9 February 1996

Strong thumbs-up given for new PGR

A NEW plant growth regulator got a firm thumbs up from a leading agrochemicals supplier last week.

Speaking at a Banks Agriculture farmer conference near Huntingdon the companys senior technical manager Bob Mills described the lodging control of Moddus (trinexapac-ethyl) as "second to none."

Although stem shortening in wheat is not pronounced, stem thickening is very noticeable, he said. "This showed in our own trials as well as Cibas. The stems were very stiff with very much thickened walls."

Trials on the product intensified following a "look-see" trial at Banks Eynsbury site in 1993/4. Moddus plots stayed standing while plots all around lodged, including those treated with other pgrs. Last years trials evaluated the material in Rialto, both with and without chlormequat and under different nitrogen regimes. Although lodging was not a problem, yield improvements were observed, particularly where Moddus was split between GS 29 and 31.

"Even without lodging there are yield benefits – that may be to do with tiller manipulation.

"But I think root development is involved too. Chlormequat has this effect at early timings and I think Moddus does so even more," Mr Mills said.

That view was supported by field observations near Cambridge. "The one hectare trial plots treated with split rate Moddus were visibly greener all though the season, probably because of better rooting during the drought, helping the plant use nutrients and what water there was."

In winter barley Moddus provides good lodging control, and seems to have a greater effect on straw shortening, particularly when used late, noted Mr Mills. That could be a particular benefit for growers faced with the risk of crop damage from using Terpal (2-chloroethylphosphonic acid + mepiquat chloride) late, added crop protection director Steve Wolff.