Unraveling the Blackgrass Mystery

You've likely experienced the heightened presence of blackgrass in the 2022/23 season.

Blame has been placed on the absence of germination in the dry conditions of the previous autumn and the earlier drilling of wheat. However, head of agronomy, Colin Lloyd, suggests that the late winter and early spring weather played a more significant role, impacting crop competition.

Weather's Impact on Crop Competition

The weather narrative unfolds with a dry February followed by an exceedingly wet March, effectively a lost month. The mistiming of nitrogen fertilizer due to the challenging weather, coupled with lower temperatures, led to slow-growing crops. Blackgrass, finding less competition, flourished in the absence of crop competition, resulting in increased tillering and, consequently, more ears this summer.

Lack of Spring Crop Competition

Winter barley, for instance, experienced nearly three times the anticipated blackgrass heads, ranging from 90-255 ears/sq m. Colin notes that adverse conditions hindered its early spring growth, impacting its hybrid vigor. This contrasted sharply with the previous year, where it yielded over 10t/ha regardless of cultivation methods.

Similarly, direct-drilled wheat showed thinner growth and witnessed up to 209 blackgrass ears/sq m. Spring barley struggled to establish itself, showcasing blackgrass at crop height or above in certain cultivation techniques. In contrast, spring oats, being more competitive, kept blackgrass at bay below crop height.

Economic Realities and Decision Impacts

Examining margins, the average cost of agchem inputs for winter wheat reached £466.66/ha, a 20% increase from the previous year due to higher prices.

Coupled with lower wheat prices, this resulted in negative margins for direct drilling after a cover crop, marking the first negative outcome in the nine years of the trial, with -£405/ha and a substantial seed return of up to 274 ears/sq m.

Spring malting barley in the plough system emerged as the top performer, boasting the highest gross margin of £1,449/ha.

The overall margin differences across treatments amounted to £1,854, underscoring the financial stakes and the importance of making informed decisions.

Looking Ahead and Making Changes

Agrii trials manager Steve Corbett emphasizes that 2023 is a crucial season for farmers to get it right.

Anticipating significant seed returns, he advises farmers to seize this season as an opportunity to elevate their strategies and make necessary changes.

In the face of evolving challenges, maintaining the status quo might not be financially viable.