Pg. 38-40 Vordering met Evaluering van Litchikultivars en Belowende Seleksies (Fase II) in Verskillende Produksiegebiede

Die keuse van lietsjiekultivars in Suid-Afrika vir die lietsjieprodusent, is baie beperk. Dit kan vernietigende implikasies vir die bedryf inhou indien daar byvoorbeeld ‘n siekte uitbreek waarteen kultivars geen weerstand bied nie. HLH Mauritius is die enigste kultivar wat tans in alle lietsjieproduksiegebiede verbou word. Die enigste ander kommersiele kultivar, McLean Red (Madras), is beperk tot die hoerliggende, koeler gebiede van Tzaneen. Die invoer en evaluering van kultivars is dus vir die lietsjiebedryf ‘n hoe prioriteit. ‘n Projek is begin met evaluasieboorde, bestaande uit belowende kultivars wat plaaslik beskikbaar was en kultivars wat hoofsaaklik vanaf Australie ingevoer is, wat gevestig is in al die belangrikste lietsjieproduksiegebiede. Die eerste evaluasieboorde is in 1991/92 gevestig, maar die projek sat uitgebrei word namate nuwe lokaliteite ontwikkel word en nuwe kultivars beskikbaar raak. Daar kan aangeneem word dat kultivars wat in Australie goed doen ook in Suid-Afrika goed sal presteer. Ongeag ‘n soortgelyke klimaat is dit steeds nodig om kultivars onder plaaslike toestande te evalueer as gevolg van die effek van die onmiddellike omgewing op boomprestasie. Die lietsjieprodusent sat dus nie sander ‘n risiko groot hoevee/hede nuwe, onbekende kultivars kan aanplant voordat kultivarevaluasie oor ‘n periode van minstens ses tot agt jaar in ‘n spesifieke gebied gedoen is nie.

Hierdie is ‘n langtermynprojek, aangesien lietsjiebome eers in die vierde tot vyfde jaar na aanplanting begin blom en vrugte produseer. Daarna is nag twee tot drie seisoene nodig om vas te stet of ‘n kultivar goed aangepas is in ‘n spesifieke produksiegebied, al dan nie.

Summary:

• The choice of litchi cultivars in South Africa is very limited, with HLH Mauritius being the only cultivar grown in all production areas, and McLean Red Madras restricted to the high altitude, cool areas of Tzaneen.
• The industry faces risk if diseases strike cultivars without resistance, highlighting the urgency to import and evaluate new cultivars, especially from Australia where climatic conditions are similar.
• An evaluation project started in 1991/92 with blocks of available local and mainly Australian cultivars established across major South African litchi-growing regions.
• Litchi trees take 4-5 years to flower and produce fruit, so cultivar evaluation is a long-term process requiring at least 6-8 years to confirm adaptation to specific areas.
• Cultivar variety extends the marketing season and reduces risk of devastation by diseases and pests, which has severely affected other fruit industries in South Africa.
• Australian cultivars are imported and tested due to their access to Asian litchi diversity and similarity in climate to South African growing areas, but local evaluation is still essential because environmental factors differ.
• The project aims to identify well-adapted early, mid, and late cultivars per region to extend the fresh litchi market period.
• Evaluation also includes promising local selections to complement imported cultivars.
• Differences in soil composition and ground medium in evaluation sites affect tree growth, with some issues like pot-bound root systems in nursery plants noted initially.
• Climate comparisons between key growing areas in Hong Kong, Australia, and South Africa are used to estimate cultivar adaptability, showing similarities but also local environmental influences that make direct performance transfer uncertain.
• Ongoing research into alternative propagation methods is necessary, as multiplication of imported and promising local cultivars is still a major challenge.
• The evaluation trials are sustained by cooperation from private estates and financial support from the South African Litchi Growers Association.
• The long-term goal is to develop improved and regionally adapted litchi cultivars to secure the economic viability and competitiveness of the South African litchi industry.