How does a "seed potato" farmer select cultivars that resist disease and pests?

A seed potato farmer selects cultivars that resist disease and pests by identifying superior plants in the field and using them for propagation. This practice, known as "selection breeding," involves observing the performance of various potato plants in the field, focusing on traits such as disease resistance, yield, and adaptability to local growing conditions. By selecting plants that exhibit desirable characteristics, the farmer can improve the overall quality of the crop. This method also allows farmers to choose cultivars that have shown resilience against specific local diseases or pests, thus enhancing the chances of a successful harvest.

Utilizing seeds from last year's harvest does not ensure that the plants will exhibit resistance to diseases or pests, as those issues can vary significantly from year to year. Purchasing seeds from a commercial supplier can provide an initial quality assurance and certain disease-resistant traits but does not allow for the selection process based on local conditions. Random selection of plants does not apply any criteria for resistance, which can lead to the continuation of susceptible traits within the population. Thus, the thoughtful selection of superior plants is crucial for developing a resilient crop that will thrive in the farmer's specific agricultural environment.