The Science

The proof underneath.

PRO is a research company. The rootstocks began as science — bred, tested and measured — and the case for them rests on evidence. Here is some of it.

A method that changed the crop

Many modern roses grow on a technique PRO’s founder helped create. Stenting — from the Dutch stekken (to root) and enten (to graft) — grafts a scion onto an unrooted rootstock cutting and roots the union in one step. Dr. P. A. van de Pol coined the term in 1979 (Vakblad voor de Bloemisterij) and set the method out in the scientific literature in 1982, with further work in 1986. It remains how much of the world propagates greenhouse roses.

The rootstock reaches the stem

In 2020 PRO commissioned Oritain, a forensic origin-fingerprinting company, to test a striking question: does the rootstock leave a measurable trace in the harvested flower? Under controlled conditions — same greenhouse, substrate, feed and age — roses on PRO and Natal Briar rootstocks were fingerprinted for their trace-element chemistry.

The pilot found that the rootstock shapes the chemistry of every part of the plant, including the cut stem — clearly enough to tell a stem grown on a PRO rootstock from one grown on Natal Briar. It is early work, a pilot that needs further validation before it becomes a verification tool. But the direction matters: the root system’s signature travels all the way to the flower — pointing to a way of protecting growers and breeders against unauthorised propagation.

Pilot study by Oritain Global Ltd, 2020.

Two measurements, one answer

There is a quiet confirmation in that work. PRO’s own leaf analysis had already shown roses on ProTatu/PRO3 take up more copper and molybdenum than on Natal Briar. Oritain, working blind and on another continent, found copper and molybdenum among the very elements that distinguish the stems. Two methods, two datasets, the same fingerprint.

Less stress, healthier plants

Because the crop establishes and feeds more easily on a PRO rootstock, it carries less stress — and growers report fewer stress-related problems, including reduced Agrobacterium. A field observation, consistent across farms, not a laboratory claim.

Silent progess in the field

Our breeding and research programmes are very much alive! New candidates are in trial now, measured the way everything at PRO is measured: side by side, in real houses, counted and analysed. We’ll report when we are sure we found new exciting facts.