Rust

General Caused by Uredo cajani. Disease severity increases with the onset of flowering. Dense planting and the formation of a closed canopy provide a microclimate favorable for disease development. Light rain, wind and cloudiness encourage disease development. Symptoms Dark brown raised pustules full of uredia on the lower leaf surfaces (Figure). The surface of the leaves at first is tinged with slight yellowish spots that coalesce and gradually darken into brown as the plant matures. Infected leaves desiccate and drop off. Extensive defoliation occurs in severe infections. Management Avoid sowing pigeonpea close to bean fields. Rotate crops to reduce the chance of pathogen survival. Keep pigeonpea areas weed-free as weeds serve as alternate hosts of rust pathogen. Maneb 3 g per liter of water is effective.

Dark brown raised pustules on the lower surface of leaves.