Lantana camara mulch as a highly effective weed control treatment and motivation for vegetation management

Plant material-based mulches are an environmentally friendly and valuable tool for weed management that also enhance the soil moisture and nutrient status in agricultural and urban landscapes. Towards identifying a beneficial use for the highly invasive lantana (Lantana camara L.) the present study compared the weed suppression of mulches made from lantana and Eucalyptus spp. (eucy hereafter) plant material. Lantana stem + leaves mulch (lantana mulch hereafter) was more suppressive of annual ryegrass emergence and growth than eucy mulch. In trial-I, lantana mulch at the highest application rate of 100 t ha⁻¹, reduced annual ryegrass emergence and biomass by 94 and 99 % compared to 46 and 75 % by eucy mulch, respectively. Lantana mulch was also more suppressive of tillage radish, reducing its biomass by 58 % at the highest application rate of 100 t ha⁻¹. The ED₅₀ value for annual ryegrass biomass was 24 t ha⁻¹ for lantana, whereas eucy required more than twice the amount of mulch to achieve similar reductions. The ED₅₀ values for tillage radish biomass by lantana mulch was 26 t ha⁻¹ while the eucy mulch rates used failed to achieve a 50 % reduction in biomass. In trial-II, lantana leaf mulch inhibited the emergence and biomass of annual ryegrass by 100 % at the application rate of 40 t ha⁻¹. The ED₅₀ values of leaf mulch for emergence and biomass were 13 and 9 t ha⁻¹ for annual ryegrass and 24 and 12 t ha⁻¹ for tillage radish, respectively. This study has established the superior efficacy of lantana-based mulches in suppressing grass and broadleaf weeds compared to conventionally used eucy mulch. The value of lantana mulch as a highly effective weed management tool will potentially contribute towards the management of this invasive weed by creating an incentive for the utilisation of lantana biomass.