When working the soil, care should be taken to avoid any damage to the banana
plants shallow root system.
GROWTH CONDITIONS
Day length: no known response.
Growth period: for the plant crop, 9–18 months from planting to harvesting,
depending on variety, growth conditions, etc. From the shooting of the inflorescence
to harvest, 2.5–4 months. The period between plant crops varies from 4–6 years
(commercial fields) to 10 years (central America) to 50–100 years (traditional
farming). In theory, banana fields can be in permanent production due to the
continuous production of suckers, but in practice are rarely kept for more than 60
years. Sometimes the plants are replanted every two years.
Ripening of the fruit is often done artificially after the fruit has reached the country
of destination by exposure to ethylene gas.
°C is optimum. Growth is reduced below 21°C. Frost sensitive.
mm/month are applied. Optimum annual rainfall is about 2000–2500 mm, but some
varieties are grown with much less or much more water than this.
Wind: can be a major cause of crop loss, by tearing the leaves and, more
importantly, by breaking and uprooting plants. Windbreaks are therefore often
necessary.
Bananas are very susceptible to hormonal weedkillers, though Dalapon and some
others can be used.
Mineral deficiencies: symptoms are commonly seen when insufficient fertiliser is
used (see Section 1Cd, page 23):
- Calcium (Ca)—leaf margins become yellow, then brown—similar to Potassium
deficiency; - Potassium (K)—leaf margins become yellow, then general leaf necrosis
(unprogrammed death of cells or tissue); small bunches with thin fingers. Can be
shown up by nematode attack; - Zinc (Zn)—bunchy tops;
- Phosphorus (P)—slow growth, then leaf margins become scorched and the base
of the corm roots; leaves are short; few hands and fingers per bunch; - Nitrogen (N)—slow, stunted growth; leaves become yellowish;
- Iron (Fe)—young leaves chlorotic between the veins. If severe, general chlorosis.
- Magnesium (Mg)—young leaves chlorotic between the veins; leaf margins wavy.
If severe, leaves become dark brown and hang down, and leaf sheaths split.
Altitude: sea level up to about 1800 m is optimum. They can grow up to about
Pruning: a controversial subject, but in general pruning to 3–6 stems produces
earlier, larger bunches and plants with better resistance to Borer (Weevil) attack.
2400 m but development is then normally slow and weak due to low temperatures.
250 TONY WINCH
Temperature: 27–29
Rainfall: to grow well, needs a minimum of 25 mm/week. When irrigated, 150–200
Weeds: important to remove all perennial weeds, and also to provide a mulch.