1. Update on the Performance of two Southern Highbush Blueberry Cultivars Grafted onto Vaccinium arboreum (Sparkleberry) Rootstocks
Bruno Casamali
MS Student
Rebecca Darnell and Jeff Williamson
Horticultural Sciences Department
IFAS, University of Florida

2. Vaccinium arboreum (Sparkleberry)
Native to the southeastern U.S.
Shrub or small tree – Single trunk
Deep root system – drought tolerant
Tolerates soil pH up to 6.5
Sand or sand-clay soils
Low organic matter
Low Fe and NH4
cas.vanderbilt.edu

3. Objective
Evaluate plant growth, yield, average berry weight, and berry quality of grafted and own-rooted blueberry plants in amended and non-amended soil.

4. Straughn Farms, Archer
UF PSREU, Citra
Experimental sites

5. Material and Methods Own-rooted ‘Farthing’
‘Farthing’ grafted onto V. arboreum
Own-rooted ‘Meadowlark’
‘Meadowlark’ grafted onto V. arboreum

6. Soil treatments Arredondo sand soil, with low organic matter, pH ~ 6.0
Pine bark amended soil
Non-amended soil
Soil pH kept between 5.0 – 6.3

7. Graft union

8. Grafted ‘Meadowlark’, 2013 – Citra, FL

9. ‘Farthing’ canopy volume - Citra
Canopy volume (m3)
Treatment
2012
2013
2014
2015
2016
Own-rooted / amended
0.06 a
0.8
0.9
1.14
1.29a
Own-rooted / non-amended
0.03 b
0.5
0.6
0.86
0.88b
Grafted / amended
0.3
1.02 ab
1.09ab
Grafted /
non-amended
0.4
0.93
0.97ab

10. ‘Meadowlark’ canopy volume - Citra
Canopy volume (m3)
Treatment
2012
2013
2014
2015
2016
Own-rooted / amended
0.09 a
0.7
1.0
1.45 b
2.19a
Own-rooted / non-amended
0.04
0.4
0.6
0.99 c
1.33b
Grafted / amended
0.02
0.5
1.1
1.95
2.41a
Grafted /
non-amended
1.62 ab
2.25a

11. ‘Farthing’ canopy volume - Archer
Canopy volume (m3)
Treatment
2013
2014
2015
2016
Own-rooted / amended
0.8 a
1.0
1.3a
Own-rooted / non-amended
0.4 b
0.5 c
0.6
0.7b
Grafted / amended
Grafted /
non-amended
1.0ab

12. ‘Meadowlark’ canopy volume - Archer
Canopy volume (m3)
Treatment
2013
2014
2015
2016
Own-rooted / amended
0.9 a
1.2
1.1
1.4a
Own-rooted / non-amended
0.4 b
0.5 c
0.6b
Grafted / amended
1.5a
Grafted /
non-amended
0.8

13. Own-rooted ‘Meadowlark’
Non-amended soil, Archer, pH 5.97 (Nov. 8, 2013)
Grafted ‘Meadowlark’
Own-rooted ‘Meadowlark’

14. Meadowlark own-rooted (front) and grafted (back) on non-amended soil without acid injection, Archer.

15. Meadowlark – own-rooted, non-amend., Citra Nov. 23, 2016.

16. Meadowlark – grafted, non-amend., Citra, Nov. 23, 2016

17. Meadowlark – grafted, amended, Citra, Nov. 23, 2016.

18. Total yield - Citra Total yield (g/plant) Treatment Farthing
Meadowlark
2013
Own-rooted/amended
4731 a
2789
Own-rooted/non-amended
2222 b
1451
Grafted/amended
1954
1955
Grafted/non-amended
1933
1759
2014
4837
4052 ab
4008
2710
4114
4468
3484
3722

19. Total yield - Citra Total yield (g/plant) Treatment Farthing
Meadowlark
2015
Own-rooted/amended
4092 a
5801
Own-rooted/non-amended
3356
3073 b
Grafted/amended
3541
7016
Grafted/non-amended
2928
5947
2016
3850
2671
671 c
1603
6788
6936
4758
4919

