Laser-optics-based method to suppress Mikania micrantha growth

Area of Science:

• Plant Science
• Laser Technology
• Invasive Species Management

Background:

• Mikania micrantha is an aggressive invasive species with rapid asexual and sexual reproduction.
• Current control methods are neither effective nor economical for managing Mikania micrantha spread.

Purpose of the Study:

• To develop and evaluate a high-energy laser-based method for suppressing Mikania micrantha growth and spread.
• To optimize laser parameters for maximum damage to the plant's internal stem tissues.

Main Methods:

• Analysis of Mikania micrantha stem tissue absorption spectrum to select an optimal laser wavelength (455 nm blue laser).
• Investigation of laser beam size and configuration (single or dual beams) to enhance stem tissue damage.
• Application of cumulative laser energy to hydroponically grown Mikania micrantha samples.

Main Results:

• A threshold penetrating optical intensity of 3.1 W/mm² was determined.
• Optimal laser irradiation (15 Joules cumulative energy, 0.81 mm × 0.74 mm beam size) achieved 97.5% inner stem tissue damage.
• All laser-treated Mikania micrantha samples withered within 30 days.

Conclusions:

• High-energy laser application is a viable method for controlling Mikania micrantha.
• Targeting the stem's vascular bundle and medulla with a 455 nm blue laser effectively inhibits growth.
• Applying this method before the flowering season can prevent Mikania micrantha reproduction.