Another way to get rid of this weed is to make wine from it.
The common grass burr (Cenchrus incertus) and sand burr (Cenchrus echinatus) are a major nuisance in Texas and elsewhere. The half-dozen to a dozen sharp spikelets on each seed stalk grab whatever passes by. My English Springer Spaniel's hair has been so loaded with them she could not lie down. There are numerous strategies for getting rid of this unwanted weed-grass. I divised another. Make wine of their spiked seeds.
I picked the seed stems while the seeds were still green and tossed them into a bucket. When my back ached sufficiently, I went inside and used a fork's tines to strip the spikelets off the stems. When done, I made two more trips outside to "harvest" more burrs. When at last I had a quart, I placed them in a 2-quart pan and added a quart of water. I stirred to dampen them, then put on the lid and brought them to a boil. Twenty minutes later I strained them out and saved the dark green water. I assumed some tannin was present, but no sugar or acids. The recipe developed from those assumptions. The finished wine was light straw, without any hint of green.
Bring sand burrs to boil in 1 qt water for 15-20 minutes. Strain and discard burrs, but retain water. Add sugar, tannin, acid blend, and yeast nutrient and stir well to dissolve. Add grape concentrate and remaining water. Cover and set aside to cool. When room temperature, add activated yeast and recover. Stir daily until vigorous fermentation subsides (7-10 days). Transfer to secondary, top up and fit airlock. Ferment to absolute dryness (30-45 days). Rack into clean secondary, top up and refit airlock. Rack after 60 days and again 30 days after that. Stabilize with potassium sorbate and crushed Campden tablet (stirred well), then sweeten to taste. Wait 30 days and rack into bottles. This wine was very drinkable after two months but absolutely heavenly after a year. [Author's own recipe]