According to FAC 6902, nursery stock must be commercially clean with respect to what?

The correct answer focuses on nursery stock being commercially clean specifically concerning pests of general distribution. This means that when managing nursery stock, it is crucial to ensure that the plants are free from common pests that could easily spread and cause harm to the plants or the environment.

Keeping nursery stock clean from such pests is essential in promoting healthy plant growth, minimizing crop losses, and preventing the transfer of invasive species. This requirement helps maintain the integrity of the nursery stock market and supports overall agricultural health, as diseases and pests can economically impact both growers and consumers.

While soil quality, specific plant types, and water usage are important factors in nursery management and overall plant health, the regulation emphasizes the cleanliness from pests to prevent widespread infestations and ensure that the plants are in optimal health for sale and planting.