Alternatives to Pesticides Flashcards
Why is there a need for ecological weed management?
limited development of new chemistries
increase in resistance
increased public pressure to decrease risks
increased research and knowledge of weed/crop ecology
What is a post emergence approach?
treat after the weed has appeared
hard to do without chemicals
Why is canopy closure critical?
it’s critical to control up to this point, after this point weeds germinating will have little impact on yields
“critical weed free period”
What are some considerations with using IPM tactics?
multiple species compete for same resources more difficult to predict economic thresholds weeds tend to start in patches weed seed bank
What are tactics for ecological weed management?
crop rotation, hand weeding, conservation of natural predators, proper timing with mechanical options, selective weed harrowing (weakly rooted and climbing species), random distribution, trap crops, monitoring, varietal resistance
What are the primary insect pests of concern for sweet corn?
flea beetles, European corn borer, fall army worm, corn ear worm
What are flea beetles?
disease transmitter - carry Stewart’s wilt
spray above threshold
problem early in the season
What is European corn borer?
moth lays eggs on leaves
larvae burrow through leaves into plant stem
cause serious damage to ear - unmarketable
What is fall army worm?
causes very visible damage to plant leaves
generally recover from feeding damage
main concern - damage to growing ear
greater problem in fresh market
What is corn ear worm?
moth lays eggs on silks
larvae feed on corn ear
damage can make it unmarketable
can avoid pest by harvesting earlier (tradeoff)
What are economic thresholds?
level of infestation at which cost of treatment equals cost of taking no action
What is IPM?
establishment of economic threshold
quantify population of pest and demonstrate crop:pest interaction
optimizes use of chemical, biological, and cultural controls
