24 November 1995

Cereal control goes natural?

NATURAL products from the bacteria Pseudomonas fluorescens could provide a novel source of potent new herbicides, claim Zeneca scientists working in the UK and Canada.

The herbicidal activities of derivatives of pseudomonic acid were first reported in 1994. Now one of those, monic acid, has been shown to be particularly effective against broad-leaved weeds in cereals.

Field trials in Europe have not been as promising as in Canada. Nonetheless a 250g/ha application of the derivative mixed with an oil adjuvant outperformed mecoprop-P for cleavers, mayweed, ivy leaved speedwell and field pansy control.

Best control was achieved from applications when weeds were relatively small in warm, bright conditions.

Crop safety was generally good in winter cereals.

A low environmental impact and the promise of another new mode of action give the material "considerable potential" says Zeneca. &#42