Module 3

Question 1

Noncompetitive Losses Due to Weeds

Answer 1

• Decrease in Land Values
• Dockage if crop contains too many weed seeds
• Health problems like rashes and allergies

Question 2

Benefits of Weeds

Answer 2

• Soil Cover
• Pollinator Habitat
• Edible

Question 3

When 8” weeds were taken out of corn crop that was at about V6 one month later

Answer 3

Corn in the treated area was stunted compared with the surround crop

Question 4

When looking at rice and barnyard grass densities, yield loss

Answer 4

• was greater at high barnyard grass density, but was less if there was high rice density

Question 5

Yield Losses Will Vary With

Answer 5

• Crop Species
• Crop Row Width
• Weed Species
• Weed Density
• Corp Seeding Rate

Question 6

Comparing Weed Development in Corn and Soybean, the Most Competitive Crop, Later in the Season is

Answer 6

Soybean

Question 7

Allelopathy is an example of

Answer 7

Indirect Competition

Question 8

Yield Loss Due to Weeds

Answer 8

• Are usually minimal if the crop is beyond the critical weed free period
• Is dependent on the crop, crop growth stage and weed species present
• Are usually greater if the weed is present when the crop emerges