Valencias are named after the Spanish city of Valencia although its true origin is not known. Valencias are generally very sweet and have a thinner skin than navels and are largely cultivated for juice production.
The South African Valencia harvest is the biggest citrus type to be produced and exported from South Africa and is roughly double the production volumes of navels. Lemons and Limes Lemons and limes are two distinct types of fruit. Lemons are mainly cultivated in temperate climates, while limes are generally produced in tropical and subtropical climates.
These fruits both have an acidic or sour flavour and are used globally for a wide range of applications. Besides their use in the food and beverage sector, lemon and lime extracts are also used in medicines, cosmetics and cleaning products.
The good international demand for lemons has resulted in rapidly growing South African productions in this citrus sector during recent years. Grapefruit Grapefruit are the largest citrus type.
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Change institution. If a sprinkler is used, about 30 mm of water must be applied every 7 days, depending on the weather. Leaf sampling Leaf samples must be taken during the following periods: Easy peelers - end of February Navels and grapefruit - middle of March Midseasons and Valencias - middle of April A leaf sample should represent an orchard smaller than 3 ha in which the soil is homogeneous.
If soil variations occur, separate samples must be taken. Leaves should not be picked from the same side of the tree.
Mature 5 to 7-month-old leaves are picked behind the fruit on the fruiting stem. Important factors when sampling leaves: Different cultivars should be sampled separately. Leaf samples must only be taken from bearing trees. Leaves should preferably be sampled in the morning when the dew has dried off.
Leaves must be free of sunburn, disease symptoms or insect damage. Leaves should be gathered in clean, new paper bags. The bag should be tightly sealed after sampling. If the samples cannot be delivered immediately, the bag should be kept in a refrigerator not a freezer.
Samples must be delivered to the laboratory for analysis within 2 days of sampling. Samples dispatched by post will not be suitable for analysis. Every sample must be accompanied by a completed questionnaire, as this information is important for recommendation purposes. Leaf samples should be taken annually from the same trees mark trees with paint. Mature 5 to 7-month-old leaves behind fruit on fruiting stem are picked for leaf sampling Soil analysis A soil-analysis report of a certain orchard can only be reliable if the soil samples which are analysed are representative of the particular orchard.
Soil should be sampled at the same time as the leaves. It is important that the samples taken represent a homogeneous field or orchard. A soil analysis merely indicates the chemical composition of the soil; physical problems such as waterlogging and plough-soles can only be determined by means of profile holes.
Method of sampling If a soil auger is not available, a spade may be used. Depth Topsoil: 0 to or mm Subsoil: to mm Number of samples A sample must consist of at least 10 subsamples, representing an area of not more than 3 ha. Samples from different orchards should not be combined. Sampling points The samples should be taken evenly by moving diagonally from the corners through the orchard. Samples should be taken under the drip area of the trees in tree basins. Mixing and packing The subsamples taken from a certain orchard should be placed in a clean container not a fertiliser bag and thoroughly mixed.
A sample of about 2 kg is taken from the composite sample and put into a strong, clean plastic bag. Every sample must be clearly marked. In addition to the name of the producer, the number of the orchard, sample number and the depth at which it was taken should be indicated on the label.
Attach the label to the outside of the container. If placed inside the container it might become illegible. Send the sample to the nearest soil analysis laboratory. During the first year, nitrogen may be applied every 2 months. From the second year, nitrogen must be applied twice a year, half in July and half in March. Fertiliser should be spread evenly under the canopy of the tree and irrigated. Very deep irrigations will wash the fertiliser down too deeply and out of reach of the shallow feeder roots.
Phosphorus may be applied at any time of the year. One application should be sufficient. Potassium should also be applied once, early in spring. The table indicates how the fertiliser requirements of growing citrus trees increase. These elements are dissolved in water and applied as a spray onto the tree.
Deficiencies of zinc, copper and manganese often occur and may be applied in 10 l water at the following concentrations: 15 g zinc oxide 20 g copper oxychloride 20 g manganese sulphate. The micronutrient solutions should be sprayed during early spring when the leaves are actively growing. Pruning Citrus trees are not usually pruned, although dead wood must be removed regularly.
To avoid low branches touching the ground, trees are skirted soon after the crop is removed. Branches touching the ground hamper the removal of fruit lying underneath the tree, impede irrigation and promote ant infestation of the trees.
When trees become too big and start growing into one another, pruning is recommended. Pests The use of pesticides in the home garden should be restricted to a minimum. There is a balance between pests and their natural enemies. When pesticides are used injudiciously, this balance is disturbed and a vicious cycle is created.
The result is that these few trees have to be sprayed regularly. Apart from the cost factor, this is dangerous since the amateur fruit producer does not normally use protective equipment such as gloves, overalls or respirators.
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