GRDC Research Updates
This page contains papers from the GRDC Update series for both growers and advisers.
For further information Updates and, please visit the following sites:
- GRDC Research Update Dates - upcoming Updates, agendas and subscriptions
- GRDC Update Newsletters
- ICN00011 - GRDC Research Updates - Northern Region
- ORM00001 - Research GRDC Research Updates - Southern Region
- GIA00001 - GRDC DAFWA Grains Research Updates - Western Region
To view any paper in full, click on the title below:
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Diseases shared by different crops and issues for crop sequencing
13.09.2011
• Appropriate crop sequences can make significant contributions to the management of important diseases of the major summer crops in the northern region
• A thorough knowledge of the host range and the biology the major pathogens of summer crops is vital when planning crop sequences
• Crop sequencing is only one component of an integrated disease management plan
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Fusarium stalk rot in sorghum - types, damage and management
13.09.2011
• Fusarium species are sometimes, but not always, associated with sorghum lodging
• Two species, Fusarium thapsinum and Fusarium andiyazi, are the major species causing fusarium stalk rot in the grain sorghum crops
• Sorghum species are the only known hosts of F. thapsinum and F. andiyazi in Australia
• Pre-harvest desiccation using a herbicide can predispose sorghum stalks to invasion by these Fusarium species
• Rotations, good agronomic practices, timely application of desiccant herbicides and prompt harvesting after desiccation can minimise losses from Fusarium-associated lodging
• There is evidence that hybrids differ in their tolerance to stalk invasion by Fusarium species after desiccation
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Targeting high yields in dryland grain sorghum in northern NSW: row direction, row spacing and plant population
13.09.2011
• In exceptional growing seasons such as those of the 2007/8 season, grain yields of sorghum will be largely not influenced by variations in row direction, population or row spacing.
• There was no effect on yield of sowing in a north/south versus east/west direction on sorghum grain yield in this season.
• There was no effect of narrow (37.5 cm) compared to 75cm wide row spacing at either of the two sites, Premer and Somerton on yields of 8.8 and 6.0 t/ha respectively. However effects on plant structures were noted.
• There was no effect on yield of plant populations from 29 – 67,000 plants/ha at Premer or 48 – 72,000 plants/ha at Somerton, however the population of 37,000 plants/ha yielded 2 t/ha less than the other populations at Somerton.
• Further research into the impact of row direction on sorghum production is needed under less favourable seasonal conditions to determine if increased light interception from a north/ south orientation increases yields in sorghum, as it has been demonstrated to in wheat. Other factors such as weed burdens would also need to be investigated.
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What the world wants from Australian wheat
13.09.2011
The focus of this paper is on the wheat industry.
• Traditional exporters, the United States, Canada, Australia and Argentina, export about 65 million metric tonnes (MMT) per year.
• Of this, Australia exports about 12 MMT/yr.
• Black Sea port countries export about 34 MMT/ year.
• Population is a long-term driver for wheat demand.
• World area planted is about 200 million hectares and yield growth is the key to meeting demand.
• The risky world market is driven by inelastic (near vertical) demand and supply relationships.
• Shares of total world exports and shares of total world wheat production over the period 1960/61 to 2009/10 have declined for both Canada and the United States while Australia’s shares have remained steady. Can this be continued into the future? The Black Sea port countries have dramatically increased their shares.
• There are many importing countries with most importing less than 5 per cent of total exports.
• Australian wheat is valued by importers but has some challenges in relation to consistency, quality management and information provision.
• Different end-products require different wheat qualities and different qualities provide the foundation for price discrimination.
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Insects in stored grain - resistance update, measuring aeration flow rates in silos
13.09.2011
While strong resistant pests in farm storages maintains a 2 – 4 % detection level over recent years, wide spread detection of strong phosphine resistant strains of Flat grain beetle ( Cryptolestes spp. ) in the central handling system is of serious industry concern.
Correct use of phosphine is essential to ensure future use of this fumigant is not made redundant.
Using the other valuable tools for pest management - regular monitoring, good hygiene and aeration, can go a long way to reducing our current over-reliance on phosphine.
Checking airflow performance of aeration systems used on grain storages is just one step towards extracting the maximum benefits from this valuable grain quality and pest management tool.
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The coming famine - risks and solutions for the food challenge of the 21st century
13.09.2011
Feeding 10 billion people sustainably in the late 21st century will be the greatest challenge humanity and science have ever faced. While food demand will double by 2060 there are emerging scarcities of all the main resources required to produce it – water, land, energy, nutrients, science, fish, finance and stable climates. These challenge us to rethink food itself, to develop new farming systems, diets and food products for the future that are healthy, creative, delicious and tread less heavily on the planet.
