Monday, 06 September, 1999

By FWi staff

FARMERS could improve yields and economic performance by variety typing and selecting the best variety for a given site, according to Home Grown Cereals Authority (HGCA) funded research.

ADAS and the University of Nottingham assessed the value of using amount of water soluble carbohydrates in stems (WSC) as a method of physiological variety typing in winter wheat and barley.

The relationship between water soluble carbohydrate, other indicator traits and the drought tolerance of six winter wheat varieties was assessed.

The experiment took place at ADAS Gleadthorpe in three dry years (1994-1996).

Varieties with high levels of WSC showed evidence of being better able to withstand late season drought in 1994 due to a buffering effect of these reserves.

With the drought that was experienced in 1995 and 1996, the more tolerant varieties were those that withstood drought better before flowering and maintained stem reserves close to levels observed in fully irrigated controls.

Ability to amass higher amounts of WSCs in these seasons contributed to observed drought tolerances.

The varieties which performed best overall in a drought were Rialto and Mercia which only saw losses of about 2.7t/ha.

Haven and Riband came out worst experiencing yield reductions as high as 3.5t/ha.

Following this research the National Institute of Agricultural Botany (NIAB) now assesses soluble stem carbohydrate reserves in all trials of winter wheat for the Recommended List.

WSC levels in stems of 13 winter barley varieties were measured in crops grown at ADAS Rosemaund and ADAS High Mowthorpe.

Mean WSC levels ranged from 2.33 tonnes a hectare in Halcyon to 1.30 tonnes a hectare in Rifle.

Winter barley varieties had lower stem WSC levels than winter wheat varieties tested in recent seasons but the range of values was mainly similar.

It seems likely that barley varieties, like wheat, differ in their potential tolerance of late-season drought stress, according to the research.

Selecting winter barley varieties on the basis of variety typing for a wider range of characters could deliver additional returns ranging from £10 to £187/ha as a result of improvements in nitrogen utilisation, tillering, weed suppression, drought and take-all tolerance, late season disease control and lodging resistance.

Further information can be sought from the HGCA at Caledonia House, 223 Pentonville Road, London N1 9HY.