Archive Article: 1997/08/02

2 August 1997




A Yorkshire potato business has used the same make of harvester for 28 years. Alan Swaby finds out how the very latest model is shaping up.

ITS early days yet but already John Scholes has stepped up his harvest work rate and reduced the number of staff needed to keep the new Grimme GZ1700 working.

With 28 years of experience with Grimme harvesters, its little wonder the John Scholes Potatoes business was given an early option on the radically-different GZ1700 when it started to roll off the production line.

"I was able to see this machine last autumn when Grimme trialled it on my property, I then followed it to other farms in this area," says Mr Scholes, who admits to not being mechanically-minded, but believes that experience allows him to judge whether something looks right or not.

"We had a good look at the GZ on both light and heavy soils before finally buying the machine at Smithfield. My feeling is that this will be a wonderful machine – much better than earlier models."

From their base at Nab House, about 10 miles north of Driffield in the Yorkshire Wolds, heavy soils are something the Scholes family – John, his son Richard, and daughter Rachel – know all about.

"Most of the land is medium loam over chalk which really holds in moisture – which is just as well as we have irrigation on only 150 of our 750 acres of potatoes," says Mr Scholes.

However, heavy levels of rain during July meant about 20cm (8in) fell in one four-week period, with around 6.4cm (2.5in) over the six days before potato harvesting started.

"If ever you wanted to see how a harvester was going to shape up in heavy soil, this was the time to do it."

Mr Scholes decided not to go for the hydraulic wheel option on his £44,000 harvester. This option is aimed at users with heavy soils, but Grimme claims that the tractor wheel slip is reduced in any case by a pick-up hitch towing connection, which means the harvesters weight is transferred to the point closest to the tractors rear axle to aid traction.

"The GZ1700 is surprisingly light, and we havent missed power drive at all, even though weve been working some particularly wet fields," Mr Scholes points out.

Previously, the 850ha (2,100 acres) Scholes enterprise worked three Grimme All-Rounder harvesters – two of which have been held in reserve and for spares.

In Mr Scholes opinion, the GZ1700 scores over its predecessors in its work rate and ability to tackle heavy ground. He estimates the GZ is doing about one-and-a-half times the work load of an All-Rounder. Ware crop yields vary from 37-74t/ha (15-30t/acre).

Better still, he is able to reduce the mind-numbingly boring work of stripping trash from the harvester. "We used to need four workers on the All-Rounder. But so far, in the worst conditions, weve only had two on the new GZ. Where the soil is not so heavy, we havent bothered putting on any."

The single web design means that conventional haulm removing rollers, normally situated between the main and secondary web on harvesters, are not used. Instead, harvested material passes from the main web – adjustable from the tractor cab to create a soil-removing wave effect – to a haulm separator using polyurethane and rubber rollers.

Topping needed

This year the Scholes have found no need to do any topping at all, although it may become necessary if the haulm gets too heavy on the King Edward, Desiree, Squire, Maris Bard, Marfona, Cara and Nadine grown at Nab House.

The full width, haulm removal gear has been very impressive in removing the tops without experiencing any build-up or blockage in the stripping mechanism – or in the separator mechanisms.

After the haulm separator comes a new design of clod separator which avoids the usual violent changes of direction which can cause tuber damage as they hit the separating rollers. Four rows of plastic stars, each with a solid clod roller, remove clods, small stones and any remaining haulm or weeds.

Although the new wave belt and separators may protect the tubers even more than before, Mr Scholes says he will be happy to maintain the 9% fault level reached in recent years with earlier models – especially since damage levels can climb to 30% on some other harvesters.

Setting up the machine has meant calling in Grimme engineers to work on the separators and the star selections. However, it is difficult to get Mr Scholes to say a bad word about the GZ1700.

"Grimmes policy is to have spares readily available and as far as I can tell they are as competitive as the others on servicing. No, I am sorry. I cant think of a damn thing wrong with this machine."


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