Bounty71 rootstock an update

Transcription

1 Bounty71 rootstock an update Grant Thorp, Andrew Barnett, Kevin Patterson Presentation prepared for ZESPRI R&D meeting June 2013.

2 Bounty71 rootstock an update Bounty71 rootstock has been planted in increasing volumes at trial sites across the country Bounty71 showed promise as a rootstock capable of increasing yield and fruit dry matter of Hort16A in clonal trials at Te Puke Research Centre At the request of the kiwifruit industry, Bounty71 was released before pre-commercial trials had been completed Trials are still in their early stages

3 Bounty71 rootstock an update 1. Previous information Hort16A cropping data ( ) Hayward cropping data ( ) Psa-V monitoring Update a) Fruit yield and quality b) Psa-V monitoring

4 Bounty71 rootstock: released to growers in 2012 With Hort16A in the Bay of Plenty benefits include higher flower numbers, larger fruit with higher dry matter and increased yields What impact has Psa-V had? Hort16A trunks and canopies became infected with Psa-V and were re-grafted to Gold3 in January 2012 Secondary symptoms (exudates/cankers) observed in winter 2012 on Gold3 trunks and leaders (above the graft union) No secondary symptoms observed on Bounty71 trunks (below the graft union) Some primary symptoms (leaf spotting/shoot dieback) observed on shoots allowed to develop from the Bounty71 trunks

5 Bounty71 rootstock with Hayward How does Bounty71 perform with Hayward in the Bay of Plenty? Benefits generally included more flowering and higher dry matter However reduced vigour (less replacement cane growth from the leader zone) could mean less productivity in the longer term Solution may require a change to pruning systems and planting density, but this is yet to be determined

6 Bounty71 in difficult soils How does Bounty71 perform outside the Bay of Plenty? Some evidence that Bounty71 rootstocks growing in heavy, poorly drained soils survive better than Bruno seedling rootstocks However with first crop on Hort16A vines in Kerikeri found more flowers but smaller fruit size, possibly related to reduced vigour (more short terminated shoots and less replacement cane growth) Solution may require a change to pruning systems and planting density, but this is yet to be determined

7 Bounty71 in difficult soils Bruno rootstock Bounty71 rootstock More vigour, delayed cropping compared to Bounty71 Higher yields early, low vigourlack of replacement cane

8 Bounty71 update 2012/13 season Fruit Yield Bay of Plenty No Hort16A vines remaining (re-grafted to Gold3 no crop) Negative effect on Hayward yield - significant bud rot/flower death observed in spring Bud rot also reported on both Hayward and Green14 vines growing at other sites, our data are showing increased incidence of bud rot with Bounty71 rootstock Have not seen similar bud rot symptoms on Hort16A, even under high disease pressure.

9 Fruit per vine Bounty71 Te Puke Hayward yields 'Hayward' 'Bounty 71' Similar result at a second Te Puke trial site Neutral or no effect on quality difficult to establish with crop load differences. Floral loads were similar.

10 Bounty71 Kerikeri Hort16A and Hayward Fruit Yield and Quality Kerikeri Negative effect on Hort16A long term yields Negative effect on Hayward long term yields?... Due to poor replacement cane growth after first main crop Own rooted cuttings best result in terms of yield and quality Bruno slowest to come into production

11 Bounty71 Kerikeri Hort16A data Rootstock Fruit number per vine Fruit fresh weight (g) Fruit dry matter (%) Bounty Hort16A Bruno

12 Bounty71 Kerikeri Hayward data 2013 Rootstock Fruit number per vine Fruit fresh weight (g) Fruit dry matter (%) Bounty Hayward Bruno

13 Bounty71 Gisborne Hort16A and Hayward Fruit Yield and Quality Gisborne Positive effect on Hort16A early yields Positive effect on Hayward early yields However due to poor replacement cane growth during this first cropping season, continued higher yields may not be sustainable in this environment and management system.

14 Bounty71 Gisborne Hort16A data Rootstock Fruit number per bay Fruit fresh weight (g) Fruit dry matter (%) Bounty Hort16A Bruno

15 Bounty71 Gisborne Hayward data Rootstock Fruit number per bay Fruit fresh weight (g) Fruit dry matter (%) Bounty Hayward Bruno

16 Bounty71 and the new varieties? How does Bounty71 perform with Gold3 and Green14? Limited information from replicated trials data from a Kerikeri trial with alternate rows of Bounty71 and Bruno rootstocks Rootstock Cultivar Fruit Fresh weight (g) Fruit dry matter (%) Bounty71 Gold Bruno Gold Bounty71 Green Bruno Green

17 Bounty71 Bay of Plenty Psa-V update 2012/13 Still no reports of secondary infections on Bounty71 rootstock plants (below the graft) Some indication that Gold3 scion cultivar has less Psa-V symptoms. However, this could be an indirect effect of the rootstock - Bounty71 rootstock reducing the vigour of the scion cultivar, and thus these vines required less pruning. December 2012 June 2013 Bruno Bounty71 Bruno Bounty71 Below graft (i.e. rootstock) 0% 0% 0.2% 0% Above graft (i.e. scion) 41% 10% 46% 5%

18 Bounty71 update 2012/13 season SUMMARY Bounty71 vines continue to show high tolerance to Psa-V and also to flooding and water-logged soils Flower bud death issue with Hayward in Bay of Plenty Modified vigour with Hayward in Bay of Plenty Modified vigour with Hort16A and Hayward in Kerikeri and Gisborne vigour too low? Less vigour possibly means less Psa infection Insufficient data with Gold3 and Green14 at present

19 Bounty71 update 2012/13 season As with all rootstocks an appropriate scion-rootstock-soil type combination needs to be determined Data suggests Bounty71 will not be the best rootstock for all scions, all soil types and all regions Proceed with caution, we will keep you informed as more data comes to hand Scion cultivar Rootstock cultivar Soil Environment