An evaluation of the performance of mechanical weeding mechanisms for use in high speed inter-row weeding of arable crops

An assessment was made of the ability of different mechanical weeding mechanisms to control weeds at different growth stages in the uncropped area between crop rows and at different forward speeds. Performance of the mechanisms was assessed in a replicated field experiment. A uniform population of rape was established to represent weed growth. This supplemented the naturally germinated weeds. Both the number of rape and natural weeds surviving after treatment were counted to show the level of control achieved. Highly significant differences between treatments were found. Some mechanical treatments, under the conditions examined, achieved equal or better control than the herbicide treatment. Of the weeding mechanisms studied the harrow comb was the least effective; the ducksfoot achieved high levels of control but caused unacceptable soil movement. The powered rotary hoe worked well at all growth stages at 5 km/h but its performance declined as working speed was increased. The brush weeder did not do as well as some mechanisms because its inability to penetrate and the low speed of the rotor. The ground driven rotary weeder worked well at all speeds but was less able to cope with established plant growth. Overall, the most promising mechanism for high speed weeding of a wide range of arable crops was the sweep. (C) 1997 Silsoe Research Institute.