THE RELATIVE PERFORMANCE AND TARGETING RELIABILITY OF SUMMER CROPS (MAIZE & SUNFLOWERS) COMPARED TO GRAIN SORGHUM

| Date: 03 Sep 2008

 Take home message

Sorghum
·         The highest yields were obtained at both sites from sowing time 3 (November).
·         Over both sites, comparisons of the effect of maturity on sorghum yields showed there was no significant difference between maturity groupings.
Maize
·         Across all maturity groupings the highest yields were obtained from maize when sown on the 3rd planting time at Tamworth and Moree.
·         Sowing time 4 had a significantly lower yield across all maturity groupings for maize.
Sunflower
·         The long season hybrids yielded better at both Moree and Tamworth.
·         There was no significant difference between sowing time 1 and 3 at Tamworth.
Sunflower and Maize compared to Sorghum
·         Maize performance was better than sorghum or equal to in most sowings in the past summer. This is not expected to be a usual trend.
·         Sunflower yields are likely to remain around the ½ to 1/3 the yield of sorghum.

 

Background

Sorghum is the major summer crop in northern NSW, occupying on average 69% (160,000ha) of the total summer crop area (230,000ha), with sunflowers second at 13% of average area (16,000ha). Maize is a relatively minor summer crop accounting for 5% of the mean total area sown. The objective of these experiments was to:
·         determine the relative performance of maize and sunflower compared to sorghum
·         evaluate if the performance could be made more reliable by using different hybrid maturities or by varying sowing time
·         evaluate if there are alternative opportunities to include sunflower, sorghum and maize in the summer cropping window.
 
Apart from using tactical sowing opportunities to take advantage of good soil moisture conditions, summer crops may be sown early or late to avoid the stress of flowering and grain fill during peak summer temperatures.
 
Current maize, sorghum and sunflower hybrids offer a range of maturities which should be considered when assessing their suitability to early or late sowing opportunities under dryland conditions. 
 
As an example, quicker maturing maize varieties could have an advantage under dryland conditions by:
·         Taking advantage of a full profile of soil water and minimising the risk of running out of water before the crop matures;
·         Avoiding the peak summer heat at tasselling when planted in early spring;
·         Avoiding frost damage if planted late.

 Methods

Maize, sorghum and sunflower
Two trials were conducted in the 2007/08 season, Biniguy, east of Moree and Bithramere, west of Tamworth. Each site included four potential sowing times and three crops; sorghum, maize and sunflower; with 12 hybrids for each crop. The 12 hybrids were selected based on their relative maturity and classed as quick, medium or long season. The sowing times were:
 
Sowing Time
Moree Site
Tamworth Site
1
6th & 7th September, 07
10th & 11th September, 07
2
Not sown due to a lack of rain*
Not sown due to a lack of rain*
3
21st & 22nd November,07
14th, 15th & 16th November, 07
4
15th & 16th January,08
11th & 12th January, 08
* intended to have been planted early Oct at Moree and mid Oct at Tamworth.
 
The hybrids included in the trial were:
Crop
Maturity
 
Quick
Medium
Long
Sorghum
MR Striker
85G08
Exp 4666.1101
Venture
MR Buster
86G86
Banjo
Dominator
Pac2423
Bonus.MR
Overflow
Enforcer
Maize
quick 90-100 CRM
med 101-110 CRM
long 111-120 CRM
36H36
PACM592
Emperor TL MYF140SM
Hycorn 533
34N43
Cobber Flint
Maximus
Hycorn 424
32P55
Exp. 8821.8501
Hannibal
Sunflower
T40318
Ausigold 52
Sunoleic 06
Ausigold 7
Hysun 38
Ausigold 62
Advantage
HP002GN
Hyoleic 41
Ausigold 4
HP004GN
Hysun 39

 

Results & Discussion

Individually, each of the crops showed differences in their yield ability over the 3 sowing times. Maturity group differences were also noted in most crops.
 
