Finding successful growth regulator alternatives for chlormequat might not be quite as straightforward as you would think, Velcourt‘s Keith Norman warned.

Chlormequat was currently going through the European re-approvals procedure and there was some uncertainty over whether it would be approved on to the Annex 1 listing, he explained.

The firm demonstrated some alternative programmes in its demonstration area at Cereals, but while initial shortening of wheat crops resulted, alternative products Moddus and Canopy, when used without chlormequat, resulted in significant “bounce-back” of the crop, he noted.

“They are effective at stopping growth, but they work in four different points. That puts an enormous pressure on crop growth. It is a bit like clamping a hose-pipe. When you release the pressure you get a sudden spurt of growth,” he explained.

Using a single high dose of Canopy at GS30-31, rather than two smaller splits, had resulted in uncontrolled late recovery growth, for example, he said.