Restricting the growth of blackgrass

Jed Clark is an AHDB PhD student at the University of Leeds, and it’s his goal to assist the agricultural industry in the ongoing fight against that incorrigible weed known as blackgrass.

A potential unforeseen result of the selective breeding perpetrated by wheat farmers, this nuisance plant can actively reduce viable cereal yields. Blackgrass is a weed which thrives in arable land and can unfortunately dominate local resources, but Jed may just have found the solution.

Why blackgrass is an issue

Blackgrass is a severe problem specifically for winter wheat, a crop which sees its root growth grind to a halt during the colder months whilst the more resilient blackgrass continues to proliferate. Due to this prolonged and uncontested period of time, the weed is able to gain a strong competitive advantage. Monopolising space and resources, the blackgrass can easily hinder potential wheat growth.

However, blackgrass never manages to gain quite such a foothold when competing against spring wheat or barley, why is this?

Jed’s research have proven that barley has a considerably larger root system when compared to wheat, making it much better adapted to compete. This gives rise to what Jed refers to as the ‘root growth hypothesis’.

Blackgrass root growth


In his experiments, Jed found that final root biomass was almost double for blackgrass than for wheat, representing a much larger proportion of total plant biomass at 40 percent compared with 17 percent for wheat. Still, the problem of winter wheat being stunted by blackgrass persists with there even being a concern that the chemical root exudates of blackgrass also have a negative impact.

With an increased investment in its own root system and a prolonged period to build said roots, blackgrass growth is a problem in need of an answer. Fortunately, the research being produced at the University of Leeds looks most promising indeed.

Possible solutions

It is Jed’s objective to identify wheat germplasms (such as those seen in barley) which boast increased competitiveness against the common blackgrass. By suppressing the weed with natural means through the use of a competitive crop, this will reduce yield losses and hopefully diminish the economic impact on farmers.

This research into alternative control methods will also help reduce the reliance on typical chemical solutions, a particularly important point as blackgrass is consistently becoming better and better at resisting herbicides.

Jed’s research aims to highlight the advantages behind using competitive crop cultivars as an alternative cultural control method. His future plans for the study include screening winter wheat varieties to identify promising competitive genetic lines. This will allows growers to select from wheat strains from a recommended list based on their ability to compete with blackgrass.

Study and research at the University of Leeds

The University is committed to ensuring those incredible individuals who want to tackle the looming challenges in agriculture, conservation and plant science are equipped with everything they may need. We offer a range of MSc and MRes courses with field trips and research projects designed to provide the experience and skills necessary for whatever lies ahead. As Jed Clark himself put it, “To be in a place where everyone is so dedicated to scientific understanding is very inspiring”.

View a full list of our Masters programmes and research opportunities.