Contents - Greenmount Press
Contents - Greenmount Press
Contents - Greenmount Press
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Outside of the weather, which we know can be hard to<br />
control, the number one impact on plant establishment is the<br />
management that is applied at planting time.<br />
Some work that was carried out by Dr Steve Allan from CSD<br />
last season in southern NSW picked up a number of issues that<br />
were occurring when planting. In Figure 3, look at the sowing<br />
depths for Condobolin and Whitton.<br />
In this example, four by one metre soil transects were evaluated<br />
showing the depth of seed in a side profile. In these examples, we<br />
are seeing a range of depths from two to five cm at the same sites<br />
in the same transects, which can only be caused by one thing. The<br />
planter is travelling at speed, and ‘popping’ is occurring with the<br />
seed being bounced in the soil profile. This causes a number of<br />
issues such as seed not planted into moisture, late germination,<br />
and gappy stands due to seedling death.<br />
FIGURe 3: Emergence and establishment<br />
assessment southern NSW<br />
FIGURe 4: Soil temperatures at Hillston, Whitton<br />
and Jerilderie<br />
FIGURe 5: Population trials at Hillston,<br />
Darlington Point and Narrandera<br />
Planting dates and time of emergence<br />
Sites at Whitton, Dpt1, Jerilderie, Hilt1, HilH3 and HilM3 took<br />
from 18 to 24 days to emerge with the Jerilderie site being a<br />
replant and the others sites being late in maturity. In comparison<br />
Condobolin, Dpt2 and HilJ1 that are highlighted were planted<br />
into October only took seven days to emerge. This supports the<br />
theory of picking the best forecast for rising temperatures and<br />
planting on that. This is supported by the weather data for the<br />
region. Late September and early October temperatures were<br />
very cool as seen in Figure 4.<br />
Soil Temperatures at these sites were cool up until October<br />
11 when temperatures began to rise. The Jerilderie site that was<br />
replanted was estimated to cost the grower two bales per hectare<br />
in yield.<br />
Another way of ensuring that a good even plant stand is<br />
obtained is to plant slightly heavier than what would be normal<br />
on your farm. There is no significant yield loss by having extra<br />
plants in your plant stand up until a point (around 15–16 plants<br />
per metre), but as mentioned before, a skippy stand will cause a<br />
reduction in yield. This was supported by work that was carried<br />
out last season with three population trials conducted in southern<br />
NSW. Planting rates of 20, 16, 12 and eight kg per hectare were<br />
evaluated. In Figure 5 we see the results of these trials.<br />
There was no significant difference in yield between each of<br />
the populations at all three sites. A slight increase in yield was<br />
seen in the eight kg per hectare treatment at Darlington Point,<br />
but was not significant. In the trial planted at 20 kg per hectare,<br />
plant stands came out between 15–16 plants per metre and<br />
similarly the eight kg per hectare treatment had plants stands<br />
between five to seven plants per metre.<br />
The results suggest that if there are rough planting conditions,<br />
or for instance moisture is slightly variable, a heavier planting rate<br />
could be used with no yield reduction so that a consistent plant<br />
stand can be obtained.<br />
This work is supported by results from population trials<br />
conducted in the northern growing regions as seen in Figure 6.<br />
There is no significant yield difference between populations<br />
from six to 17 plants per metre.<br />
Other things to consider at planting time:<br />
■■<br />
Soil bed preparation;<br />
■■<br />
Irrigation scheduling – pre-water or watering up;<br />
■■<br />
Planter inspection and calibration;<br />
■■<br />
Temperature monitoring of the soil at 10 cm;<br />
■■<br />
Protecting the seed from insects using a suitable seed<br />
treatment; and,<br />
■■<br />
Making staff aware of planting issues through training.<br />
For further information in relation to any of the topics mentioned in this<br />
article, please contact your local CSD Extension and Development<br />
Agronomist or visit the web site www.csd.net.au<br />
FIGURe 6: CSD plant population trials<br />
October–November 2012 The Australian Cottongrower — 57