20. Total yield – Archer
Total yield (g/plant)
Treatment
Farthing
Meadowlark
2013
Own-rooted/amended
5192 a
3323
Own-rooted/non-amended
1980 b
1418
Grafted/amended
2568
1281
Grafted/non-amended
2009
1679
2014
4943
5036
1927 c
1715
4298 ab
2792 bc
3263
- In Archer, irrigation water has high levels of Ca and HCO3-
- High soil pH between Feb to Jul 2013
Canopy volume and yield are highly correlated
R2=0.69 in 2013 and R2=0.51 in 2014
Plant architecture in ‘Farthing’ and greater fruit set in ‘Meadowlark’

21. Total yield – Archer
Total yield (g/plant)
Treatment
Farthing
Meadowlark
2015
Own-rooted/amended
5090 a
5369
Own-rooted/non-amended
2433 b
1757 c
Grafted/amended
4842
4226 ab
Grafted/non-amended
3996
3771
2016
6101
6976
3903
4570
7347
7567
5937
6843
- In Archer, irrigation water has high levels of Ca and HCO3-
- High soil pH between Feb to Jul 2013
Canopy volume and yield are highly correlated
R2=0.69 in 2013 and R2=0.51 in 2014
Plant architecture in ‘Farthing’ and greater fruit set in ‘Meadowlark’

22. ‘Meadowlark’ seasonal berry weight- Citra
Berry weight (g)
Treatment
2013
2014
2015
2016
Own-rooted / amended
2.34 ab
1.79 b
2.03
1.75b
Own-rooted / non-amended
2.40
2.12 a
1.64b
Grafted / amended
2.60
2.25
2.37
2.18a
Grafted /
non-amended
2.51
2.21
2.33
2.29a

23. ‘Meadowlark’ seasonal berry weight- Archer
Berry weight (g)
Treatment
2013
2014
2015
2016
Own-rooted / amended
2.22 b
1.77 c
2.12 a
1.72b
Own-rooted / non-amended
1.66
1.52 d
1.94
1.76b
Grafted / amended
2.53
2.35
2.14a
Grafted /
non-amended
2.36 ab
2.06
2.17
2.18a

24. ‘Farthing’ seasonal berry weight- Citra
Berry weight (g)
Treatment
2013
2014
2015
2016
Own-rooted / amended
2.33 a
1.95
1.91
2.08ab
Own-rooted / non-amended
2.28
1.84
2.18
1.87b
Grafted / amended
2.27
2.05
2.00
2.18a
Grafted /
non-amended
2.02
2.16
2.27a

25. ‘Farthing’ seasonal berry weight- Archer
Berry weight (g)
Treatment
2013
2014
2015
2016
Own-rooted / amended
1.73 a
2.00 b
2.11
2.26a
Own-rooted / non-amended
1.46
1.76 c
2.20
2.00a
Grafted / amended
1.74
2.22
2.08
2.37a
Grafted /
non-amended
1.79
2.24
2.16
2.22a

26. Bacterial leaf scorch (Xylella) symptoms on own-rooted Meadowlark, Citra, Nov. 23, 2016

27. Bacterial leaf scorch (Xylella) symptoms on grafted Meadowlark, Citra, Nov. 23, 2016

28. Conclusions
Grafting SHB on V. arboreum rootstocks delay plant growth and yield.
After the lag phase, grafted plants were larger than own- rooted plants on non-amended soil, and similar or larger than own-rooted plants on amended soil
Initially, yields were reduced by grafting. However, grafted plants had comparable or higher yields than own-rooted plants in years 4 and 5.
Mean berry weight of grafted plants was generally greater than own-rooted plants.
Grafted Meadowlark plants were less affected by blueberry leaf scorch (Xylella) than own-rooted plants during the first 5 years after planting.

29. Acknowledgments Florida Department of Agriculture
and Consumer Services
National Institute of Food and Agriculture
USDA, SCRI

30. Thank you! Questions?