ABSTRACT
All agrochemicals will damage crops under some conditions, although a major overdose is the only likely cause of injury by the majority of products. Herbicide damage always looks appalling and may seem catastrophic to the grower, but many crops have remarkable powers of recovery, the eventual loss in yield being frequently much less than feared. For herbicides which act by inhibition of photosynthesis risks, when the herbicide is fully activated, are increased by sunny or windy weather, which induces rapid transpiration and uptake of herbicide. The triazines, triazinones, and substituted ureas are examples of this group of herbicides. Tri-allate, one of the thiocarbamate group of herbicides, causes characteristic damage when wheat or barley is sown too shallowly. The position of residues in the soil relative to the seed of the succeeding crop is another factor affecting the possibility of damage. Drift of an herbicide into a neighboring field is a common cause of crop injury.
