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CITRUS FRUITS | CITRUS TYPES
In South Africa Suitable areas for citrus are grouped together in four climatic zones, which are :
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Climatic Zone
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Cold Areas
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Cool, Inland
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Intermediate Area
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Hot Area Low & High Humidity
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The East Cape Midlands, Gamtoos River Valley, Sundays River Valley, Amanzi, Southern Natal, South Western Cape and Citrusdal, Knysna and the surrounding areas.
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Rustenburg, Lydenburg / Burgersfort, Ohrigstad and Potgietersrus and surrounding areas.
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T Marble Hall, Groblerdal, Nelspruit, Hazyview, Barberton, Letaba (Tzaneen) and Levubu.
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Low humidity- Tshipise, Limpopo Valley, Letsitele, Lower Letaba and Hoedspruit.
High Humidity-Malelane,Komatipoort, Swaziland Lowveld, Pongola and Nkwalini
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Climatic Suitability of cultivars
Citrus South Africa are divided into cultivar groups because of their origin, characteristics and ripening times. Each cultivar group has a unique climatic requirement that is dependent on temperature, heat units, day length and light and humidity. These List of Citrus groups are as follows:
Cold Areas
Cool Inland Areas
Intermediate Areas
Hot Areas
Physical and Chemical Soil Requirements
Soil can loosely be grouped as sandy soil, sand loan, clay loan and clay soils.Ideal Chemical Soil Requirements are:15% - 25% clay percentage (above 30% is marginal)The pH (H20) should be between 6,5 and 7,5No salts in the top 50cm.
Ideal Physical Soil Requirements are:
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Soil depth of at least 50cm to 1m.
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Well drained soils, especially in the first 50cm.
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No peds larger than 100mm in diameter.
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No stratified alluvium in top 50 cm.
Soil preparation is essential to optimize citrus production. The primary purpose of soil preparation is to get the root zone as homogenous as possible to optimize root development and growth. This will also alleviate soil density problems. Chemical imbalances of the soils can be corrected during soil preparation.It is important to know that proper soil samples were taken and tested at a reputable institution. Soil preparations should be done to subsequently optimize tree and root growth.
POPULAR CITRUS CULTIVARS AND ROOTSTOCKS
Cultivars
Each cultivar group has a range of different cultivars that matures from early to late and/or has unique characteristics, such as red pigmentation. There are approximately 210 commercial varieties being planted in South Africa. Listed are the most common/promising varieties per cultivar group.
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Mandarin-Satsumas – Miho wase, Kuno, Owar
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Clementines – Marisol, Nules, Clementine Late
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Mandarin Hybrids – Ortanique, Minneola Tangelo, Thoro Temple, Nova, Nouvelle, Fairchild, Empress
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Lemons-Eureka, Eureka Seedless, Lisbon
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Limes-Tahiti, Bearss
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Grapefruit-White – Marsh-Pink – Redblush-Red – Star Ruby
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Navels-Early Maturing – Fukumotto, Newhall, Navelina-Mid Maturing – Palmer, Bahianinha, Cara Cara-Late Maturing – Glen Ora Late, Witkrans, Lane Late,
Australian selections
Midseasons
Valencia
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Early Maturing – Benny, Limpopo SL
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Mid Maturing – Alpha, Midknight, Delta
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Late Maturing – Delicia, Ruby Valencia, Old clone selections
Pummelo Types
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Pomelit, Shaddock, Oroblanco, Jackson, Melogold
Kumquat
Rootstocks
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All citrus produced in South Africa today are budded on rootstocks, and the majority of these are certified trees. Reasons being:
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Rootstocks influence tree and fruit characteristics, such as, production, fruit size and fruit colour.
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Rootstocks are used to regulate tree height.
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Rootstocks have various degrees of resistance to soil born diseases and viruses.
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Rootstocks are used to overcome some shortages with regards to physical and chemical compositions of soils such as high pH soils.
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Rootstocks improve tree age.
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Rootstocks can improve some physiological problems associated with some cultivars, such as creasing.
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Rootstocks vary in terms of cold and drought resistance.
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Some rootstocks can even sustain flood situations.
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