Bud to orchard

Hortgro Science puts the spotlight on plant material. By Anna Mouton.

“The quality of plant material has been identified through different initiatives as one of the big failings of our industry,” says Hugh Campbell, general manager at Hortgro Science. He facilitated a strategy session in October last year aimed at resolving some of the issues around plant material. Attendees included technical advisers, researchers, and representatives from nurseries and plant improvement organisations. Fresh Quarterly spoke to Campbell about the five priorities that were identified.

1. Bud-wood parks

The importance of bud-wood quality is self-evident. Poor quality bud wood is more likely to be infected with disease or to deviate from type. The establishment of plantings dedicated to supplying bud wood — so-called bud-wood parks — was highlighted at the strategy session and it was decided to develop best-practice guidelines for bud-wood parks.

One challenge is that clones derived from mutations can revert to the original type. This has prompted the development of a procedure for cutting bud wood in mutations with a risk of reversion, for example some Royal Gala sports.

2. Phytosanitary protocols

“This is part of a process taking place within the technical committee of the Deciduous Fruit Plant Improvement Association,” says Campbell. “There’s an ongoing refinement of testing procedures and technologies. And a specific focus on ensuring the correct viruses and viroids are included.”

According to Campbell, there’s an increasing move toward determining health status based on laboratory testing rather than on visual inspection. He stresses that the source material has to be tested for there to be any guarantee of the health status of nursery trees.

3. Nursery research programme

Hortgro Science has had a work group on rootstock and nursery-tree quality since 2015. The work group includes people with relevant technical expertise. One of its functions is to determine and prioritise plant-material research needs for communication to researchers.

“If we want to have better tree quality at nursery level, then we have to invest in that,” says Campbell. “There’s a lot of applied research done in nurseries which is proprietary. Our job is to fund the more basic work that nurseries won’t be doing.”

4. Handling protocols

“Nurseries are only a part of the chain,” says Campbell. “If growers don’t fulfil their side of the deal, then you’ll have a tree that doesn’t respond as it should.” A need was identified for best-practice guidelines that address the handling of trees from lifting to planting, and Hortgro Science is currently working on the first set of guidelines.

5. Exclusivity of cultivars and rootstocks

Access to cultivars and rootstocks depend on ownership. “From industry’s perspective we would seek to have rootstocks available to all,” says Campbell. “We recognise that we don’t have control over an implementation strategy that would enable all cultivars to be available to any nursery.”

Implementation of the actions identified at the bud-to-orchard strategy session continues. “One of the big complaints from growers has been the quality of trees,” states Campbell, “but in order to be successful, we need to recognise that there are different role players, starting at bud selection all the way through to the planting of the trees.”