Emeritus, University of California, San Diego, CA
The intentional manipulation of wild plants to become desirable crops was the beginning of agriculture some 10,000 years ago. Along with this beginning came weeds; unwanted plants that prospered in the same human-created environments. Weeds are therefore just as much a part of our domestic culture as the crops. So the history of weed control technology is co-existent with the history of agricultural technology. If you search the internet for the history of agriculture, you will find lots of information. If, however, you search the internet for the history of weeds, you will be disappointed by the lack of literature and...
I recently met with a grower who wanted to put down a preemergent herbicide to get ahead of winter weeds. The crop he is growing has very limited choices but Surflan A.S. could be used. Surflan and other members of the dinitroaniline class of herbicides act by disrupting cell division in the roots of germinating seeds and resulting in death of the very young seedling before it even reaches the soil surface.
However, to be effective the herbicide needs to be where the root radicle of the seeds are so it either has to be incorporated mechanically or moved into the soil through rainfall or irrigation. The commonly accepted term for this is “activation”.
From the Surflan A.S. label:
- Author: Richard Smith
The development of improved cultivation technology for row crop production has been an active area of research, and has made significant progress in recent years. Currently, standard cultivation removes weeds from the majority of the bed using sweeps, knives, coulters and blades. Typically a 4-inch wide band is left around the seedline. Weeds in the uncultivated band are typically removed by hand, and the density of weeds that occur there, determines how laborious and costly subsequent hand weeding will be.
There is technology to remove weeds from the seedline and it generally falls into two categories: 1) blind cultivation and 2) computer assisted cultivators. Implements used for blind cultivation are not guided by a...