Study design

Study 1

The skeleton ANOVA table is as shown.

The trial at Umbumbulu was run under the conditions in which the farmers were already engaged. Sowing was done by hand on ploughed and harrowed fields. A hand-hoe was used to make each hole, organic fertiliser was mixed with the soil and one corm was planted in the hole. Weeds were controlled by hand hoeing once a month. Farmers were involved throughout the study from soil preparation to harvesting.

The trial at Ukulinga was run as for Umbumbulu with the exception that field workers at Ukulinga from the UKZN Experimental Research Farm assisted with the field work, e.g sowing, hand hoeing and harvesting.

Corm sizes vary both among and within landraces. The corms used for this study were in the following size ranges: 21 – 60g for Dumbe-Dumbe, 11 – 40g for Mgingqeni and 5 – 20g for Pitshi. The corms for Mgingqeni and Pitshi were harvested at Ukulinga in 2007 and those for Dumbe–Dumbe were obtained from farmers in Umbumbulu.

The numbers of plants that emerged per plot were counted and emergence percentages calculated at monthly intervals until no other plants emerged.