New-gen rootstocks deliver earlier and more productionIndustry Best Practice
- Rootstock trial under commercial conditions enables more robust local evaluation
- First in-orchard scale trial of G202 and JM rootstocks under local conditions
- New generation G202, JM1 and JM7 achieving yield advantage over the earlier generation M26
Alvina Gala trees on the Cornell-Geneva rootstock G202 are out-yielding their counterparts on M26 by 25 per cent in one of the first commercial plantings of the US CG series and Japanese JM series rootstocks in Australian conditions at Jeftomson Orchards in Victoria’s Goulburn Valley.
In their second crop, four years after planting in 2017, the Gala on G202 is producing 50t/ha and those on the M26 40t/ha.
Trees on the Japanese rootstock JM1 in the same block are producing similarly good results.
Jeftomson General Orchard Manager Brent Reeves said the G202 trees had outperformed from the start and he expected them to maintain their productivity edge.
“I said in 2017 this will be my preferred rootstock, and I’m now trying to plant G202 or JM1 as my preferred rootstocks.
“We have a program of planting 50,000 trees a year. Out of those, next year we will probably do zero G202 as they are not available, but in 2022 maybe 20,000 of those will be G202.”
Brent took the opportunity to trial a range of rootstocks when replanting a block of Gala lost to waterlogging after the wet 2016—17 year.
“It was a very wet year and half the trees in a block of Gala on M26 died,” he said. “The whole block was pulled out in May and replanted in September 2017.
“When I ordered the trees, I was looking for a replant decline-resistant rootstock and Brendon (Tahune Fields nursery) had the G202 available and said why don’t you try these.”
As well as the M26 and G202, Brendon also suggested that Brent include JM1, JM7 and Pillitzner Supporter 4 to assess their performance.
Originally planted as central leader, the block was reworked into a V-trellis at 4.8m x 1.20 with approx. 3500 trees per ha.
Four years on the trees on the G202 are clearly showing better canopy development and filling the space.
“The G202 trees grew better from the start,” Brent said. “The M26 trees are a lot smaller and haven’t grown as well. It’s possible we should have left them for another year. This year there might have 100 fruit/tree (50t/ha) on the G202 trees. There are 80/tree (40t/ha) on the M26 and next year the M26 trees are going to have only 80 fruit again but the G202 will only go up.
“M26 might eventually get there, but G202 got their earlier and delivers more production.”
Brent said the JM1 trees had performed very similarly to the G202, with the JM7 showing more vigour and less crop. The Supporter 4 had produced a similar crop to the M26 trees.
Although the second-most widely planted rootstock in New Zealand, and available via ANFIC nurseries since at least 2014, G202 has been slow to take off in Australia, despite providing woolly apple aphid (WAA) resistance as well as less susceptibility to apple replant disease (ARD)..
APAL Variety Development Manager, and former Australian Pome Fruit Improvement Program operations manager, Tom Frankcomb said the Jeftomson trial showed the value a rootstock could add in increased productivity and the importance of rootstock selection.
Tom said although royalties had to be paid on the next generation rootstocks, an extra 10t/ha more than compensated for the additional outlay and over the lifetime of the tree would amply reward the small additional cost.
A key focus of the new Future Orchards® program, when it comes under APAL management later this year, will be regional trials and/or demonstration blocks, including rootstocks, to give growers access to local evaluation.
Tom said APAL plans to have trials and/or demonstrations in all regions by 2022—23 and the CG and JM rootstocks, which also provide some WAA resistance, would be among those being demonstrated.
“The opportunity that next generation rootstocks offer to improve productivity and profitability in new orchard plantings can be clearly seen from this simple in-orchard comparison,” Tom said.
“A lack of broader regional trials has meant few growers have had the opportunity to see results like this for themselves and the uptake and adoption by industry has been slow.
“We need that information out there to inform that future thinking and direction and now that APAL is funding the program we will be prioritising variety and rootstock trials.”
An exposé on pome fruit rootstocks (Apr 2017)
Tasmanian Apple Replant Disorder rootstock trial update (Sophie Folder, Mar 2021)
Cornell Geneva series rootstocks are available through ANFIC nurseries and JM rootstocks through APFIP-accredited nurseries. Contact Tom Frankcomb for more information on firstname.lastname@example.org