Crop Biotechnology: a Weed Science Perspective

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Crop Biotechnologya Weed Science Perspective

• Harold D. Coble
• IPM Coordinator, USDA/OPMP
• hcoble_at_ars.usda.gov

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My Perspective

• Reared on small diversified farm in 1940s-50s
• Very familiar with the drudgery of hand hoeing
• College degrees in agronomy weed science
• Weed science extension research for 30 yrs
• Always been a farmer at heart
• A proponent of IPM USDA IPM Coordinator

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And, for many reasons, I believe in
conserving our natural resources
Photo credit USDA/NRCS
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Pest management is all about crop yield and
quality preservation and ease of harvest.
Photo credit USDA/NRCS
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Pest Management StrategiesThe PAMS Approach

• Prevention
• Cultural practices to keep pests out
• Avoidance
• Cultural practices to avoid or resist pest impact
• Monitoring
• What is present and how many
• Suppression
• Kill em if you need to

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Pest Suppression Options

• Physical
• Hand Weeding
• Mechanical Cultivation
• Other (mulches, , traps, etc.)
• Biological
• Insects, Bacteria, Fungi, Biochemicals
• Chemical
• Chemical Pesticides
• Pheromones

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Chemical Weed Control

• Historical non-selective chemicals (NaCl)
• Key to chemical use is selectivity
• Development of 2,4-D in 1940s
• Research programs for selective herbicides
• Rapid expansion of chemical use in 1960s 70s
• 100 major crop acreage treated today

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Attaining Selectivity

• Massive chemical screening programs
• Selection in crop breeding programs
• Tracy soybean
• Non-transgenic methods
• Sethoxydim-tolerant corn (tissue culture)
• STS soybean
• Transgenic technologies (Biotech)

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Growth of Biotech Acres of Total U.S. Acres
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Biotech Crop Uses
of Acres
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Western Corn Rootworm Adult
Photo credit USDA/ARS
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Why the Rapid Adoption?Herbicide Tolerant Crops

• Lower cost of weed control, even with technology
  fees
• Greatly simplified control procedures
• Higher degree of weed control
• Fewer chemical applications less trips
• Promotes more sustainable cultural practices
• Less tillage, less compaction, narrower rows
• Societal aspects (pride, landowner acceptance)

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Higher degree of control at lower cost
Photo credit USDA/NRCS
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And prevent disasters such as this
Photo credit USDA/NRCS
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Why the Rapid Expansion?Insect Protection (PIPs)

• High degree of control of target species
• Safety to beneficial species
• Human and environmental safety
• Food/Feed safety
• Applicator safety
• Wildlife safety
• Simplicity of control measures

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PIPs aimed at the major insect pest complexes
Photo credit USDA/ARS
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Plant-incorporated protectants designed to
avoid harm to beneficials
Photo credit USDA/ARS
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Whats the Downside?Herbicide Tolerant Crops

• Weed species shifts if integrated approach not
  used
• Prevention and avoidance strategies
• Continued field monitoring
• Alternative chemical mode of action
• Reduced availability of alternative MOAs
• Temptation to just plant and spray

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Weed resistance is a fact of life
Photo Craig Chism, Univ. of TN
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Whats the Downside?PIPs

• Risk of resistance development/selection
• Major concern of organic community
• Increased cost if populations below EIL
• Protection present whether needed or not
• Have led to secondary pest resurgence
• Stinkbugs in cotton

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Tarnished Plant Bug
Photo credit USDA/ARS
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Where do we go from here?
Tacos, Chicken feed, or Plastic??
Photo credit USDA/NRCS
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Meat, Milk, or Pharmaceuticals???
Photo credit USDA/NRCS
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Weve only just begun
Photo credit USDA/NRCS