Getting the most from your potato harvesting machinery

With the introduction of more efficient separation systems, modern potato harvesters can lift up to 60/t an hour. However, care needs to be taken to prevent bruising the crop during harvesting

Although modern potato harvesters are both speedy and efficient, careful work can really pay dividends, says Barry Baker of Grimme UK Ltd. At harvesting, two factors are of paramount importance: getting the crop out of the ground and minimising tuber damage. “It is important that harvester and trailer operators work together as a team,” says Mr Baker, who has worked in the industry for more than 40 years.

“If problems arise, they need to investigate what is going on and rectify the situation. “It’s crucial the harvester driver knows the quality standards needed and whether they are being achieved. Good communications are essential between the driver, the trailer operator, the service engineer and the QC room, so adjustments can be made accordingly.”  

Damage and bruising can be caused by crop, tuber or harvester factors. Tubers should be checked for damage levels at least once every 24 hours, looking out for skinning, cracks, cuts and gouges, and where possible, using a wash barrel and a bruising hot-box. “Ideally, prior to starting lifting, it’s a good idea to assess bruising and damage susceptibility by taking samples.”

Bruising susceptibility is not fixed, and it changes over time within each crop and within each field. It can be worth considering irrigating the fields immediately before harvesting to encourage soil retention up the primary web, to help cushion the tubers. “In dry soil conditions, tuber damage can be caused by rollback on the webs, or during transfer. If you are harvesting when the soil is dry, try to run the harvester full of crop so that at transfers tubers fall and cushion each other, so they avoid bouncing around and rolling back.  

“You should also consider reversing haulm rollers or changing to softer material and slowing down the roller rotational speed.” He suggests removing 70-80 per cent of haulm on primary extraction rollers and on the secondary web aiming for 80-85 per cent fill rate, which will be governed by tuber yield and web speed. “Tuber damage is a one-way process and once it is done it cannot be undone, so prevention is crucial.”   

Crucial areas for careful attention
Topper height
The first is to ensure the topper height is set correctly, so the haulm is chopped without damaging the crop in the rows. Thanks to the introduction of shaping hoods on planters the row profiles have changed so it is very important that the flail configuration is also adjusted to suit the row profile.

Tractor wheel
The tractor wheel equipment and setting is important to help avoid compacting the sides of rows which then create clod and increase the work the harvester has to do, therefore burning more fuel.

All modern trailed harvesters have the facility to adjust the drawbar height to allow the machine chassis to work parallel to the ground which aids feed into the front of the machine.

At the front end it is also critical to make sure that the diablos are set to the row profile so the shoulder of the diablo is hugging the side of the row. I advise fine-tuning of share height and pitch adjustment to ensure a clean feed onto the web as if it is set too low bruising can occur when the potatoes are fed into the web. 

Disc width and depth
Other important considerations include intake disc width and depth If the discs are working too deeply then this can carry the whole front end and restrict the working depth of the share.

Haulm rollers
When setting haulm rollers it is important not to have them set too aggressively as this is one of the most highly potential areas for damage on the machine. Haulm deflector fingers must also be set in the least aggressive position possible.

Separator systems
With modern separator systems, the longer the crop is on the separator the higher possibility of damage. It is important, therefore, to try and keep the cleaning systems full without the crop bouncing. 

Health and Safety
All staff must be properly trained and they must follow health and safety procedures.
Monitor crop Crops should be monitored at regular intervals and also regular hot box testing done as the crop is placed into store.