Weed control and crop protection

Once hemp is established, it requires minimal attention. With its rapid growth rate of about 4 cm per day, the field becomes filled with plants and very dense within approximately two weeks, effectively preventing weed development. Hence, hemp has shown no susceptibility to detectable diseases, eliminating the need for plant protection products before or during cultivation. Following sowing, the crop is left undisturbed until harvest. It can serve as a resting area for various birds, including skylarks, as well as small mammals (van den Oever et al., 2023).

The sowing rate and row spacing play a vital role in hemp cultivation. For fibre production, a high sowing rate and narrow row spacing are commonly used, resulting in dense crop growth and early row closure, which supports weed suppression. In contrast, seed production requires lower seed rates and wider row spacing to optimize seed yields. However, this can lead to weed issues due to slower or incomplete crop coverage.

When it comes to diseases and pests in hemp cultivation, another ecological advantage with economic significance of hemp cultivation becomes clear. In addition to the absence of herbicides - with proper cultivation - no plant protection agents against fungal, bacterial or viral pathogens are necessary in hemp cultivation. One reason for the resistance of the hemp plant to diseases is breeding. All hemp varieties are very heterogeneous populations. This means that a hemp population consists of many individuals with different genetic material, which results in different resistance to different diseases. As a result, there is a low risk that, in the event of a disease outbreak, the entire crop will be infected if plant protection measures are not initiated and will react with severe yield losses.