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Catalogue: GRDC Updates
The 2013 season demonstrated that the presence of armyworm in above threshold densities did not necessarily result in head lopping and associated crop losses... The season we set out to test the damage potential of armyworm in barley... Early work showed very high levels of infestation (up to 100% of racemes) resulted in no yield or oil content loss if the crop had adequate moisture...
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Catalogue: GRDC Publications
" Goondiwindi GRDC Grains Research Update Day 1 - Tuesday 4 th March Time Topic Speaker (s) 10:00 AM James Clark (Chair Northern Welcome Panel GRDC) 10:10 AM General plenary (Supported by North West Local Land Services) 10:10 AM 10:40 AM.. Overall, both models are acceptable for modelling soil evaporation over a range of soils and seasons provided accurate soil physical properties and starting water states are known... Overall, populations increased five times compared to before planting the summer crops, but remained below 250/kg soil (Figure 4)...
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Catalogue: GRDC Publications
GRDC Grains Research Update Goondiwindi, March 2014 as yields increase, i.e. the bug threshold for a 4t/ha soybean crop is twice that for a 2t/ha crop (Fig. 2), and similarly for mungbeans - see comparison between 1t/ha and 2t/ha crops (Fig. 3)... In summary, action thresholds for edible soybeans and mungbeans are set for bug populations predicted to damage 2% and 1.4% of seeds respectively... GRDC Grains Research Update Goondiwindi, March 2014 rule of thumb, aim to sample 5 widely-separated sites throughout a crop, with at least 4 x 1 m samples per site...
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Catalogue: GRDC Updates
Taking the angst out of thresholds in the computer age.. Podsucking bug thresholds are based on seed quality, and are influenced by a multitude of factors, including bug species, bug stage, yield, mean seed weight, time to harvest, and for crushing soybeans; crop value and cost of control... Given the 4-way interaction of cost of control, crop value, yield and mean seed weight in crushing soybean thresholds, the only way to determine bug thresholds is with the new downloadable threshold calculator...
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Catalogue: Ground Cover
Beat sheet and sweep net sampling of faba beans both severely underestimate the density of helicoverpa larvae, particularly smaller ones; a visual inspection is critical to improving pest number estimates.. Populations may be exceeding threshold before this is detected," Dr Miles says... Insect damage is not responsible for the majority of defective grain but further analysis is warranted to consider how the pod damage caused by helicoverpa may be contributing to weathering and poor colour in faba beans by allowing entry of fungi and bacteria...
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Catalogue: Ground Cover
Beat sheet and sweep net sampling of faba beans both severely underestimate the density of helicoverpa larvae, particularly smaller ones; a visual inspection is critical to improving pest number estimates.. Populations may be exceeding threshold before this is detected," Dr Miles says... Insect damage is not responsible for the majority of defective grain but further analysis is warranted to consider how the pod damage caused by helicoverpa may be contributing to weathering and poor colour in faba beans by allowing entry of fungi and bacteria...
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Catalogue: Ground Cover
Canada puts its faith in canola.. Canada's domestic canola-crushing capacity is increasing and will expand by 2.5 million tonnes this year alone, Canada Grains Council secretary Dennis Stephens told delegates at this year's Australian Grains Industry Conference... The distance to port from its arable prairies, which produce 80 per cent of the country's grain, is 1700 kilometres to the west and 3500km to the east, while its climate also gave growers just 100 frost-free days a year. "..
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Catalogue: GRDC Updates
A new helicoverpa threshold model replaces the old nominal (fixed) threshold of 1 larvae/m2 for flowering/podding mungbeans ... Until further data is available, the new threshold model applies to all crop stages from budding to late podfill... Helicoverpa damage was assessed at the end of each infestation and also at harvest...
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Catalogue: Ground Cover
" Date: 24.01.2008 New flexible thresholds for helicoverpa in mungbeans p24_helicoverpaa By Emma Leonard Summer pulses such as mungbeans and culinary soybeans target the higher-value, culinary markets and have a low tolerance of bug damage... [Photo (left) by Hugh Brier: The helicoverpa threshold trial at Kingaroy used caged mungbeans artificially infested with helicoverpa at five densities at flowering and late podfill in the development of flexible agro-economic control thresholds... Replacing the previous fixed (nominal) threshold of one larva per square metre, this model allows thresholds to be tailored for specific crop value and cost-of-control scenarios...
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Catalogue: GRDC Updates
Less common is are the thresholds designed to minimise population build up to damaging levels, because of subsequent difficulties in controlling populations once they start causing damage... The thresholds calculated by these models represent the 'break even' point where the cost of control equals the value of likely yield loss... Mirid activity measured in cumulative mirid days from budding to early podfill...
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