Similar methods have been used since at least the 1950’s that do not require lasers. You can search ‘cultivator tractor flame weeder’ on youtube to see some of the more exciting examples. Flames are not required either. ‘Basket weeders’ are another neat type to look up. There are plenty of mechanical implements that due the same job. All of these implements just require that crops be planted in perfectly straight rows so that all spaces around the growing crop can be disturbed to destroy weeds.

Cultivator tractors and an endless array of ingenious attachments were supposed to be the way of the future until the chemical industry bloomed and took over the agricultural sector. They are now relegated to small scale organic farmers which is a shame.