Agricultural Research Service Natural Products Utilization Research Unit
The General Need for Effective and Economical Bioherbicides
National Center for Natural Products Research Stephen O. Duke
United States Department of Agriculture – Agricultural Research Service Science, Aug 16, 2013
“Weeds remain the largest concern of farmers” - Science, Aug 16, 2013
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Köhler & Triebskorn – 2013 – Science 341: 759
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Data from: Timmons, 1970; Appleby, 2005, and HRAC
25
20
15
10
Modes Modes of Action
5
0 1920 1930 1940 1950 1960 1970 1980 1990 2000 2010 2020 Year
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 another fine mess you've gotten us into
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014
Solutions:
New herbicides with old MOAs?
Old herbicides/new resistant crops?
Bioherbicides?
New herbicides with new MOAs?
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Biopestides according to EPA
Microbial pesticides (biocontrol organisms, such as mycoherbicides)
Biochemical pesticides
Plant-incorporated protectants (e.g., Bt toxin produced by a transgene)
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Biochemical pesticide
Naturally occurring substance that controls pests by non-toxic mechanisms
Biochemical pesticides include substances, such as insect sex pheromones, that interfere with mating, as well as various scented plant extracts that attract insect pests to traps. Because it is sometimes difficult to determine whether a substance meets the criteria for classification as a biochemical pesticide, EPA has established a special committee to make such decisions.
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Fungicide 27%
Herbicide 7% Insecticide 66%
Biochemical Biopesticides Approved by EPA (1997-2010)
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Biological control organisms by pesticide taraget approved by EPA (1996-2010)
2
6 (13%) Fungi Insects 9 Weeds 29 Nematodes
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Biochemical bioherbicide options for green and organic production
Bioherbicides
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Approved bioherbicidal products for organic weed management
Essential oils
Crude botanical preparations
Vinegar
Natural lipids and soaps
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014
Example of essential oil
50% lemon grass oil (rich in d-limonene) Non-selective
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Organic acids
20% citric acid
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Horticultural vinegar
20% acetic acid from a natural source with yucca extract as a sticker
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Mixtures
12% clove oil, 8% sodium laural sulfate and also vinegar and citric acid
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014
Chelated iron products (FeHEDTA) – hazardous ingredients - NaNO3 and nitrilotriacetate
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Crude botanical preparation
Crab grass killer – 0.95% cinnamon bark Somewhat selective Effective at > 500 kg/ha formulated product
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Downside to these products
Poor efficacy
Very high use rates
High cost
Mostly non-selective
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Comparative Costs of organic weed management
Young, S.L. 2004. Natural product herbicides for control of annual vegetation along roadsides. Weed Technology 18: 580-587 United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Typical example of pest management costs in organic agriculture
Organic strawberries in California
Weed management - $2085/A Other pest management - $696/A
2006 Univ. Calif. Coop. Exten. Bull. St-CC-06-O
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Bialaphos – Only herbicide currently sold that is produced by fermentation
Tripeptide proherbicide converted to L-phosphinothricin in target plant
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 Better bioherbicides are badly needed to solve problems of both greener conventional and organic weed management
Economical and The holy grail of effective bioherbicides = biopesticides
United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014 United States Department of Agriculture – Agricultural Research Service IR-4 biopesticide workshop – Sept. 10, 2014