Difficulty finding enough labour to harvest crops is a problem that many strawberry growers are experiencing this season.
For this reason, a number of growers will be looking to find ways of improving their picking rates. One method they may consider is the use of picking rigs, which have been on the market for a couple of years but are still used by a relatively small number of growers.
Those farms that are employing strawberry picking rigs are finding their picking rates improved by 20 to 30 per cent - but, as the experiences of three farms show, it takes time to adjust.
Last year, three farms - Simon Clarke's Manor Farm in Hints, Staffordshire; Stephen McGuffie's New Farm in Elmhurst, Staffordshire; and Ross Mitchell's Castleton Farm in Laurencekirk, Kincardinshire - used models by Viking and Haygrove, and found much common ground between them.
Each farm experienced significantly improved picking rates and they all plan to continue using rigs.
However, the farms found that it is never a smooth transition from manual to rig picking, but planning ahead - and learning from others - can prevent any serious mistakes from happening.
Clarke says: "Don't expect great results in the first fortnight, (but) the staff improves rapidly thereafter."
The farms found that average or below-average manual picking-rate staff members are best suited to rigs.
These below-average pickers have, until now, increased the overall piece rate by affecting the average kg/hour rate - thereby increasing the pounds /kg paid. Improving their performance consequently reduces the amount paid.
The staff also enjoyed working on the rigs, with all the farms reporting problems (of unhappy staff) when they moved people back from rigs to manual.
Rigs, however, will never completely replace manual picking because it is not sensible to rig-pick all crops all of the time. But rig-picking is likely to steadily erode the percentage of manual pickers used as farms refine the possible benefits of using rigs.
Better, more confident decisions are being made as farms collect more performance data on crop type and rig performance. And the picking rate may not be the only criteria to use a rig. They can be used to cover comparatively large areas that need to be covered - at both ends of the season.
Effects on farm staff
Staff selection was found to be particularly decisive for success. Growers should not necessarily look for those people who are attracted to machinery.
Some growers, including Mitchell, see rigs an important way of retaining staff - maybe even a recruitment advantage. Their staff's better productivity has been found to reduce growers' concerns of earning less when crops are thin towards the ends of the season.
Better staff retention saves on staff training, sourcing and administration. Rig-picking also requires considerably less physical effort for staff because no carrying of trays is required.
Communication on the rig is important, and having a single language does help. One farm is considering banning personal stereos so staff can hear each other - and the driver - better. However, rig music from a car stereo can help reduce the monotony of the job.
There is a risk of the driver and crew becoming "switched off" over time. Good drivers can, and will, move on to other things as the job eventually loses its challenge for them.
Team players are really needed to make the system work. The driver (rigs are pretty much self-steering) is the most important member of the team, so growers need to think carefully about whom to give this role.
It was found that drivers will select the best manual pickers if given the choice. While rigs improve the performance of below-average pickers, they also improve the best pickers. Unfortunately, such workers are in short supply.
McGuffie found that his top 10 pickers still did 30 per cent better on rigs compared to other crews - so these star manual pickers will still earn more than being on a rig with below-average colleagues.
Staff rose to the challenge of being selected for rig-picking in most cases. About 10 per cent may wish to remain manual for social reasons. They also need to have suitable physical dimensions to work comfortably on a rig. Cohesion is important for the crew - a relatively slow picker is soon spurned.
Having a couple of rigs on a farm certainly creates a level of rivalry between crews, which can improve their performance. Crops can be more cleanly picked by rigs as the driver can nip off the slow-moving rig and check beds behind the staff as needed.
Converting your farm to rigs
Replacing manually picked tonnage with rig picking takes time. The optimum rate will be achieved several years after first investing in a rig. Points to remember when making the investment include:
- try to get your rigs delivered early in the season to allow plenty of time for training and to smooth out "wrinkles";
- short-term improvements include identifying the best number of plants per metre and ensuring that you have a sufficient number of workers to use the rigs effectively - also try to improve your turning circle on headlands;
- medium-term improvements include improving your field construction so that it is more suited to the rigs, such as reducing canopy sizes and possibly planting at a lower density for a cheaper pick.
Rigs present new challenges on planting patterns. All farms can find a rig configuration to suit their existing crops and tunnels - but getting the most out of rigs will mean adjusting future planting and tunnel specifications. The three farms that took part in this trial of rigs concluded that:
- longer bed runs are possible, although cross-paths are still needed for some manual picking and ventilation, especially on the brows of ridges;
- growers should build more uniformity into the field, including uniform bed and path widths, and uniform bed heights;
- growers should also avoid overly high beds, especially planting on their shoulders - the staff cannot reach very low hanging berries;
- wet zones should also be avoided, as rigs will sink and cause damage - there will be implications on tunnel run-off and its drainage;
- growers should allow sufficient headland for turnaround. Confined spaces slow down turnaround, which can take up a significant proportion of time if they have short rows as well.
Performance is highly variable between crops as farms have a range of picking densities (berries per bed-metre) and experience of managing crews.
Mitchell reckons to have averaged 15kg/hour across all crops in 2007, the rate varying from 14 to 20kg/hour.
These factors seem more decisive than the rig itself. All three farms have rig-picked for no more than two years so there is likely to be room for further gains. Average improvements noted across these three farms for 2007 are shown in the table (left).
Picking rig manufacturers
There is now a good choice of rig designs and prices. All three farms involved in these trials have been pleased with their rigs and gained similar improvements in productivity.
Manufacturers include Haygrove Tunnels and Viking Tunnels.
Robert Irving would like to thank the three growers for their generous contribution to this article and their willingness to share their experiences. Clarke, McGuffie and Mitchell used Haygrove Series 5 & 8 and the Viking (Commander and Warrior models) respectively.
WHEN TO MANUAL-PICK
- When a field has short rows, manual picking is preferable because rig downtime at turnaround (turning the machine around) affects picking rate
- When crops are ripening unevenly across a tunnel - such as when a fleece has been misplaced
- Glut (very heavy) crops are often better-picked manually
WHEN TO RIG-PICK
- If a crop has a high percentage of small berries
- If a crop has poorly displayed berries
- If a crop has unevenly-sized plants
- When there is a staff shortage