Cassava (Manihot esculenta) is an important storage root crop in tropical and subtropical parts of the world. Breeders are trying to improve critically important traits such as resistance to diseases, but their progress is hampered due to its lengthily breeding cycle, poor flower set, and variations in flower timing. Studies will be reported on the use of the plant growth regulator silver thiosulfate (STS) to improve flower development and longevity. STS treatments provided significantly longer flower retention time, more floral buds, and longer inflorescence stalks compared to the water control. Studies indicated that STS prevents ethylene-induced floral senescence and abscission. STS alters ethylene production due to interference with a negative feedback loop. To limit effects of STS phytotoxicity, a technique was developed whereby STS is applied for a limited time to a localized region where flowers develop. These studies suggested that using a cotton swab method would help to improve cassava flowering set, and also alleviate the phytotoxicity damages on the plants.