By using a confounded design, the reduction in number of plots per complete block to one-third per incomplete block was not as efficient as it should be regarding treatment precision. Unless soil fertility gradient is multidirectional to be accounted for by reducing block size, incomplete block orientation may seem to be a limiting factor. Due to field requirementfor designing surface irrigation, watering pathways and inter-tier borders are present. The occurrence of many of these natural barriers between plots within a block present a likely negative impact on block homogeneity if they run perpendicular to the direction of each block since they affect adjacent plots within the same incomplete block. In addition, relative to the sod growth pattern as the case in forage crops, the growth nature of the canola crop, as individual branching plants, may influence plot to plot variation regarding final plant count if missing hills is experienced. Therefore, in future experiments, confounded designs need to be applied to cover crops, in which incomplete blocks be laid out parallel to natural barriers or fit spatial analyses models to account for more complicated soil variations.
Both canola plant density per unit area and cultivar are critical factors in maximizing seed yield. These two factors effects on canola seed yield seem to be affecting the ability of plant to produce more pods with higher seed weight. Although results showed that achieving high seed yield was obtained by plant density of 9.5 plants m-2 compared to 7.1 and 11.9 plants m-2, it is necessary to study a wide range of plant density in relation to canola yield. On the other hand, since harvest time did not play a significance role for maximizing canola yield in this trial, this may differ if there are more varied planting dates. |
