A nitrogen deficiency causes leaves and plants to be light green or yellow. The vine may also suffer from slow, inadequate growth and produce few flowers. A manganese deficiency causes older leaves to turn yellow and develop dead brown spots.

Root-knot nematodes, microscopic parasitic worms, infest the roots of the beans and prevent them from absorbing nutrients. The leaves yellow and the plant's growth is stunted. Soil solarization when the soil is cleared kills nematodes.
Mosaic disease affects beans by producing mottled yellow patches on leaves and yellowing of plants. Planting mosaic-resistant varieties is the only solution for the virus. Bacterial blight causes spreading yellow spots on leaves. Keeping leaves dry can help prevent fungal diseases. Bean rust symptoms include yellow leaves with brown dust on the undersides. Rust infects plants in cooler weather. Multiple applications of sulfur spray can control the fungus and should begin when rust first appears.