Weeds as Bioindicators of Ecological Conditions in Organic Carrot and Onion Crop

Summary The obtained results indicate the possibility of weed control in organic intercropping production systems of carrots and onions with the application of corn gluten, together with the ecological assessment of habitat based on bioindicator values of weed species. A total of 29 weed taxons are present in the intercoped and pure crops of carrots and onions, grown without (CO) and with the application of corn gluten (CO-G). Although floristically uniformed, 24 taxons (CO) and 23 taxons (CO-G), the total weediness on the CO-G variants was 24% higher. The highest value of fresh weed biomass was recorded on the treatment of pure onion crop with gluten application (2844.85 g/m2), while the lowest value was recorded on the treatment of intercropped carrot and onion (1004.99 g/m2). Ecological assessment of habitat, based on indicator values and abundance of weed species, indicates favorable climatic conditions with favorable temperature (Tx̄ - 4) and light (Lx̄ - 4) regime, which refers to temperate continental climate conditions (Kx̄ - 2,7). Soil indicators indicate slightly drier conditions (Fx̄ – 2,6), slightly acidic to neutral pH (Rx̄ – 3,3), rich in nutrients (Nx̄ – 4), with moderate humus content (Hx̄ – 3), moderate aeration (Dx̄ – 2,8) and locally salted (s) with the participation of salinity indicators in the amount of 54% (CO) and 40% (CO-G). The presence of heavy metals tolerance (m) indicators in the amount of 46% (CO-G) and 41% (CO) should not be neglected, which imposes the need for additional analysis of soil for heavy metal content. Based on the analysis of obtained indicator values, it can be concluded that these ecological conditions correspond to the development of carrots and onions and that the lowest values of fresh weed biomass were recorded on the treatment of intercropping of carrots and onions, without application of corn gluten.