Effect of Different Fertilization Regimes on the Weed Community in Swiss Chard

Abstract

SUMMARYWeed community of Swiss chard was studied in plots with different fertilization regimes. Fertilization doses correspond to 50% (F50), 100% (F100) and 150% (F150) nutrient demand of Swiss chard. Sinousia consists of 29 species, out of 26 genera and 17 families, among which dominant are: Sorghum halepense, Solanum nigrum, Kickxia spuria, and Atriplex patula. The analysis of the biological spectrum indicates the dominance of therophytes with 75.8%, while hemicryptophytes contribute the spectrum with 17.2%. Considering the effect of fertilizers on the crop growth and weediness, general conclusion is that fertilizers benefit both the crop and weeds, but increased doses of fertilizers had better effect on the crop yield than on weediness. The average crop yield was highest in the regime F150, as well as total weediness F150. However, analysing the species abundance, cover per single plot and crop yield in each regime of fertilization, some deviations are noticed. Such as, in the plots No 10 (belongs to F100) and No 17 (belongs to F150) the total weed cover was 10%. In eight plots which belongs to F50 the weed cover exceeded this value.