Cassava is the fourth largest staple crop in the world, and it serves as a main carbon source for human nutrition in Africa, South America, and Southeast Asia. However, its poor flower set and lack of flowering synchrony makes it hard to breed improved genotypes with higher production and superior qualities. Previous findings indicated that applying silver thiosulfate (STS) could improve cassava flower retention and might be useful in cassava breeding. However, at the rates used it might induce severe phytotoxicity on the plants, and there is concern silver may accumulate in the soil. The goal of this research was to find better strategies to apply STS and reduce plant phytotoxicity. Experiments with ethephon showed that ethylene was responsible for cassava flower abortion and senescence. STS inhibited ethylene signaling thus protecting the flowers from abortion and senescence. Compared to wide-scale spraying of STS to mature leaves, localized STS application to the apex was equally effective for flower retention, and it requires less silver. To develop an optimal protocol, tests were conducted to find 1) the best timing for STS applications; 2) the number of applications required for better flowering; 3) the best placement for STS application; and 4) the best concentration for STS application on cassava. Overall, the findings indicate that optimal STS treatment is when it starts at least several days before bud appearance, and with a continued supply during flowering. STS application to the young leaves in the apex avoids excess application and phytotoxicity. STS dosage requires optimization: it needs to be sufficiently high for substantial flowering benefit, and low enough to avoid phytotoxicity. These findings indicate that STS could serve as a potentially valuable tool for cassava breeders in managing flowering