Growing Food: A Guide to Food Production

Trace Element Deficiencies: see also Section 1Cd, page 23:

• Boron: lumpy fruit, leaves with water-soaked spots. Copper: die-back with gum
  pockets or blisters on young growing branches, leaves and fruit. Then leaves and
  fruit drop off, and twigs become distorted. Treat with sprays of 5 kg copper sulphate
  in 10 kg lime per hectare. Iron: chlorosis of leaves, veins remain green.
  : Epsom salts
  (magnesium sulphate). Zinc: known as “Mottle Leaf”, it is fairly common. Leaves
  become mottled and reduced in size. Control: spray 2.25 kg zinc sulphate and 1.13
  kg slaked lime in 455 litres of water – 4.5 litres per tree. Molybdenum: “Yellow
  Spot”, controlled by adjusting the soil pH if possible to pH 5.5–6.5.

YIELD
Highly variable, according to species, variety, soil, climate, etc.

UTILISATION

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manufacture.

LIMITATIONS

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• 3–6 years before any fruit is produced.

Guava

Psidium guajava

Amrood, Jamphal (Hindi); Zaituna (Amharic, Ethiopia); Banjiro (Japanese)

The guava tree is indigenous to tropical America where it still grows wild. It is now
found throughout the tropics and subtropics. It spreads easily, often by birds
distributing the seeds, and can become a weed in some places such as Fiji and
Queensland. The name “Guava” comes from the Spanish guayaba, from a South
American Indian word.

Magnesium: very common. Chlorosis of whole leaf. Control

Average yields, in kg/ha/year, are, approximately: limes 25–80, oranges 150 –1800,
and grapefruit 150–1000.

Goyave (French); Guayaba (Spanish); Goiaba {fruit}, Goiabeira {tree} (Portuguese);

256 TONY WINCH

Citrus plants are mainly grown for the juicy fruits. They contain almost 90%

water, and variable amounts of sucrose, glucose and fructose.

The skins are a source of pectin, used in jam making and for the ascorbic

acid/Vitamin C (90-150 mg per 100 g edible portion).

Lemons and sour oranges provide citral and limonene, used in perfume

Citrus plants need to be carefully and skilfully grafted, and also pruned in the

early stages.

Intolerant of poorly drained or saline soils, and low temperatures.

Susceptible to attack by many pests and diseases.

Trace element deficiencies are common, and these are not always easy to

accurately diagnose and/or treat.