crop biotechnology: a weed science perspective harold d. coble ipm coordinator, usda/opmp...
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Crop Biotechnology:Crop Biotechnology:a Weed Science Perspectivea Weed Science Perspective
Harold D. Coble
IPM Coordinator, USDA/OPMP
My PerspectiveMy Perspective
Reared on small diversified farm in 1940s-50sVery familiar with the drudgery of hand hoeingCollege degrees in agronomy & weed scienceWeed science extension & research for 30 yrsAlways been a farmer at heartA proponent of IPM – USDA IPM Coordinator
Photo credit USDA/NRCS
And, for many reasons,I believe in conservingour natural resources
Pest management is all about crop yield and qualitypreservation andease of harvest.
Photo credit USDA/NRCS
Pest Management StrategiesPest Management StrategiesThe PAMS ApproachThe 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
Pest Suppression OptionsPest Suppression Options
Physical– Hand Weeding– Mechanical Cultivation– Other (mulches, , traps, etc.)
Biological– Insects, Bacteria, Fungi, Biochemicals
Chemical– Chemical Pesticides– Pheromones
Chemical Weed ControlChemical 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
Attaining SelectivityAttaining Selectivity
Massive chemical screening programsSelection in crop breeding programs
– Tracy soybean
Non-transgenic methods– Sethoxydim-tolerant corn (tissue culture)– STS soybean
Transgenic technologies (Biotech)
Growth of Biotech AcresGrowth of Biotech Acres% of Total U.S. Acres% of Total U.S. Acres
0
10
20
30
40
50
60
70
80
90
1996 1997 1998 1999 2000 2001 2002 2003
Soybean
Cotton
Field Corn
Biotech Crop UsesBiotech Crop Uses
0
10
20
30
40
50
60
70
80
90
Corn (40) Cotton (73) Soybean (81)
Insects
Herbicide
Stacked
% of Acres
Western Corn Rootworm Adult
Photo credit USDA/ARS
Why the Rapid Adoption?Why the Rapid Adoption?Herbicide Tolerant CropsHerbicide Tolerant Crops
Lower cost of weed control, even with technology fees
Greatly simplified control proceduresHigher degree of weed controlFewer chemical applications = less trips Promotes more sustainable cultural practices
– Less tillage, less compaction, narrower rowsSocietal aspects (pride, landowner acceptance)
Higher degree of control at lower cost
Photo credit USDA/NRCS
And prevent disasters such as this
Photo credit USDA/NRCS
Why the Rapid Expansion?Why the Rapid Expansion?Insect Protection (PIPs)Insect Protection (PIPs)
High degree of control of target speciesSafety to beneficial speciesHuman and environmental safety
– Food/Feed safety– Applicator safety– Wildlife safety
Simplicity of control measures
PIPs aimed at themajor insect pestcomplexes
Photo credit USDA/ARS
Plant-incorporated protectants designed to avoid harm tobeneficials
Photo credit USDA/ARS
What’s the Downside?What’s the Downside?Herbicide Tolerant CropsHerbicide 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 MOAsTemptation to just plant and spray
Weed resistance isa fact of life
Photo Craig Chism, Univ. of TN
What’s the Downside?What’s the Downside?PIPsPIPs
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
Tarnished Plant Bug
Photo credit USDA/ARS
Where do we go from here?
Tacos, Chicken feed,or Plastic??
Photo credit USDA/NRCS
Meat, Milk, or Pharmaceuticals???
Photo credit USDA/NRCS
We’ve only just begun…
Photo credit USDA/NRCS