Abstrakt

Modelling the Performance of a Tractor-Mounted Cocoyam Harvester

RO Akinbamowo

A cocoyam (Xanthosoma spp.) harvester was designed and fabricated at the Federal University of Technology, Akure using locally available materials. Field tests were conducted to evaluate the effect of different levels of operational parameters on the performance of the implement. The operational parameters were forward speed (v), rake angle (α) and web speed (n). The harvester was operated at the forward speeds of 2, 4 and 6 km/h, rake angles of 15°, 20° and 25° and web speeds of 540, 1000 rpm. These combinations were tested on a factorial basis employing a split - split plot design with three replications. The performance of the implement investigated was the successfully harvested tubers and tuber damage analysed using ANOVA at P < 0.05. Cocoyam cormels were harvested from 10m long rows of crops on clay loam with a spacing of 0.8m x 0.6m according to each treatment. From the results, a mean harvest rate of 12.02 tonnes/h and mean digging efficiency of 84.2% were obtained. The results implies that, while the harvester can be operated for higher field capacity at 6 km/h. 20° blade angle with the cleaning web powered at 1000 rpm, the optimum condition of digging up most cocoyam cormels with minimum dug losses is at 4 km/h, 20° blade angle and 540 rpm web speed. The field tests also revealed that machine performance was limited by delays due to clogging and machine adjustments. Analysis of variance performed on the descriptive statistics for machine performance variables obtained showed that the results are significant for one of the response variables. Machine performance variables are significant at P < 0.05 for harvest rate.