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Improving the efficiency of nutrient responses - testing and applying P and K (and S?)
13.09.2011
Soil P and K reserves have declined, and in some situations reached levels limiting crop growth – especially in the 10-30cm layer where most uptake of these nutrients occurs in drier conditions. Soil test after looking at yield maps or soil type areas to identify potential fertility constraints, and make sure you test both the topsoil (0-10cm) and subsoil (10-30cm).
Research on placement and depth of P and K fertilisers is currently underway for grains and cotton, with indications of stronger responses as the volume of fertilized soil is increases (ie. more frequent bands). Initial attempts to examine single nutrient responses can be complicated by the fact that a number of sites appear to have multiple nutrient limits on crop growth. Fixing a low P condition may have little impact unless other limiting nutrients are also addressed (ie. K or S).
Combinations of P, K and/or S in field experiments are producing some strong crop responses. However, if yield potential is increased significantly it is important to remember that more available N (soil reserves and fertiliser) will be needed to meet the greater yield target.
Consider doing some on-farm test strips and/or plant tissue testing to monitor crop status, especially in poorer performing parts of the paddock.
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Efficacy, rates and timing of Tilt (propiconazole) for control of powdery mildew in sunflower
13.09.2011
TILT 250EC has excellent efficacy against sunflower powdery mildew.
Under conditions of moderate powdery mildew infection, one application of TILT 250EC at a rate of 500 mL product/ha applied when 5% of ray florets have emerged gives good control of powdery mildew throughout the canopy until harvest.
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Cotton fusarium wilt: impact of rotation crops on disease carryover
13.09.2011
• Adopt suitable stubble management strategies
o Pulling and mulching infected cotton stubble and retaining it on the soil surface for at least a month prior to incorporation is the best treatment to reduce in-field Fov spore levels.
• Adopt suitable rotation options
o Bare fallow rotation prior to cotton helps reduce disease severity in the subsequent crop.
o A summer sorghum/maize - fallow-cotton rotation can increase cotton plant survival, reduce disease incidence and increase yields in the 3rd year when compared to continuous cotton.
o Legumes such as soybean and mungbeans increase disease so potentially should be avoided in infected fields.
o When using cereal rotations, burn, bury or bale the cereal residues as soon as possible after harvest.
• Residue and organic matter levels influence field pathogen survival and disease incidence.
o Although there were no differences in latest trials between retaining and incorporating residues in either maize or sorghum, the current practice is to retain residues on the surface.
o Many alternate crops when grown in naturally infested soil are infected by the Fusarium wilt pathogen, with infection limited to lower stem and root tissue in some crops only.
o The use of green manuring crops can increase the Fusarium soil population.
• Grow only the most resistant cotton varieties available (varieties with high F-ranks) in fields known to be infested with Fusarium wilt.
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Sprayed vs unsprayed National Variety Trials in 2010 - what did we learn?
13.09.2011
It needs to be reemphasised that the 2010 season was a particularly high yielding year characterised by good rainfall with an extended, mild grain-fill period which was very conducive to both the development of and yield loss from stripe rust. It is reasonable to assume that yield responses to stripe rust in 2010 were higher than would be expected on average. Under these conditions clear economic benefits were obtained from managing stripe rust in varieties rated MR-MS or lower while it was not economical to manage stripe rust in varieties rated R-MR or better.
The economics of managing stripe rust in MR varieties was marginal and would not have been economical in one of the five varieties examined (EGA Bounty
,). Note: all fungicide applications in the nine NVT trials were applied by ground rig to small plots. If one or both of these fungicides were applied by air at a cost closer to $20/ha for each application (compared to $8/ha for ground rig), which was a fairly common commercial reality in 2010, this would have made fungicide management in the MR varieties not economical.Yield responses observed in these NVT trials were generally obtained using a relatively expensive two spray program. These responses may not occur with different fungicide programs (single sprays, lower application rates or different timings). Additionally, a 0.52 t/ha yield benefit (at $200/t grain price) needs to occur to return $2 for every $1 spent controlling stripe rust using this strategy. This provided a marginal economic return in MR varieties in 2010 which was an above average season that produced yields of around 5 t/ha. Achieving an additional 0.52 t/ha of grain from fungicide application would be expected to be even more difficult in an average season with yields closer to 3 t/ha or in historically lower yielding environments.
