PLANTLET SIZE AND PLANTING METHOD FOR TISSUE CULTURE BANANA PLANTS
A randomized block trial was established to compare three different tissue culture plantlet sizes (100, 300 (control) and 500 mm tall) with three different planting methods (soil level in bag being the same level as soil level in field (shallow), soil level in bag being 100 mm below soil level in field (control) and plants planted 100 mm below the soil in a 400 mm deep furrow) in terms of susceptibility to blowdown, cycle time, bunch characteristics and yield. The objective was to supply important information on general management practices for tissue culture planting material to growers and nurseries. (For nurseries, knowledge of optimum plant sizes could save production costs. For growers it is essential to know the infield performance of oversized and undersized plants and the optimum planting method for the respective plantlet sizes). Results from the plant crop showed that small plants of 100 mm took 3 weeks (4%) longer to harvest and had 6% lower yields compared with plants of 300 mm size. Plants of 500 mm size showed slightly lower yields compared with 300 mm plants. Regarding planting depth, shallow planting induced smaller bunch mass than the two deeper planted treatments, while plants established in a furrow showed a tendency for longer cycle times. Up to 25% blowdown was measured in the plant crop when plants of 100 mm and 300 mm were planted shallow. Integrating the percentage blowdown into the overall production figures, yield reductions of up to 27% were measured in the plant crop between the 100 mm or 300 mm plant sizes due to shallow planting, and the control. In the R1 cycle the 100 mm plant size outyielded the two bigger sizes by up to 14 t/ha/year. When including the percentage blowdown occurred during the P cycle into yield figures (P + R1 cycle) the 100 mm plant size still outyielded the two bigger sizes with up to 6 t/ha/year. This was mainly caused by shorter cycle time from harvest of the P until harvest of the R1 cycle. As 100 mm plants are difficult to be adequately harden off, more susceptible to transplanting stress and further due to the difficulty in screening for somaclonal variations on 100 mm plants, it may be advisable to use plant sizes greater than 200 mm planted at least 100 mm below soil surface but preferably in a 400 mm deep furrow or basin.
Fraser, C. and Eckstein, K. (1998). PLANTLET SIZE AND PLANTING METHOD FOR TISSUE CULTURE BANANA PLANTS. Acta Hortic. 490, 159-166
Blow down, plant stability, cycle time, bunch weight, mutations