A pest like whitefly has a direct impact on the resilience of a crop. It's not just the pest's feeding on the crop that is harmful; whitefly also poses a risk of virus transmission. Worse still is the likelihood that other diseases and pests will strike – as a grower, you certainly want to avoid that!
A healthy plant is a basis for good growth and production, so it should be no surprise that an attack by a pest like whitefly will undermine the crop. The extent will depend on the species and variety, but the fact remains that a plant that has been attacked will be less 'happy' and more susceptible to problems such as mold and root diseases.
Viruses as a bonus
Whitefly is also capable of transmitting viruses, with the tobacco whitefly having a notably bad reputation. The transmission of viruses is a major concern, considering that plants cannot fight back. Once a crop has to contend with a virus, it will be more susceptible to other diseases and pests.
Furthermore, an element such as nitrogen can also harm a plant's resilience. While the plant may look healthy on the outside, the nitrogen is actually hard at work inflating its cells, weakening the plant and creating an 'obese plant.'
The result will be a plant that is more attractive to pests like whitefly – it's not only the plant that likes nitrogen; it's a tasty snack for whitefly as well. Naturally, this will increase the size of the whitefly infestation. In short, nitrogen-rich plants are a real treat for whitefly!