design, fabrication and pseudo field evaluation of a sugar beet crust breaker and weeding unit equipped with an infrared sensor

in conventional cultivation of sugar beet the weeding and crust breaking are mostly performed manually. the objectives of this research were to design, fabricate and evaluate a soil crust breaker and weeding implement equipped with a detecting sensor. each unit consisted of a distance detecting sensor and a hydro-motor for driving the blades and pneumatic valves for moving the blades. the hydro-motor was activated by the sensors. to avoid damaging the plants, a command signal was sent to the pneumatic valves to move the blades up and down and pass safely. three configurations of cutting blades were considered which could be mounted to the crust breaker. the field evaluation was conducted with two tractor forward speeds (0.4 and 1 km h-1) and four plant-to-plant spacings within rows (20, 25, 30 and 40 cm) all with three different blade shapes. for field evaluation split plot experiments arranged in a completely randomized block design with three replications. the number of plants damaged (evaluated only for four-lobe blades) and size of broken crusts (evaluated for all blade shapes) for various treatments were recorded and compared. the results of analysis indicated that the higher the inter-row spacing the lower the injury to the plant. the highest and the least damage to the plants occurred for within-row plant spacings of 20 and 40 cm, respectively. the forward speed was also significantly affected the percent of plant damaged. the forward speed of 1 km h-1 at 20 cm spacing had the most (59%) and the speed of 0.40 km h-1 at 40 cm spacing had the least effect (3.3%) on the percent of plant damage. the two-lobe blade could result in the maximum surface area broken.