The Plum Demonstration Centre – Work Programme for 2020

Work Programme for 2020

The activities and work programme at the centre are discussed with the centre steering group during the winter months. The aims are to demonstrate ‘best practice’ in plum production, ‘best practice’ in crop and environment management and to compare different production techniques. The work programme agreed by the steering group in 2020 continues much of the work begun in 2019 with some new additions and is summarised below.

Rootstock comparisons

The performance of Victoria is being compared on four rootstocks (four replicated 5-tree plots) of varying vigour including VVA1, Wageningen, Wavit and St. Julian A. The planting allows replicated comparisons of the performance of Victoria including tree size/vigour, flowering time, ripening time/season, disease susceptibility, productivity and fruit size and quality.

Training system comparisons

The performance of Victoria is being compared on seven different training systems: Narrow table top, Narrow A frame, Oblique, Super spindle, Fan, Candelabra and Multi-stem.

Variety comparison

A total of 23 new varieties will be planted in Spring 2020 to demonstrate their performance and how the season can be extended from July to October. Three other orchards have also been planted by commercial plum growers in Kent to showcase different plum varieties. These include A. C. Hulme & Sons (early varieties), Highwood Pluckley Ltd (late varieties) and G. H. Dean (varieties with high yield and quality potential).

Protected cropping

An area at the centre has been set up to demonstrate the difference in performance of Victoria grown under polythene clad multi-bay tunnels compared to unprotected Victoria.

Demonstration of mechanical thinning and weed control aids

A number of mechanical aids for thinning flowers and controlling weeds in the crop row are available to growers in the UK. These and other machines will be demonstrated in open events for growers to view their performance. Where available, video demonstrations will be up-loaded to the Plum Demonstration Centre website for viewing.

Demonstrating the use of root-pruning for vigour control

Root pruning will be demonstrated by assessing half a row of root pruned versus half a row without. The effects on tree vigour will be recorded. This work will take place in fan-trained plums in July.

Comparison of fertigation programmes

Fertigation programmes developed by NIAB EMR will be employed at the centre, starting in 2020. In a comparison of two different approaches, half of the trees will be treated with the fertigation programme throughout the growing season and half will be treated only at times during the season when the trees are known to respond to fertigation. A long-term comparison of growth and yields will be made.

Comparision of the use of organic mulches

Many commercial growers now use organic mulches in the tree row to suppress weeds, conserve soil moisture and improve soil texture and soil structure in the root zone. A long-term comparison will be made of trees treated with organic mulch and those not treated.

Earwig-safe spray programmes and conservation biocontrol

Results of AHDB funded research projects on preservation of earwigs in orchards and conservation biocontrol will be implemented in 2020. This will include implementing ‘earwig-safe’ spray programmes, deploying earwig refuges, employing wild flower strips around the centre and between crop rows (in certain areas) and the use of beetle banks. The numbers of earwigs and pollinators will be assessed and recorded. Comparisons of earthworm numbers will also be made between bare soils, grass strips and wildflower areas.