Open Access

Table 1.

Effects of cropping system components on the blackgrass life-cycle as simulated by ALOMYSYS (Colbach et al., 2006b; 2007; 2010).

Cropping system Intermediate effect Effect on blackgrass
Tillage and mechanical weeding Soil structure Soil compaction increases mortality of germinated seeds
Soil movements = f(soil structure) Seed burial decreases germination and increases pre-emergent mortality due to insufficient seed reserve. Seeds on soil surface germinate badly because of insufficient seed-soil contact Germinated seeds close to soil surface often die because the top soil dries faster.
Exposes imbibed seeds to light if inverting tool, thus breaking dormancy
Triggers germination flush if moist soil
Destroys germinated seeds, seedlings and plants

Crop Choice of cultivation techniques See effects of techniques

Occupies space, uses water and nutrients Decreases components of weed seed production (plant survival, tillers/plant, heads/tiller, flowers/head, seeds/flower)

Seed return to soil seed bank is reduced by crop canopies in multi-annual crops (e.g. grassland, permanent living mulch)

Sowing date Crop emergence date The earlier the weed seedlings emerge relative to the crop, the better they survive and tiller
Date of last tillage The later the last tillage, the more weed seeds have germinated already and are killed by the tillage

Sowing density Crop density Increases weed seedling mortality

Herbicides Weed mortality = f(active ingredient, conditions) Weed mortality decreases with plant density, seed depth (for root-acting herbicides) and weed stage

Decreases tillering on surviving plants

Mowing Destroys tillers and heads. Plants with mature heads die; the remaining tiller again but usually produce less seeds

Nitrogen Increases flowers/head

Conditions during seed production Influence dormancy level and germination rates of newly produced seeds

Harvest Destruction of all plants

Each time plants are destroyed, their seed production, if any, is added to the seed bank.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.

Initial download of the metrics may take a while.