Sunflower
At Tamworth there was no significant difference in yield, between sowing at time 1 or 3. However, sowing time 4 yielded significantly less, primarily due to bird damage, which did not occur on either of the earlier sowings. At Moree, whilst all time of sowings were sown, only the first time of sowing was harvested due to extensive bird damage when no crop was surrounding the trial.
 
Table 1: Effect of sowing time on sunflower yield
 
Moree Site
Tamworth Site
Sowing Time
Yield (t/ha)
Yield (t/ha)
1
1.311
2.5437a
3
n/a
2.2316a
4
n/a
0.3583b *
Lsd (5%):
n/a
0.34t/ha
* bird damage
 
However, when including maturity into the analysis, the long season hybrids yielded better at both Moree and Tamworth.


Table 2: Effect of hybrid maturity and sowing time on sunflower yield
Moree Site
Tamworth Site
 
Sowing
Time
Maturity
Yield (t/ha)
Sowing Time
Maturity
Yield (t/ha)
1
Long
1.51a
1
Long
2.82a
-
3
Long
2.66ab
 
1
Quick
1.08b
1
Quick
2.51abc
 
1
Med
1.34ab
1
Med
2.29bcd
 
-
3
Quick
2.14cd
 
-
3
Med
1.89d
 
-
4
Long
0.44e
 
-
4
Quick
0.37e
 
-
4
Med
0.26e
 
 
 
 
 
 
 
 
Lsd (5%):
 
0.27t/ha
 
 
0.44t/ha
 
 
* only one time of sowing for sunflower at Moree due to bird damage
 
Sorghum

The highest yields for sorghum were obtained at the Tamworth site at sowing time 3. In addition, sowing time 1 was significantly better than sowing time 4. To compare the sowing times, sowing time 1 and sowing time 4, yielded 77% and 40% of sowing time 3 respectively. At Moree, the highest yields were also obtained for sowing time 3. Sowing time 1 also yielded significantly better than sowing time 4.

Table 3: Effect of sowing time on sorghum yield
 
Moree Site
Tamworth Site
Sowing Time
Yield (t/ha)
Yield (t/ha)
1 - Sept
3.36b
5.42b
3 – Nov
4.47a
6.98a
4 – Jan
2.68c
2.79c
Lsd (5%):
0.586t/ha
0.64t/ha
 
Over both sites, comparisons of the effect of maturity on sorghum yields showed there was no significant difference between maturity groupings.
 
Table 4: Effect of hybrid maturity and sowing time on sorghum yield
Moree Site
Tamworth Site
Sowing Time
Maturity
Yield (t/ha)
Sowing Time
Maturity
Yield (t/ha)
3
Quick
4.56a
3
Long
7.22a
3
Long
4.55a
3
Med
6.93a
3
Medium
4.30ab
3
Quick
6.81a
1
Medium
3.62bc
1
Med
5.65b
1
Quick
3.30cd
1
Long
5.34b
1
Long
3.17cd
1
Quick
5.25b
4
Long
2.78d
4
Quick
2.97c
4
Quick
2.73d
4
Med
2.92c
4
Med
2.52d
4
Long
2.48c
Lsd (5%):
 
0.786t/ha
 
 
1.12t/ha
 
Maize

At the Tamworth site, the highest yields were obtained from maize when sown on the 1st or 3rd planting time. The latest planting time (4th sowing) in January had a significantly lower yield, in fact only 53% of the yield of the first two sowing times.

 
At the Moree site, across all maturity groupings, the highest yields were obtained from maize when sown on the 3rd planting time. The 1st sowing time also yielded significantly better than sowing time 4. Interestingly, the highest yields were obtained from a medium maturity group on sowing time 3 at both sites. Sowing time 4 had a significantly lower yield across all maturity groupings for maize. However, this was a particularly mild summer and recommendations should not be made on one year’s data. 
 
