TY - JOUR

T1 - Laser weed seed control

T2 - challenges and opportunities

AU - Andreasen, Christian

AU - Vlassi, Eleni

AU - Salehan, Najmeh

AU - Johannsen, Kenneth S.

AU - Jensen, Signe M.

PY - 2024

Y1 - 2024

N2 - Farmers are greatly interested in reducing weed seeds in their fields to avoidunnecessary weed infestation. Autonomous vehicles equipped with plantrecognition systems and lasers can be used to control weed plants and maytherefore be used to replace or supplement herbicides and mechanical weedcontrol. However, less is known about the ability of laser to control weed seeds.In this study, seeds of weeds (Alopecurus myosuroides, Anisantha sterilis, Avenafatua, Centaurea cyanus, Silene noctiflora) and crops (wheat (Triticum aestivum),maize (Zea mays)) were exposed to increasing dosages of laser energy. Thespecies represented dicots and monocots with different seed sizes andmorphology. We used a thulium-doped 50 W fiber laser with a wavelength of2 μm and a diameter of 2 mm developed for weed control. The seeds wereexposed to laser directly on the seed surface or after been covered with soil (2.5and 5 mm). Small doses of energy (0.4 J mm−2 and 0.8 J mm−2 ) affected thegermination ability of small seeds (S. noctiflora and C. cyanus) when the seedswere irradiated directly on the seed surface, and they were completely burned atthe high doses (8.0 J mm−2 and 15.9 J mm−2 ). However, there was not a clearrelationship between seed size and sensitivity to laser dose. Additionally,increasing the laser dose on the seed surface resulted in increasing infection offungi. Seeds covered with soil were not affected by the laser treatments except C.cyanus seeds. Controlling large seeds on the ground while weed seedlings arecontrolled with laser robots seems realistic in the future. However, dosageshigher than 50 J (~15.9 J mm−2 ) is necessary to control large seeds.

AB - Farmers are greatly interested in reducing weed seeds in their fields to avoidunnecessary weed infestation. Autonomous vehicles equipped with plantrecognition systems and lasers can be used to control weed plants and maytherefore be used to replace or supplement herbicides and mechanical weedcontrol. However, less is known about the ability of laser to control weed seeds.In this study, seeds of weeds (Alopecurus myosuroides, Anisantha sterilis, Avenafatua, Centaurea cyanus, Silene noctiflora) and crops (wheat (Triticum aestivum),maize (Zea mays)) were exposed to increasing dosages of laser energy. Thespecies represented dicots and monocots with different seed sizes andmorphology. We used a thulium-doped 50 W fiber laser with a wavelength of2 μm and a diameter of 2 mm developed for weed control. The seeds wereexposed to laser directly on the seed surface or after been covered with soil (2.5and 5 mm). Small doses of energy (0.4 J mm−2 and 0.8 J mm−2 ) affected thegermination ability of small seeds (S. noctiflora and C. cyanus) when the seedswere irradiated directly on the seed surface, and they were completely burned atthe high doses (8.0 J mm−2 and 15.9 J mm−2 ). However, there was not a clearrelationship between seed size and sensitivity to laser dose. Additionally,increasing the laser dose on the seed surface resulted in increasing infection offungi. Seeds covered with soil were not affected by the laser treatments except C.cyanus seeds. Controlling large seeds on the ground while weed seedlings arecontrolled with laser robots seems realistic in the future. However, dosageshigher than 50 J (~15.9 J mm−2 ) is necessary to control large seeds.

U2 - 10.3389/fagro.2024.1342372

DO - 10.3389/fagro.2024.1342372

M3 - Journal article

VL - 6

JO - Frontiers in Agronomy

JF - Frontiers in Agronomy

SN - 2673-3218

ER -