The source lists chemical treatments for leafhoppers, aphids, whitefly, ash weevils, leaf spot and powdery mildew (neem-based azadirachtin is listed for ash weevils). Choose any product only with your local Horticulture or Agriculture Officer.
Follow the instructions on the product label. Consult your local Agriculture Officer before use.
Pending expert review
Source
Crop Production Guide – Horticulture Crops 2020 (Directorate of Horticulture and Plantation Crops, Tamil Nadu & Tamil Nadu Agricultural University (TNAU)), Cluster bean – Plant protection, pp. 107–108