Verbetering der cassave-cultuur door middel van proefvelden

Cassava was shown not to require deep tillage. The influence of planting time was very great. The optimum time could be easily established by experiments. Closer spacing diminished root production per plant but this loss was compensated by the larger number of plants. Only very wide spacing notably diminished yield. Planting deeper than 2 in. diminished meal yields. Cuttings from gardens 17.5 months old proved better than from gardens 19.5 and 24.5 months old. The removal of stems from the plantations for the making of cuttings gave a meal loss of 8 to 9 % if one stem was left on each plant and one of 10 to 16 Y. if all stems were cut. Cutting 5 months before harvesting caused slightly less setback than 9 months before it. The influence of fertilization was rarely marked (K, P) or almost negligible (N, Ca). Green manuring had no influence. An optimum age period for ripeness could be established. Seven varieties could be ranged according to their productivity, as also 7 seedlings selected by Koch.