August 2011 issue of the Cornell Flower Bulb Research Program Research Newsletter:
Most Dahia growth regulator recommendations are based on A-Rest. Initial studies indicated that Bonzi and Topflor offer much better growth control at a lower cost, but there is a general lack of information concerning their use. This work was conducted to highlight the potential for use of these products on Dahlias grown in larger (“nursery”) containers. As an initial experiment, we learned quite a lot about Dahlias (and realize we have a lot more to learn!). Plants generally grew well, but by the end of the experiment several had succumbed to various root rots. Also, plants were variable, but as pointed out above, this was to be expected.