Old man saltbush is a key species for grazing systems in dry areas of Australia. Researchers screened over 80,000 saltbush plants from 27 locations to develop superior cultivars. They identified significant variation in traits like biomass and palatability. Based on multi-year trials of over 20,000 plants, they selected elite clones and are developing seed cultivars to improve establishment and reduce costs for farmers. The new cultivars show promise to boost the resilience and productivity of grazing lands across southern Australia.

1. Old man Saltbush Improvement
p
Presented
by
Ram Nair

2. Background
Southern Australia’s agricultural regions are
experiencing a growing trend of variable rainfall and
increasing risk of crop failure particularly in the more
vulnerable marginal areas.
Most
M t common strategic response t managing climate
t t i to i li t
variability in lower rainfall cropping areas is
diversification and maintaining a healthy emphasis
on livestock enterprises.
Increasing prominence of livestock industries creates
gp
opportunities for shrub forage species.
Old man Saltbush (Atriplex nummularia) is a key
species in productive and resilient grazing systems
based on perennials.

3. Cultivar Development
Development of clonal cultivar
OMS is native to Australia and grows naturally in harsh, arid areas. Seed
was collected from 600 plants at 27 localities (provenances) around
Australia. Comprehensive germplasm collections of OMS were established
in SA (Monarto), Condobolin (NSW) and Tammin (WA). - 20,000 plants at
each site. Sequential selection was conducted for key traits and elite
site
plants identified for clonal evaluation trials.
Development of seed cultivar
Suitable male and female plants identified from the in-situ collections will
be utilised for this.

4. Over 80 000 plants screened at 4 locations
p
2 subspecies
Originating from 27 sites

5. Methodology
Assessment of variability in:
productivity – edible biomass (Adelaide method)
animal preference (sheep grazing)
i l f ( h i )
re-growth after grazing
Nutritive value

6. Saltbush evaluation site at Monarto, SA

7. Saltbush evaluation site at Condobolin, NSW

8. Saltbush evaluation site at Tammin, NSW

9. Results:
Significant variation was observed for edible biomass.
Heritability for dibl bi
H it bilit f edible biomass: 0.15 to 0.21
0 15 t 0 21

10. What do the animals have to say?

11. Grazing plan at Monarto, SA
Monarto
25 /ha; 1.8 ha; therefore 45 sheep
( Low (rep 1)
( High (rep 1) 50 /ha; 1.8 ha; therefore 90 sheep
( Low (rep 2)
25 /ha; 1.8 ha; therefore 45 sheep
( High (rep 2) 50 /ha; 0.9 ha; therefore 45sheep
Pre-conditioning paddocks

12. Grazing preference scoring
Score 1 Score 2 Score 3
Score 4 Score 5

13. Saltbush evaluation site at Monarto, SA
- grazing preference by sheep

14. Saltbush evaluation site at Condobolin, NSW
- grazing preference by sheep

15. Saltbush evaluation site at Tammin, NSW
- grazing preference by sheep

16. Results:
A. nummularia ssp nummularia was grazed in preference
to A. nummularia ssp spathulata at all sites.
Heritability for grazing preference: 0.26 to 0.62

17. Results:
Breeding values were calculated for each individual
shrub (20,000 plants at each site) for both
edible biomass and grazing preference for use in index
selection.
Based on a selection index for edible biomass and
grazing preference by sheep, 1000 plants were short-
short
listed at each site.

18. Selections within A. nummularia
selection index
1 Edible biomass + 1.5 Grazing preference
50
45
40
% Predicte gain
35
ed
30
Edible biomass
25
20 Grazing preference
15
10
5
0
Monarto Condobolin Tammin

19. Saltbush evaluation site at Tammin, NSW –
regrowth after grazing

20. Results:
Based on re-growth after grazing 100 plants were
selected at each site for nutritive value analysis
- (April 2009).

21. Nutritive value is the key selection factor
(Marta Monjardino, 2008)

22. Predicting organic matter digestibility of shrubs
(NIR method)

23. Predicted Organic Matter Digestibility
55.0
54.0
53.0
Predicted OMD (%)
52.0
O
51.0
50.0
P
49.0
48.0
47.0
47 0
Tammin across all Tammin EGG Tammin top 10
lines

24. Predicted Organic Matter Digestibility
56.0
54.0
52.0
Predicted OMD (%)
50.0
O
48.0
46.0
P
44.0
42.0
40.0
Condo across all Condo EGG Condo top 10
lines

25. Predicted Organic Matter Digestibility
58.0
57.0
%)
56.0
56 0
Predicte OMD (%
55.0
ed
54.0
53.0
52.0
51.0
Monarto across all Monarto EGG Monarto top 10
lines

26. Soluble Ash (% of DM)
Tammin EGG
Tammin top 10
Monarto EGG
Monarto top 10
Condo EGG
Condo top 10
0.0 5.0 10.0 15.0 20.0 25.0 30.0

27. 89 elite plants were selected for clonal propagation -
(May June 2009).
(May-June 2009)

28. Clonal propagation
%
striking
rate of
cuttings
Range Mean
Monarto 8.93 70.34
8 93 – 70 34 31.28
31 28
Condobolin 7.69 – 82.41 34.17
Tammin 9.59 – 85.80 46.91
EGG control 69.80
A. spathulatha 8.02
control

29. Clonal evaluation trial
Replicated trials of the 89 selected clones and the two
controls (EGG + spath) were planted at Monarto
(SA), Dareton (NSW) and Tammin (WA) in spring 2009.
Design
D i – row column – At each site 2184 plants (91 8 x 3)
l h it l t (91x
Data on dry matter production, animal preference and
nutritive value will be collected. These trials will help to
identify the best clone(s) for potential commercial release as
cultivar(s) by 2011.
( ) y

30. Clonal trial at Monarto, SA

31. Clonal trial at Dareton, NSW

32. Seed Cultivar development
Old man saltbush plant is dioecious (female and male plants).
Hybridisation nurseries are being established in SA.
SA
Hybrid lines will be developed for testing with the direct-
seeding method (by 2012).

33. Industry use Plan - Market Potential
y
The market potential for Old man saltbush in Australia and overseas is
extensive.
However, two major impediments to the uptake of new saltbush plantings
in Australia are: 1) cost of seedlings and
2) the risk of unsuccessful establishment.
establishment
Reduced planting incentives from the government may also limit uptake.
(Su ey
(Survey by Dr Anna Dutkiewicz, Adoption Manager FFI C C)
a ut e c , dopt o a age CRC)
Currently the major plantings of saltbush is by seedlings.
Cost of planting saltbush seedlings can vary between $650 to 850 per ha,
in contrast direct seeding can cost between $150 to 185 per ha
ha.

34. Acknowledgements:
Hayley Norman, CSIRO
Allan Rintoul, CSIRO
Peter Jessop, NSW DPI
p,
Eric Bailey, NSW DPI
Merv Tucker, DWLBC
Glenn Gale, DWLBC
Richard Mazanec, DEC; WA
Ed Barrett-Lennard, DAFWA Mike Bennell, formerly DWLBC
Joe Jacobs, DPI Vic
Jacobs David McKenna, formerly DWLBC
McKenna