Preventive measures and biological control methods should be preferred for protecting crops because excessive use of chemicals can cause harm to the environment. These chemicals are also poisonous for plants and animals. These chemicals are absorbed by the plants along with water and minerals from the soil and are taken by aquatic plants and animals as well. Preventive method are those which can be done beforehand to prevent the loss. These measures include proper soil and seed preparation, timely sowing of seeds, intercropping and mixed cropping, usage of disease resistant crops, etc.

On the other hand, biological control methods involve the use of bio-pesticides that are less toxic for the environment as they are made from organic material. Therefore, both preventive measures and biological control methods are considered eco-friendly methods of crop protection.