Long used in protected bedding and pot plant production, the growth regulator Bonzi, containing paclobutrazol, controls both flower size and flower stem length of maturing plants and is valuable for holding crops back when necessary to meet marketing schedules.
Leaf size on treated plants is smaller, and colour improved – including of red poinsettia bracts – but leaf number, branching and root growth are unaffected. Despite all the recent advances in crop nutrition and environmental control, crop growth and development are still largely influenced by the weather. Everyone is looking to reduce the use of chemicals in ornamental crop production but at the same time, growers are having to meet ever tighter plant specifications and marketing schedules.
It’s only by careful integration of plant growth regulators into the production regime that you can achieve the speed or precision of control needed. The aim should be to maximise the effectiveness of applications, for example to schedule a crop or hold back a batch in response to changes in demand or unseasonal weather.