Cereal and Legume Intercropping as a Means of Reducing Weed Competition in Cereal Crops

Crynodeb

This research investigates the potential of cereal-legume intercropping, specifically combining spring wheat and two varieties of spring peas (semi-leaved and full-leaved), as a biological method for controlling weed competition in cereal crops grown in the U.K., without herbicides or mechanical weeding. Conducted over two growing seasons (2016 and 2017), the trials assessed the effectiveness of intercropping compared to monoculture wheat plots in suppressing weed growth. Intercropping initially proved effective in reducing weed infestation by forming a dense crop canopy that limited sunlight available to weeds. However, severe weather in 2016 resulted in crop lodging at the wheat dough stage (Zadoks 75-85), damaging the pea canopy and subsequently increasing weed growth due to enhanced light penetration. Delayed harvest conditions further contributed to increased weed biomass. Monoculture wheat plots consistently demonstrated lower weed biomass, attributed to stable plant density and minimal canopy disturbance. In 2017, favourable weather conditions helped maintain intercrop canopy stability until pea senescence, after which weed growth accelerated due to increased light availability and accumulated nitrogen from the legumes. Findings from both seasons indicated that although intercropping initially suppressed weeds effectively, adverse weather conditions and late harvesting significantly raised weed biomass compared to monoculture plots. Lodging emerged as a key factor influencing weed growth, along with nitrogen released from decomposing legumes, benefiting weed species with high nitrogen demands. Overall, the study supports intercropping as a practical biological approach to weed control under optimal harvesting conditions. However, cultivar selection and timely harvesting are critical to preventing lodging and subsequent weed proliferation. Further research addressing these factors is recommended to enhance intercrop efficiency and stability in temperate climates.

Dyddiad Dyfarnu	2025
Iaith wreiddiol	Saesneg
Sefydliad Dyfarnu	Prifysgol Aberystwyth
Goruchwyliwr	Daniel Thorogood (Goruchwylydd)