Findings, implications and lessons learned

The study has shown that:

• Application of nitrogen fertiliser had no effect on dry bean yield under the conditions that prevailed in Pietermaritzburg.
• Decreasing the spacing between plants caused an increase in plant height and yield in terms of both total biomass and grain yield, irrespective of the cultivar.
• The determinate dry bean type, Umtata, yielded more grain yield than the indeterminate type, Kranskop, which in contrast produced the higher total biomass.
• It is hypothesised that the poorer grain yield of Kranskop may be due to the late planting date which restricted the period of indeterminate growth.

Regarding statistical methods we have gained a better understanding of:

• the design and analysis of factorial experiments;
• plot design and methods of sampling;
• the use of contrasts in assessing the significance of the linear effect of a factor with more than two equally spaced levels (e.g. the spacing factor);
• the meaning of split-plot in time and approaches to the analysis of repeated measures;
• the value in studying distributions of residuals to be sure that methods of analysis of variance are valid;
• methods of presentation of results from factorial experiments for scientific reports.