Apricot trees grow well in temperate zones, but they thrive in areas with cold, dry winters and dry, hot summers. Low-lying areas and those prone to heavy frost should be avoided.
Most cultivars are prone to fruit crack under high humidity conditions and heavy rainfall during flowering will promote blossom blight. Apricots are used as fresh produce, for drying, canning and juicing, as well as for jam and preserve making.
CHOOSE THE RIGHT CULTIVAR
The so-called Cape Apricot was the most important variety cultivated in South Africa before 1900, and is probably a descendant of the original Chinese apricots. Old Cape, Early Cape and Late Cape (or Sweetstone) came into use as farmers started to plant grafted trees.
Newer cultivars such as Royal (for drying) and Bulida (for canning) were introduced in the early 1900s and late 1930s respectively. These two cultivars dominate the industry, accounting for more than 50% of the area under production in South Africa.
Charisma, which was released in 2005, heralded a new era for apricots because of its attractive, red-blushed skin. The European market is moving away from traditional yellow apricots and looking for apricots with more blush – almost like nectarines. Charisma has 50% blush, but some new international cultivars have even more.
The number of cold units in an area will determine the suitability of a specific cultivar in a specific region. If there are too few cold units, some cultivars are prone to delayed foliation.
Unfavourable production conditions can also lead to bi-annual cropping, where trees bear normal yields one year and sub-normal crops the next. This can be prevented by not planting in areas prone to bi-annual cropping and by sound management practices, such as an efficient fertilisation and pruning programme.
SOIL AND FERTILISER REQUIREMENTS
- Apricots prefer fertile, well-drained, well-prepared soils with a potential root depth of at least 600 mm.
- Sandy, acidic soils should be avoided and those that show signs of periodic or permanent wetness should be drained.
- It is important to seek expert advice on the specific soil-rootstock-cultivar combinations.
- The soil type determines the rootstock that should be used.
- Different stone fruit rootstocks are used in different countries for apricot production, but Royal seedling is still widely used in South Africa because it is compatible with most apricot cultivars and soil types.
- Base the fertilisation programme on soil and leaf analysis results.
- Factors such as the removal of the soil’s nutrients by the crop, effective application of fertilisers and fertilising according to the expected production, should also be taken into account.
- Take soil samples before preparing the soil, and then every three years after planting.
- Leaf samples should be taken annually during January to establish the plant’s nutrient requirements.
- Fertiliser is expensive and some of the nutrients (nitrogen for example) leach readily from soils.
- Seek expert advice to ensure fertiliser is applied correctly and at the correct dosages.
- A general guide to the application of nitrogen fertilisers is given in the table below.
- Apply phosphorous during soil preparation.
PRUNING AND OTHER MAINTENANCE
A well-formulated plan, based on knowledge of the underlying principles of pruning, is essential. Someone who prunes the tree during its first 3 years must have a very clear picture of what the tree will look like when it reaches maturity.
There are several reasons for pruning:
- To shape the young tree.
- To remove dead and diseased branches.
- To carry out early thinning of flower buds.
- To remove branches which prevent sunlight from reaching the inner parts of the tree.
- To simplify fruit harvesting.
Prune trees from mid-July until the end of August, when they are dormant. They can also be pruned in summer to remove water (wild) shoots and improve the penetration of sunlight into the trees.
Only prune on sunny days to prevent fungal infections in the pruning wounds. Shears should be disinfected often while pruning, to prevent the spreading of disease between trees. A
diluted bleach-solution can be used.
The fungus Eutypa lata can cause apricot tree die-back.
Symptoms are seen in summer:
Leaves on a branch suddenly turning yellow, wilting and dying after fruit has been harvested. To control this fungus, prune on dry, sunny days, not soon after rain, and in early winter. Cover larger pruning wounds with an effective fungicide.
IRRIGATION AND HARVESTING
The soil type; quality, availability and accessibility of water; climatic conditions; the age and size of trees; as well as the type of irrigation system used will determine how much, and how often, to irrigate.
- Sandy soils require a little water at short intervals.
- Soils containing more clay need more water, applied at long intervals.
- Post-harvest irrigation is important, as the next season’s fruit buds are formed during the post-harvest period.
- Although the trees are dormant in winter, they still need water.
- Trees in the summer rainfall areas should be irrigated at least once a month during winter.
- Ripe fruit is soft, sensitive to handling and susceptible to decay-causing organisms.
- Fruit can be stored for 4 weeks at low temperatures and relatively high humidity, depending on the maturity when picked.
NUTRITIONAL VALUE OF FRUIT
- Fruit plays an important role in the human diet as it is a source of fibre, carbohydrates, minerals and vitamins A, C and E.
- Fruit such as peaches and apricots contain vitamin A, and citrus , nectarines, strawberries and kiwi are rich in vitamin C.
- Avocados are an excellent source of vitamin E.
- Fruit also contains important nutrients such as potassium, calcium, phosphorous, magnesium, manganese, iron and zinc.
- Important anti-oxidants, such as carotene and anthocyanins, are also contained in fruit.
- This article was written by Odette Beukes and Chris Smith and first appeared in Farming SA.