Effect of mulching on weed infestation and yield of beetroot (Beta vulgaris ssp. rapaceae atrorubra Krass)

Abstract

Weed infestation in a field with beetroots can reduce the yield because the weeds compete with the cultivated plants for nutrition, water and light and depress their growth. The aim of this field experiment was to study the effect of two different organic mulches on weed infestation and yield of beetroot: barley straw mulch (BSM) and mulch from spent mushroom compost (SMCM). They were compared with two control variants: non-mulched but weeded control plot (WC) and non-mulched and non-weeded control plot (NWC). The field experiment was carried out in the experimental field of the University of Forestry, Sofia, for 2 years’ period. The mulching materials were spread manually in a 5-cm thick layer, at the 3-rd leaf growing stage of beetroot. On the 60th day after mulching, the number of weeds on each plot was recorded. It was found out that mulching with BSM and SMCM has a significant weed reducing effect, especially on cockspur (Echinochloa crus-galli L.), red finger-grass (Digitaria sanguinalis (L.) Scop.), common amaranth (Amaranthus retroflexus L) and gallant soldier (Galinsoga parviflora Cav). The yields increased 8–10 times when beetroot was grown with mulches, compared with NWC. In comparison with WC, the beetroot yield was higher by 7.8–9.3 % on the plots mulched with BSM during the 2 years of the experiment; the plots mulched with SMCM showed a yield increase of 22.8 % but only for the first year. Statistical analyses were performed by using the ANOVA. Significant differences between treatments were assessed using Tukey’s test at P = 0.05.