Researchers at Rothamsted Research have shown that careful selection of the first wheat variety in a new cropping cycle can reduce take-all and increase yields in the second crop variety.
These benefits are said to be irrespective of the second variety or its susceptibility to this fungal pathogen. And though the findings relate to short rotations, in which the type of crop is changed after two harvests, the benefits seem to continue for subsequent harvests, according to the researchers.
Dr Vanessa McMillan, plant pathologist at Rothamsted Research, who led the study says: “In rotation field experiments, we demonstrated the considerable and lasting impact of the choice of the first wheat variety on root health and the yields of the second wheat.
“There was a consistent reduction in take-all disease and a grain yield advantage of between 0.2 and 2.4 tonnes per hectare (or up to 25 per cent of average UK yields),” adds Dr McMillan.
“The results were consistent across multiple field seasons and sites.”
The research team had already identified and reported a new genetic trait in wheat, take-all inoculum build-up (TAB); in spite of wheat’s high susceptibility to take-all disease, there are low TAB varieties that minimise presence of the pathogen in soil.
The team’s latest findings show that using one of these low TAB varieties in year 1 of a cycle generates the benefits for the second crop. The team is now investigating how lasting these benefits are in subsequent crops.
As part of the latest work, the team sampled commercial wheat varieties across a range of field sites from the AHDB Recommended List (RL) that demonstrated variation in TAB properties of modern wheats currently being grown by farmers in the UK.
Dr McMillan says: “While there was evidence of significant interaction between the varieties across the trial sites, we could still identify a small number of low TAB varieties across all sites.”
Rothamsted suggests that RL varieties Grafton, Cordiale and Crusoe would have good potential as first wheat varieties to reduce take-all risk in the second wheat crop.