Miscanthus is an emerging dedicated energy crop, which can provide excellent yield on marginal lands. However, this crop is more difficult to harvest than many conventional energy crops such as corn stover and switchgrass due to its tall and rigid stalks. Crop samples for laboratory studies were collected from the field and the effects of roll spacing, roll speed, and crop input of a mechanical conditioning device on the physical conditions of miscanthus were studied in a lab setting. Test results showed that mechanical conditioning is effective to change the physical conditions of miscanthus to make baling possible or easier. Results also showed that the roll spacing had the most significant impact on the physical conditions of miscanthus, shown by a 115% increase in conditioning over a 0.95 cm (75%) reduction in roll spacing. Increased roll spacing and speed were shown to decrease the amount of torque required to condition the miscanthus.
Miscanthus,is a promising bioenergy crop,considered superior to other bioenergy crops because of its higher water and nutrient use efficiency,cold tolerance,and higher production of biomass.Broadleaf weeds and grass weeds,cause major problems in the Miscanthus field.A field experiment was conducted in 2018 and 2019,to assess the effects of pre-emergence(alachlor and napropamide)and post-emergence herbicides(nicosulfuron,dicamba,bentazon,and glufosinate ammonium)on broadleaf and grass weeds in M.sinensis and M.sacchariflorus fields.The weed control efficiency and phytotoxicity of pre-and post-emergence herbicides were evaluated at 30 days after treatment(DAT)and compared to those of the control plots.The results showed wide variations in the susceptibility of the weed species to the treated herbicides.Treatment with nicosulfuron 40 g.a.i.ha^(-1) provided the most effective overall weed control(with 10%visual injury),without affecting the height and biomass of neither Miscanthus species in the field.Post-emergence herbicides such as glufosinate ammonium 400 g.a.i.ha^(-1) and dicamba 482 g.a.i.ha^(-1) were effective and inhibited the growth and density of the majority of weeds to a 100%;however,they showed significant phytotoxicity(toxicity scale of 1-10)to both species of Miscanthus.The application of glufosinate ammonium caused severe injuries to the foliar region(90%visual injury)of both Miscanthus sps.Comparatively,M.sinensis showed a slightly higher tolerance to the herbicides nicosulfuron,bentazon and napropamide with 10%visual injury at the recommended dose than M.sacchariflorus.The present study clearly showed that infestation of broadleaf and grass weeds in Miscanthus fields can cause significant damage to the growth and biomass of Miscanthus and applying pre-emergence and post-emergence herbicides effectively controls the high infestation of these weeds.
Bimal Kumar GhimireChang Yeon YuSeung Hyun KimIll Min Chung