Weeds with underground Rhizomes (like Imperata cylindrica or Sorghum halepense) are highly resistant to standard tillage, as broken rhizome fragments can regenerate into independent plants.
Step 1: Understanding the Concept:
Perennial weeds are difficult to manage because they propagate through both sexual means (seeds) and vegetative structures (rhizomes, stolons, tubers, or bulbs) that can survive tillage and harsh environmental conditions. Step 2: Detailed Explanation:
Let us analyze the propagation of Imperata cylindrica:
- Imperata cylindrica (commonly known as cogongrass or thatch grass) is a highly invasive perennial grass weed.
- Its primary method of vegetative propagation and survival is through its extensive, tough, and sharp-pointed underground rhizomes (Statement A).
- These rhizomes form a dense mat in the soil, storing large amounts of carbohydrates.
- If the above-ground foliage is cut, burned, or tilled, dormant buds on the rhizomes quickly sprout to produce new shoots.
- Tillage can actually spread the weed by cutting the rhizomes into smaller fragments, each of which can grow into a new plant.
- While some weeds propagate via stolons (like Bermuda grass, Cynodon dactylon), Imperata cylindrica relies primarily on its underground rhizomes for spread and survival. Step 3: Final Answer:
The correct option is (A).
