DEVELOPMENT AND PERFORMANCE EVALUATION OF A ROW CROP WEEDER

Abstract

Weed control is important in crop production to prevent losses in yield and to reduce production costs. The adoption of mechanical weeders rises over time as the preferred option due to environmental concerns and the detrimental effects of chemicals on soils and crops. Therefore, a two row disc weeder was developed and the performance was evaluated while the effects of various machine and operational parameters on the performance of the weeder were established. The evaluation of the machine was carried out at the teaching and research farm of the Federal University of Technology, Akure, Nigeria. Two hundred stands of eight weeks cassava TME 419 with average height of 40 cm spaced at 90cm along and within rows were used for the evaluation. The evaluation was performed at three tractor speeds (2.5 km/hr, 5.0 km/hr and 7.5 km/hr). The depths of cut were 20, 30, 40, 50 and 60 mm with tilt angle of the disc at 25 0 , 30 0 , 35 0 , 40 0 and 45 0 . All observations were carried out using three replications while the average of the outcome was estimated and recorded. From the data, the proposion of the weed cleared (%), weed retained (%) and crop damaged (%) were evaluated and recorded. The result of the analysis revealed that the highest weeding efficiency and the lowest uncleared weeds were obtained at 250 tilt angle, 20 mm cutting depth and 2.5 km/h tractor speed. The developed model shows that the combination of the tilt angle, cutting depth and tractor speed accounted for 91.61%, 88.41% and 91.61% variation in the weeding efficiency, percentage of the damaged crop and the percentage of uncleared weeds respectively at (P < 0.05) significance level. It also revealed that a unit increase in the tilt angle would decrease the weeding efficiency of the inter-row mechanical disc weeder by 0.51%, would increases the percentage of crop damaged by the inter-row mechanical disc weeder by 0.03% and increase the percentage of uncleared weed during evaluation of the inter-row mechanical disc weeder by 0.71%. So also, a unit reduction in the cutting depth would increases the weeding efficiency of the inter-row mechanical disc weeder by 0.07%, increase the percentage of crop damaged by the inter-row mechanical disc weeder by 0.01% and decreases the percentage of uncleared weed during evaluation of the inter-row mechanical disc weeder by 0.07%. Therefore the weeder is recommended to be operated at 250 tilt angle, 20 mm cutting depth and 2.5 km/h tractor speed to obtain highest weeding efficiency, lowest uncleared weeds and minimal crop damage. The weeder can be adopted for small and medium scale farmers.