What method can be used to prevent crop injury aside from monitoring weather conditions?

Applying herbicides during optimal conditions is crucial for preventing crop injury because it ensures that the herbicide works effectively while reducing the risk of adverse effects on the crops. Optimal conditions typically refer to factors such as temperature, humidity, and wind speed that can influence the herbicide's performance and its potential to cause harm to the crops.

When herbicides are applied at the right times, such as during periods of calm weather and suitable temperatures, the likelihood of drift or evaporation that could lead to crop damage decreases significantly. Additionally, optimal application conditions can enhance the herbicide's absorption by the target weeds, ensuring efficacy without overexposing the crops.

The other methods mentioned, like increasing herbicide dosage or using multiple brands, do not necessarily improve safety for the crops and could actually increase the risk of injury or create herbicide resistance. Limited application times may not account for the broader environmental conditions that impact safety and efficacy, hence monitoring those conditions in conjunction with applying at optimal times is advisable for the best outcomes in crop protection.