Bananas and Food Security - Bioversity International

388 Les productions bananières / Bananas and food security – Session 2
Table 2. Effect of peak force level on postharvest potentials of Musa fruit.
Peak force level NBF (%) Days to ripe Weight loss (%)
0 0 11 10
1-49 25 9 20
50-100 31 8 27
SD 3 0.7 2.8
CV (%) 16 7.8 15
LSD (Pwww = 0.5) = Col 5.1 1.2 4.8
NBF: Number of fingers broken.
Table 3. The resistance of different Musa genotypes to mechanical stress*.
Genotype No of hands No of hands No of fingers No of fingers
per bunch broken per bunch broken
Agbagba 7 3 30 11
Cardaba 5 2 67 5
TMPx 548-9 9 8 136 30
* Average of six bunches for each genotype at peak force level 70 joules.
been identified as major causes of premature deterioration in fruit because they initiate
physiological and pathogenic stress (Karikari et al. 1980). Stress results in production of
ethylene and increases rate of respiration and weight loss. Losses in Musa fruit may be
reduced if bunches are dropped from heights less than 4 to 6 meters.
The differences in weight loss and ripening period of bunches of Musa fruit stored at
the top, middle and bottom of a stack of bunches is shown in Table 4. Although the
observed differences were not significant, a trend of increased stress was exhibited as
static pressure increased. Bunches at the bottom had more stress, expressed in higher
weight loss value and shorter ripening period. The implication of this is that the
expected green life of a Musa bunch may be reduced when bunches are under static
pressure. Using horizontal dividers inside distribution vehicles could reduce static
pressure. The use of horizontal dividers will reduce the number of bunches in a stack. In
the export of dessert bananas, fingers are stored in boxes to prevent static loading and
boxes are only stacked to a specific height to avoid damage to the boxes. Unfortunately
containers are not used for plantain distribution in Nigeria. Nevertheless static pressure
could be reduced by reducing the period of stress. Reduction of the stress period could
be achieved by shortening the delivery period to 4-6 hours. Practically, this is not feasible
in the present Nigerian situation because of bad roads, but may work well in future.
Conclusion
The positive attributes of plantain hybrids with respect to storage include a long
ripening period, a slow rate of respiration and slow rate of ripening. The hybrid plantain
therefore, is expected to exhibit higher usability index compared with cooking banana