Basics of Pesticide Resistance. Sam Markell, Ph.D. Extension Plant Pathologist

Transcription

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2 Basics of Pesticide Resistance Sam Markell, Ph.D. Extension Plant Pathologist

3 Outline Use of pesticides in North Dakota How does resistance occur? Risk factors

4 Million acres Pesticide Use in North Dakota Herbicides Insecticides Fungicides Pesticide Use Surveys Zollinger et al.

5 Percent of acres Pesticide Use on Wheat in North Dakota Herbicides Insecticides Fungicides Pesticide Use Surveys Zollinger et al.

6 Percent of acres Pesticide Use on Soybean in North Dakota Herbicides Insecticides Fungicides Pesticide Use Surveys Zollinger et al.

7 Reasons for increasing use

8 01/02/03 05/08/03 09/11/03 01/15/04 05/20/04 09/23/04 01/27/05 06/02/05 10/06/05 02/09/06 06/15/06 10/19/06 02/22/07 06/28/07 11/01/07 03/06/08 07/10/08 11/13/08 03/19/09 07/23/09 11/26/09 04/01/10 08/05/10 12/09/10 04/14/11 08/18/11 12/22/11 04/26/12 08/30/12 01/03/13 Cents/Bushel 2000 Cash Price for Spring Wheat - Minot, ND Jan. 2, Jan. 24, Spring Wheat Frayne Olson

9 01/02/03 05/22/03 10/09/03 02/26/04 07/15/04 12/02/04 04/21/05 09/08/05 01/26/06 06/15/06 11/02/06 03/22/07 08/09/07 12/27/07 05/15/08 10/02/08 02/19/09 07/09/09 11/26/09 04/15/10 09/02/10 01/20/11 06/09/11 10/27/11 03/15/12 08/02/12 12/20/12 Cents/Bushel Cash Price for Soybean - Hunter, ND Jan. 2, Jan. 24, 2013 Soybeans Frayne Olson

10 Reasons for increasing use Money Wet cycle Diseases like water Plant Health Concept of yield increase in absence of New/novel pests threats Resistant weeds, invasive species, outbreaks Insurance Application vs IPM Increased rates (glyphosate)

11 Our current situation High crop prices High usage of pesticides Applications when they may not be needed? Limited modes of action Shift in usage heavy dependence on single mode of action

12 How do pathogens become resistant to fungicides? Random mutation Selection pressure Survival of the fittest

13 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

14 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

15 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

16 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

17 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

18 Pesticide Resistance Sensitive to fungicide Resistant to fungicide

19 Resistance Risk Factors - Mode of Action Pesticide Multi-site: Pesticide is active against multiple/many Pesticide in metabolic pathway. Single-site: Pesticide is active against one specific point in metabolic pathway.

20 Not all FRAC etc. are equal risk! QoI (strobilurins): Headline, Quadris, etc Phenylamides: Ridomil Methyl benzimidazole carbamates (MBC) Thiophanate Methyl, Topsin Dicarboximides: Rovral, Iprodione FRAC 11 FRAC 4 FRAC 1 FRAC 2 High Risk High Risk High Risk Medium-High Risk SBI (Triazoles): FRAC 3, Low-Medium

21 Resistance Risk Factors - Pest Fecundity Waterhemp (in excess of 100,000 seeds/plant) Dry bean (not very many) Longevity Dormancy of seeds, overwintering, extended diapause, survival of cysts Variability Pathogens with sexual and asexual reproduction Outcrossing of plants (waterhemp)

22 Resistance Risk Factors - Human Multiple application of the same FRAC, IRAC, HRAC Cut and/or sub-lethal rates Fluroxypyr mixes - Kochia Bad timing of application Big weeds, epidemic in progress, not at thresholds Bad technique Nozzles, etc.

23 FRAC, IRAC, HRAC codes Fungicide (or other) Resistance Action Committee (FRAC) Based on Mode of Action (MOA) Labels will have codes on first page

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26 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

27 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

28 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

29 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

30 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

31 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

32 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

33 Pesticide Resistance Sensitive to fungicides Resistant to fungicide 1 Resistant to fungicide 2

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35 Resistance Summary Many factors point to pesticide increase Random pest variability, selection pressure, survival of the fittest Risk factors in pest, host, and usage

36 Thank You - Questions