IPM in wheat

The EU requires IPM by what does this mean??? 1.Blind Chemical control –Schematic and routine treatments 2.Chemical control based on advice –Recommendation given by region often using broad spectrum pesticides 3.Specific control –Use economic threshold levels. differentiate between pesticides (including impact on beneficials) 4.Integrated plant protection –Use mainly cultural methods and only limited input of pesticides 5.Integrated agricultural production –Use and exploit all positive factors in the agro-ecosystem Definition given by IOBC

Two case studies: –fungicides in cereals –herbicides in cereals

National monitoring of diseases Data on variety susceptibility Data on fungicide efficacy. Need for lots of field trials which support the use of reduced rates Implematation of threshold models Elements in wheat IPM

Need for treatment No need (45 loc.) Monitoring network

Susceptible variety Resistant variety

Major thresholds in wheat DiseaseExamples of threshold in CPO Eyespot >35% plants attacked at GS Mildew >10% plants attacked from GS 29 (S) >25% plants attacked from GS 29 (R) No treatments after GS 40 Septoria 4 days with precipitation from GS 32 (S) 5 days with precipitation from GS 37 (R) Or attack on third leaf from GS Brown rust >25% plants attacked (S) Yellow rust GS > 1% plants attacked (S)

TFI –dose /ha Dt/ha grain per ha Gross yield Net yield Control of Septoria in wheat -different input 6 trials from DK Appropriate and reduced dosages of fungicides

Resistant cultivar Susceptible cultivar A: GS B: GS C: GS D: GS Optimal dose depends on cultivar and grain price

TFI/Relative dose Source: Farmstat/Kleffmann/Pesticide statistics Development of fungicide use in winter wheat

Dose. l/ha Net loss compared with optimum. dt/ha Source: Danish Agricultural Advisory Service Summary of 73 Danish field trials on ear treatment in winter wheat

TFI Fungicides Winter wheat Spring barley Official statistics ( ) Target CPO (trial results) Fungicide use stays close to the optimum

Herbicide performance is affected by many biotic and physicochemical factors such as: –weed flora –growth stage of weeds –crop competitiveness –climatic conditions –application technique –adjuvants –the presence of other pesticides in the spray solution Herbicides in cereals

Efficacy profile for 60 weed species

DSS for weed control

Treatment Frequency Index Net yield loss compared with optimum dose. dt/ha Source: Danish Agricultural Advisory Service Summary of 130 Danish field trials on weed control in spring barley

TFI FungicidesTFI Herbicides Winter wheat Spring barley Winter wheat Spring barley Official statistics ( ) Target CPO potential

Why is the current herbicide use in cereals onsiderably higher than the targets? –Because an integrated approach was not adopted

Decision-making for weed control is a three step procedure –Consider preventive measures such as crop rotation or cultivation techniques to reduce the potential losses due to weeds –Assess the need to apply herbicides (threshold) –Herbicide choice and dose rate

Monitoring for weeds is difficult and time consuming

Autonomous sprayer with weed sensor. The future?

Conclusions: –Only integrated pest control approaches will be sustainable –Integrated disease and insect control can often be practised without major changes in the cropping practice (1-year perspective). –Integrated weed management often requires major changes in cropping practices (multi-year perspective)

Barriers for using thresholds and DSS As little as possible. as much as neccessary

Factors influencing the optimal theoretical pestice need Spray capacity. No. of hours to spray. timing Family. spare time. holidays. Risk of crop failure Scaling up trials to fields Problematic areas. limited harvest capacity. Employees. education. working hours Climate changes. unknown factors. Poor control experiences Other activities on the farm. animal. job? Management and available information Optimal pesticide use in DK TFI Price relations

What do growers want? Reliable and robust solutions Economically sound solutions Simple and easy messages A dialogue with advisors If they should do something else; they need incentives!

Jokers! Increasing problems with fungicide resistance Limitations in available fungicides (DK has no chlorothalonil, prochloraz) Registration of heavy-loaded fungicides triazole mixtures! Climate changes have been estimated to increase disease risk and TFI