone and clod separation is the first and key step in the premium potato growing strategy for Cornish farmer/contractor Andrew White.

But, in common with other potato producers, he is always striving to find ways to improve seedbed quality while lifting outputs from this painfully slow process. The recent addition of a new Grimme CS 150 ROTA Power into the fleet, he feels, not only offers faster work rates but it also leaves an improved seedbed when working in a wide range of soil types.

Andrew's family business, based near Bodmin, is involved in all the work on 520ha of the crop, from land preparation and planting right through to lifting and grading.

"We rely on just a few key people - myself, sons Kevin and Mark and two other staff. With such a small workforce we are always looking for new machinery to improve efficiency and reduce our operating costs," explains Andrew. "From our experience so far this spring I now think two of these CS 150 ROTAPowers could carry out the work of three others."

He bought the machine after being impressed by a demonstration last year. "The adjustable star system is a very important advance. Not having to change webs or stars saves an enormous amount of time. It means we can also adjust the settings in work to create exactly the seedbed we need, regardless of conditions," says Andrew.

Mark, who has worked the machine on about 160ha this season, continues: "Swapping over webs and sprockets on a normal machine can take up to half a day or longer - up to two days on a fixed star machine. Now we don't have to do that, I simply adjust the star settings on the move."

He also notices the benefit of the narrower, shorter machine when working on slopes. This is increasingly important because as the business expands there is always a need for fresh ground, which means equipment is being asked to work more marginal land, which was previously considered too stony or steep to plant.

"The adjustable stars on the Grimme CS 150 ROTAPower allow me to go across hills that previously we could only go up or down using a web-based machine. This is because it retains the soil, which doesn't roll back down - as it does on the webs," he explains.

His brother Kevin, who follows with the planter, also notices a marked improvement in the bed left behind the Grimme CS 150 ROTAPower de-stoner. "It leaves a higher and narrower bed, which means there is more soil for planting into and it's easier to work on sidling ground. Also the soil doesn't fall down the sides it stays in the bed and doesn't run into the wheelings," he adds.

In the first few months of operation the family are also impressed by the relatively low wear rates. "I was, at first, a bit worried about the possibility of high wear on the front row of stars," explains Mark. "But the ROTA Power front rotor takes all the wear from the front stars and we are pleased with how well it is lasting. The actual wear is very low so far," adds Kevin.

He also points out the machine has never broken down. Admittedly it was new this season. But he, stresses, it is fairly unusual not to suffer any stoppages - actually it is virtually unheard of with a de-stoner!