In terms of performance, the prototype developed in this study achieved mean field capacity, field efficiency and planting depth of 0.151 ha/h, 87% and 4.34cm, respectively. In comparison, corresponding figures for were 0.12 ha/h,71% and 4.94 cm, respectively. The planting depth achieved is within the acceptable range recommended for optimum germination of maize and there commended range for soil depth over seed in relation to seed size . Since a uniform planting depth is necessary for better crop stands , the planting unith as the potential to help small-scale farmers to achieve better crop production.The mean effective field capacity of the planting unit was found to be 0.151 ha/hindicating that it takes a farmer slightly over six hours to plant a hectare of land which is more effective than planting with hoes and other ox-drawn planters.One of the common problems associated with traditional methods of seed sowing is the high seed rate.
Results obtained indicate that the average seed rate achieved by the developed planting unit ranged between 30 kg/ha and 42 kg/ha with an average of35 kg/ha. The relatively higher seed rate may be attributed to the fact that the unit discharges 2 3 seed per seed cell. Available literature indicates that seeding rates for manually operated maize planters may vary considerably. For example, reported a seed rate of 43.2 kg/ha during their experiments on a manually operated maize seeding attachment for an animal drawn cultivator while reported a seed rate of 35 kg/ha from a study on modification and development of a two-row maize planter. These two studies show that the planter seed rate is within the range of what other researchers have achieved with two rows maize planters.reported that seeding maize at below optimum rates increases risk of not attaining maximum yield potential for a given environment while seeding maize at populations above the optimal,grow lights increases risk of encountering stress atcritical growth stages and suffering yield reductions.Analysis of seed damage by the planter indicated that the percentage of damaged seed ranged between 3% and 5% with an average of 4%, which is relatively high but comparable to results by other researchers including and .
Analysis of differences in seed damage by the two seed metering devices using one-way ANOVA showed statically significant differences with the right hand seed metering device damaging more seed than that on the left hand side . The relatively high seed damage may be attributed to flaws in the fabrication of the metering devices; for example,attributed high percentage of damaged seeds to inadequate clearance in the seed metering device. According to , seed damage increased with increasing metering device speed and this was attributed to shearing and jumping of seeds against the wall of the hopper at high speeds and the magnitude of damage depended on the strength of the seeds. However, the effect of speed on seed damage was not investigated in this study.In relation to seed spacing, the planter achieved an average seed spacing of 31cm, which is slightly higher than the design seed spacing of the planting unit which was set 30 cm as recommended for maize by agronomists. Additional tests done in relation to seed spacing were the average seed missing index ,multiple index and quality of feed index.
The results for those tests were as follows: 3% average seed missing index, 0% seed multiple index, 4% quality of feeding index which indicates that the planter has 97% precision in terms of seed spacing. This result is similar to , who found average field seed planting space by flute metering unit for maize as 34 cm compared to the theoretical value of 32 cm. This result could be due to the seeds metering device housing and seed tube which are the major source of inaccuracy in seed spacing. The cultivating unit was tested in the field at an average operating speed of 3.5km/h. Results indicated that the cultivator mean working width was 43 cm, the mean weeding depth was 3.5 cm while the cultivator mean weeding efficiency was 79.1%. These results are comparable to those obtained by other researchers who did similar work but in different environments and contexts such as .