Table 5: Effect of sowing time on maize yield
 
Moree Site
Tamworth Site
Sowing Time
Yield (t/ha)
Yield (t/ha)
1 – Sept
4.01b
7.22a
3 – Nov
7.05a
7.27a
4 – Jan
2.45c
3.89b
Lsd (5%): 
0.38t/ha
0.65
 
Table 6: Effect of hybrid CRM and sowing time on maize yield
Moree Site
Tamworth Site
Sowing Time
Maturity
Yield (t/ha)
Sowing Time
Maturity
Yield (t/ha)
3
Medium
7.34a
3
Medium
8.49a
3
Long
7.12ab
1
Long
7.54ab
3
Quick
6.7b
1
Medium
7.09b
1
Medium
4.33c
1
Quick
7.04b
1
Long
4.27c
3
Quick
6.69b
1
Quick
3.43d
3
Long
6.65b
4
Medium
2.86de
4
Quick
4.53c
4
Long
2.28ef
4
Medium
4.06cd
4
Quick
2.22f
4
Long
3.103d
Lsd (5%):
 
0.60t/ha
 
 
1.13t/ha
 

 

Comparative crops performance with sorghum

The 2007/8 results were in contrast to trials conducted in 2005/06 and 2006/07 when as a rule of thumb, sunflower yields were approximately ½ and maize 2/3 that of sorghum. In the 2007/8 season, the comparative performance of maize was significantly better than expected with maize outperforming sorghum in all sowing times.
 
In 2007/8 at Tamworth, the comparative performance was in the order of:
·         September plant - sunflowers yielded ½ of sorghum; maize yielded better than sorghum (sorghum was ¾ of maize).
·         November plant - sunflowers yielded 1/3 of sorghum; maize yielded equal to sorghum.
·         January plant - sunflowers yielded 1/8 of sorghum; maize yielded better than sorghum.
 
At the Moree site a similar average pattern was measured with sunflower yielding 39% of the sorghum yield on a spring plant and maize out yielded sorghum with the exception of the late plant. In summary:
·         September plant - maize yielded 119% that of sorghum
·         November plant - maize produced 224% of the sorghum yield. However it should be noted that some of the sorghum hybrids suffered midge damage during this sowing time.
·         January plant - maize was 91% of the yield of sorghum and was actually harvested just prior to physiological maturity for some of the maize hybrids, which impacted on seed weight and consequently yield.

 Conclusion

In the 2007/8 season, the performance of maize was better than previously measured compared to sorghum across all three sowing times. Significantly higher yields were obtained for maize from sowing times 1 and 3, over sowing 4. The performance of sunflowers compared to sorghum was similar to that previously measured.
 
There are opportunities to move the sowing window for maize, sorghum and sunflower. Selecting hybrids based on maturity can also aid in improving the reliability and performance of some summer crops. Results are from a limited number of seasons, the trials should be repeated over a range of seasons. The next phase of the ACIAR project will model these results using APSIM over a range of conditions and seasons.
 
Finally, this was a particularly mild summer and recommendations should not be made on one year’s data.

 Acknowledgements

Funding from the NSW Department of Primary Industries and the Australian Centre for International Agricultural Research (ACIAR) is gratefully acknowledged (ACIAR Project ASEM/2000/109).
 
We would also like to thank the co-operating growers for their assistance throughout this project – Michael & Marianne Ledingham, “Merinda” Biniguy and Richard, Gai and Michael Bowler “Kemendine” Bithramere. 
 
Thanks also to Bruce McCorkell & Steve Harden, NSW DPI Tamworth for data analysis.

Contact details

Loretta Serafin
District Agronomist, Tamworth
NSW Department of Primary Industries
Ph: (02) 67 63 1100
Mb: 0427 311 819
Fx: (02) 67 63 1222
Email: loretta.serafin@dpi.nsw.gov.au
 
Stephanie Belfield
Consultant
HMAg Pty Ltd, Moree
Mbile 0458 311 412
Email: stephbelfield@bigpond.com