Fungicide performance
The risk of yield loss has to be balanced against cost savings when selecting the appropriate dose.
Most fungicides are applied at doses well below those recommended by manufacturers. An important consequence is that liability for poor control no longer rests with the manufacturer. The risk of yield loss must be balanced against the potential financial benefits of using reduced doses, by selecting a fungicide dose that is 'appropriate' to a particular crop's needs.
Untreated crops suffer an amount of disease determined by local disease pressure and the disease resistance of the variety. Disease severity in fungicide-treated crops is related to the dose applied.
For any single spray in the programme, fungicide cost increases with dose applied. In each crop, yield loss is proportional to the amount of disease present, so a point on the dose-response curve is reached when the cost of any additional dose would not be paid for by the resulting yield increase. At this point, profit is maximised and the dose of fungicide applied is just the amount that is needed - by definition, the appropriate dose to apply.
Interactive fungicide performance curves for wheat diseases - 2007
Interactive fungicide performance curves for wheat diseases - 2006
Interactive fungicide performance curves for wheat diseases - cross years
Interactive fungicide performance curves for barley diseases
This is a link to the SAC website, where you should click on the button on the right hand side called "fungicide dose curves".
Barley disease control 2008 - SAC technical note
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Many factors influence the types and severity of diseases which affect crops, including variety, cultivation, weather conditions, sowing date, crop rotation and fungicides. This technical note describes how these factors can influence the severity of foliar, stem base and root dieases in barley and how you can use them to manage disease in an integrated disease programme.
To see the Annual Project Reports (2007), for HGCA current projects on this subject click on the titles below:
Up to date information on fungicide performance for wheat growers (Project Number 3025)
Sequences and mixtures in winter wheat according to disease risk(Project Number 3026)
Fungicide performance on barley - production of dose response curves to advise growers on fungicide efficacy and potential resistance (Project Number 3027)
Understanding fungicide mixtures to control Rhynchosporium in barley and minimise resistance shifts (Project Number 3028)
New fungicides for oilseed rape: defining dose response activity (Project Number 3200)
Since 2005 HGCA has funded dose-response activity work for new fungicides controlling phoma and light leaf spot in oilseed rape. Details are in the two documents below
New fungicides for oilseed rape: Phoma and light leaf spot in 2007 (Project Number 3200)
New fungicides for oilseed rape: Sclerotinia control in 2007 (Project Number 3200A)
New fungicides for oilseed rape: Sclerotinia control in 2006 (Project Number 3200A)
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