Pg. 6-7 Beheer van Boomgrootte van Lietsjiebome

In hierdie artikel word gerapporteer oor die voorlopige resultate van ‘n projek waar boomgrootte van lietsjiebome beheer is deur middel van snoei en die gebruik van chemiese groeireguleerders, sonder dat opbrengs en vruggehalte negatief beinvloed word. In hierdie stadium, vier seisoene na aanvang van die projek, kan die gevolgtrekking gemaak word dat boomvolume effektief beheer kan word en dat groei konstant gehou en beperk kan word met ‘n snoei-behandeling of die chemiese groeireguleerder paklobutrazool, asook ‘n kombinasie van beide. Die behandelings het egter tot in hierdie stadium meer variasie getoon in opbrengs as die kontrole borne. Alhoewel die behandelings meer arbeidsintensief is en hoer insetkostes vereis, is geen negatiewe invloed waargeneem op vruggehalte tussen enige van die behandelings nie. Dit is dus nog nie moontlik om in hierdie stadium finale gevolgtrekkings te maak nie, aangesien die langterym effek van die behandelings nog bepaal moet word. Die projek word voortgesit en daar word onder andere beplan om te kyk na residu’s van paklobutrazool in vrugte.

Summary:

• The study explores controlling the size of mature litchi trees through pruning and chemical growth regulators, specifically paclobutrazol (PP 333), without negatively affecting yield and fruit quality.
• Tree volume and growth can be effectively controlled and limited through pruning, paclobutrazol application, or a combination of both, although these methods involve higher labor and input costs.
• Treatments started four seasons ago showed more variation in yield compared to control trees, but no negative effects on fruit quality have been observed so far.
• Paclobutrazol foliar sprays increased yield but did not control tree volume.
• The project involved treatments such as low and high concentration sprays on young flower clusters and post-harvest shoot growth, ground applications, selective pruning of fruit-bearing branches, and combinations thereof.
• Tree volume measurements indicate that ground applications of paclobutrazol and pruning effectively reduced tree size over three seasons, while other spray treatments had no significant volume control effect.
• Yield varied significantly between treatments and seasons, with abnormal climatic conditions possibly influencing variation; some treatments achieved better cumulative yields than control trees.
• Fruit quality, including fruit size and ripening, showed no significant differences between treatments over four seasons; some paclobutrazol ground treatments delayed ripening and affected color but produced slightly larger fruit.
• The long-term effects and paclobutrazol residue levels in fruit remain to be determined, so final conclusions are pending further study.
• Overall, managing litchi tree size through pruning and growth regulators appears feasible and effective, but requires continued research for safety and efficacy.