Weed Interferance Flashcards
Define the term interference
Changes of environment bought about by proximity of individuals
Different types of interfernce
Allelopathy and Competition
Competition
2 or more organisms seek common resource whose supply falls below their combined demand
Allelopathy
Chemical affect of one species on another
\Production of toxins
Example of allelopathy
Vulpia residues reduce DM production of winter crops
Resources plants compete for
Sunlight
Water
Nutrients
Space
What space is most competition saught
Shoot competition has greatest effect
Yield loss curve
Why isn’t it linear
Linear curve doesn’t occur as weeds suffer intraspecific competition
Other than weed density list five other factors related to the crop or weed that contribute to the size of the yield loss
Weed Species competitive nature Crop Density Crop Competitiveness Timing of weed emergence Timing of weed control
Weed Species competitive nature
Skeleton weed Wild oats Broome Grass Rye Fumitory
Effect of increased crop density on weeds
Increase density = increase comp
Crop species Competitiveness
Oats=cereal rye=triticale
Canola
Spring wheat = Spring barely
Field peas=lupins
Timing of weed emergencg
Emergence of weeds before crop has massive yield implications
Timing of weed control
Critical period- when weeds and crop actively compete for same resources
Outline five key elements in conducting an IWM program
Know the problem Plan the Strategy Implement the strategy Monitor and record Review
