Yet another group of plant hormones have been identified. We have got used to the wonders of auxins, gibberellins and cytokinins, and have soon understanding of their influence on plant growth. Now we have another group for us to worry about, brassinosteriods.

This hormone is found in almost all plant cells and without it plants would tend to be small and infertile. The influence on flowering and fertility has been investigated in regard to flowering of cucurbits. It has been identified that, in cucumbers, brassinosteriods affect the plants ability to produce ethylene, and are thereby responsible for ‘femaleness’. (Where the male flowers are left on cucumbers the resulting fruits tend to be bitter).

In America research is being carried out into the use differing levels of brassinosteriods to control the size of a plant. There are two obvious ways this can go. One application of the research could be produce grass lawns and hedges that never need cutting. The other could be that large doses of brassinosteriods may be used to boost the growth of crop plants in order to increase yields.