Final answer:
The most effective methods for controlling cabbage aphid populations involve biological control and companion planting with specific plants.
Explanation:
Controlling Cabbage Aphid Populations:
- Enclosed Setting: In an enclosed setting like a greenhouse, the most effective method for controlling cabbage aphid populations is using biological control through the introduction of ladybugs or lacewings. These natural predators help keep aphid populations in check without the use of harmful chemicals.
- Outdoor System: In an outdoor system, employing companion planting with marigolds is effective. Marigolds release a scent that repels aphids, providing a natural defense mechanism.
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