Farmers have been waging a battle against pests since the beginning of time. Early accounts of pesticide use give credence to the idea that man has been locked in a perpetual fight with nature. As man looks to the future of farming and the development of agrochemical products to aid in the quest to eradicate pests from the fields, a startling discovery has been made: pests have adapted to most pesticides. Pests have evolved over time, rendering the use of many pesticides ineffective and leading to the development of a different method of pest removal.
Evidence for Adaptation
Fossilized weeds have preserved the evidence: specific genotypes have changed to avoid traditional pest control practices. Weed populations demonstrate the effect of these changes in the timing of reproduction and seed size, adaptation designed to resist the effect of winnowing. A process in which famers eliminated weed seeds from grain seeds, winnowing was part of the planting process. Farmers would save a small amount of seed to use for the following year’s crop. The weeds, however, found a way to infiltrate that process by producing seedlings that looked like crop seeds. Even farmers using hand winnowing were unable to remove all of the look-alike seeds.
Insect and microorganism adaptation is more challenging to trace. However, there is evidence that crop breeding produced strains of crops resistant to pest attacks. In turn, the pests continued to evolve in an effort to survive. Traces of fungal genotypes have been found on fossilized food supplies, demonstrating the continued existence of crop pests. Recent examples of pest adaptation may provide an indication of how pests survived in previous generations: a corn pest adapted to the yearly crop rotation by encasing its eggs in a durable casing that survived until the following year’s planting. A similar pest that feeds on corn has managed its adaptation by laying its eggs in the soybean fields that will be planted with corn in the following year.
As man developed pesticides to manage pests, the pests continued to adapt. In a matter of growing cycles, pesticides were no longer effective in their control of pests, forcing farmers to increase usage rates and ultimately seek stronger and more effective methods. Historically, biological pest control methods could adapt with the pests, creating a race of sorts, with each group attempting to surpass the other. The development of synthetic pesticides, however, has taken pesticides out of the race. Synthetics are not able to adapt with the pests, forcing man to continually generate new pesticides that will keep pace with the adaptation. Evidence shows that pests develop a resistance to control measures within three years, creating an endless cycle of need for stronger control agents.
There are two phases to pesticide adaptation. The first phase involves increasing the dose and frequency of application. An unintended side effect of this phase, however, is an increased level of pest resistance, as well as greater damage to the environment. The second phase involves the development of new pesticides.
Records show that an astonishing 500 insects and 150 pathogens have developed resistance to at least one form of pesticide. This continual adaptation has forced pesticide companies to move to phase two of pesticide adaptation. Agrochemical companies are at the forefront of pesticide adaptation. With improved technologies and advanced science, these companies are developing new pesticides that limit environmental impact and have a long-term effect on pests.
History has shown that in the absence of new pesticides, pests that have developed resistance can have a lasting and detrimental effect on crops. The cotton industry in Nicaragua, for example, collapsed due to the aggressive pests that plagued the fields. Some individuals believe that the aggressive treatment of pests will result in a more aggressive pest. However, the development of powerful, synthetic pesticides may negate that theory. Many of today’s pesticides are more toxic than their predecessors and more selective in the pests that they affect. Due to the use of stronger pesticides, it is unlikely that pests will be able to adapt quickly.
New pesticides are also more singular in focus. Traditional pesticides targeted a wide range of pests. Today’s synthetics may zero in on a particular pest, and they are more efficient in eradicating it.
The Future of Pesticides
As agrochemical companies continue to develop pesticides, they are using new and improved methods of increasing viability in their products. Pesticide-resistant management is a new field within the agrochemical industry that deals primarily with the development of products that resist adaptation by pests. Researchers carefully monitor resistance strains and work to develop strains of pests that can be used as control groups or as target opportunities for new classes of pesticides.
Farmers are facing new challenges in meeting the demands of the world’s growing population. As the demand for food increases and the number of available growing areas decreases, farmers must be vigilant in preserving crops and mitigating losses as a result of disease and pests. Agrochemicals will continue to play a key role in this fight.