Pg. 72-86 Timely stimulation of budbreak to improve litchi flowering

Flower initiation in the litchi cultivar ‘HLH Mauritius’ takes place during the drop in temperature in the beginning of winter. Trials were undertaken with different rest breaking agents in an attempt to stimulate growth when conditions were favourable for flower initiation. In Nelspruit branch treatments were made with KN0₃ (1%, 2% and 3%), LB urea (0.5% and 1.0%), Dormex® (0.5%, 1.0% and 2.0%), CPPU (5, 10, 20 and 40 mg/L), Kelpak® (0.4%), Promalin® (0.02%) and ProGibb® (5 mg/L) on their own or in combination. Treatment dates were 7 April, 21 April and 5 May 2003. Although none of the treatments improved all aspects investigated (flowering, fruit set, retention and fruit size), the 3% KNOY 0.5% LB urea and 0.4% Kelpak® treatments on 5 May showed the best results. Additionally, applications were made on trees in the Malelane area with 200 ml/tree Kelpak® and Ultra Hume® (mid March), 3% KN03 and 40 mg/L CPPU (beginning May), as well as tip pruning and tip pruning in combination with 3% KN03 (first and third week of April). Late flush was treated with 0. 05% Ethapon®. The 3% KN03 and 200 ml/tree Kelpak® gave the best results, while the tip pruning treatments gave negative results regarding flowering and production. All treatments except the 200 ml/tree Kelpak® significantly improved fruit size. These positive results are encouraging and it is important that research with rest breaking agents should continue.