Precision case study

Case study – Wisbech Contract Farming

Cambridgeshire-based top fruit grower John Portass hosted some of Agrovista Precision’s development work last season and is impressed by what he has seen.

“I think there is massive potential for this type of technology, particularly in conjunction with modern orchard systems that lend themselves to this type of image sensing,” he says.

“Precision farming technology is still in its infancy in the fruit sector, but I can see it playing an increasingly important part in our decision making.”

Mr Portass is managing director of Wisbech Contract Farming, an innovative family-run fruit business with 100ha of apple and pear orchards.

In recent years he has been fine tuning management to maximise the percentage of top-quality fruit to meet the demands of leading retailers.

2D planting

Target yield for his 50ha of Gala is 60t/ha, mostly grown on post and wire system. Three years ago he took things a step further and planted 7ha of Gala on a 2D narrow fruiting wall system, with a target yield of 80t/ha.

Planted at 1m centres, each tree is no wider than 40-50cm at the bottom and 30-50cm at the top.

“The system uses multi-leader trees with lots of stems and spur wood,” says Mr Portass. “Essentially we are taking shading away, and nothing is hidden.”

The 2D orchards can be mechanically pruned, and Mr Portass also hopes it will eventually enable mechanical harvesting.

This type of planting system also appears ideally suited to drone imaging, which could be particularly useful in developing the farm’s already highly effective blossom thinning programme.

In recent years judicious pruning coupled with carefully targeted ammonium thiosulphate applications have reduced the need for chemical fruitlet thinning and have almost eliminated the need for hand-thinning, halving overall thinning costs.

“We were aiming for one and two fruits per cluster, but as demand for smaller fruits has increased, we are now looking for one to three to achieve an average fruit diameter of 66-67mm,” says Mr Portass.

“Agrovista’s blossom counting service could help us to set up fruit load even more accurately earlier in the season.

“We also know that brix levels and fruit texture can suffer if fruit is grown in bunches. It’s even more important that we achieve good pruning and accurate blossom thinning, together with fruitlet thinning if required, to create the correct leaf to fruit ratio to stop that happening.”

Accurate information

Mr Portass believes modern fruit wall designs will suit precision technology. Their narrow structure is ideal for filming and should provide very accurate information.

“At the moment we are assessing blossom load by walking orchards and assessing a representative sample of trees, perhaps 20-30/ha, which is pretty labour intensive.”

Overall, the trial results were pretty good last season. There was one area of discrepancy, but this was in an old orchard approaching the end of its peak.

“In three to four years maybe 50% of the farm will be under a 2D system or similar,” says Mr Portass. “I think flying a drone on these or similar fruit wall systems could produce very accurate results, which will be much quicker, more accurate and will save money.”

Improving uniformity

The ability to assess tree vigour accurately and quickly could be a very useful tool to fine tune inputs and improve orchard uniformity, Mr Portass believes.

“We don’t use much plant growth regulator these days. Most have been withdrawn for the market and those that are available are not the best in terms of activity.

“We rely more on fertiliser, irrigation and fertigation to manipulate tree vigour, and mapping could really help us manipulate inputs more effectively in the following season.”

Lack of vigour can also be a problem. “We have been doing a lot of work on soils through Agrovista’s Soil Health service. Overlaying various soil maps onto the vigour maps can help you pinpoint any underlying problems, such as soil type, topography, pH, waterlogging or some nutritional cause.”

Mr Portass has been using several products to good effect, including LCF Boost that feeds soil microbes and fungi, Phosphorus Liberator that dissolves locked-up phosphorus and makes it available to plants and Liquid Gyspum, a soil conditioner that improves workability, drainage and root exploration.

“Using vigour mapping and soil mapping has real potential to help us produce more consistent orchards,” he says. “The more information you can extract, the better the plan you can come up with.”

Spraying technology

For now, Mr Portass is happy using the blossom and vigour maps as an aid to manual application, but will consider adopting variable rate spraying technology when the business upgrades its sprayer.

“I think this would benefit blossom thinning in particular. At the moment we would use the drone imagery as a guide, printing it off and using it to manually vary spray volumes.

“But as we use these tools more and more, the potential payback will increase, so there will be more justification for investing in precision application.”