Great willowherb

Great willowherb (Epilobium hirsutum) is a perennial herbaceous plant belonging to the Onagraceae family. Known for its adaptability, this weed thrives in moist environments, including riparian zones, ditches, marshes, and poorly drained agricultural fields. It is recognized as a persistent species due to its vigorous growth and ability to colonize damp patches of arable land.

In farming, the great willowherb is particularly troublesome in areas with high soil moisture. It interferes with the growth of various crops, including cereals and vegetables, by dominating the space and depriving crops of essential light, water, and nutrients. Its rapid spread can lead to significant economic losses if not managed during the early stages of infestation.

The biology of Epilobium hirsutum is characterized by a strong, creeping rhizome system that allows for extensive vegetative expansion. The stems can grow up to 150 cm in height and are covered with fine hairs. The plant produces numerous wind-dispersed seeds throughout the summer, facilitating its spread across large areas and making it difficult to eradicate once established.

The weed's harmfulness lies in its competitive nature and the physical obstruction it causes to agricultural machinery during harvesting. Because it often grows in dense, thick clusters, it can cause machinery blockages and slow down field operations significantly. Controlling it requires a persistent strategy due to its resilience against simple mechanical cultivation.

Control measures should be integrated. Agrotechnical approaches include improving soil drainage to make the environment less favorable for the weed, along with deep tillage to disrupt the rhizome network. Chemically, the application of systemic herbicides (such as glyphosate-based products) on fallow land or during the active growth phase is highly effective at killing the plant down to the roots.

• Improvement of field drainage and water management
• Deep plowing to exhaust rhizomes
• Application of systemic herbicides
• Preventive measures to avoid seed dispersal