Management of alternate bearing and flower induction in litchi cv. China

Abstract

To counteract the alternate bearing in some litchi cultivars, an experiment was conducted on annual guided branch girdling for four consecutive fruit bearing years using a commercial plantation of litchi cv. China litchi at Ranchi, India. Trees were girdled by removing a bark strip (2, 4 and 6 mm width) circularly around the selected 25% and 50% primary branches. During OFF- years, the flowering was increased by 8.62 (2017) and 4.37 (2019) times whereas; it was 3.49 (2015) and 1.68 (2018) times higher during ON-years with the L2G2 treatment (4 mm width girdling of 50% primary branches). Treatment L2G2 also showed the highest cumulative yield with 201.19 kg/tree from four years, while the control showed the lowest cumulative yield with 96.98 kg/tree. After four years, the pooled fruit yield data showed that the highest average yield was recorded in L2G2 treatment (50.30 kg/ tree), and it was lowest in the control (24.24 kg/ tree). The pooled data also showed that the highest average alternate bearing index (I) value (0.73) was observed in the control treatment whereas it was lowest (0.32) in L2G1 (2 mm width girdling of 50% primary branches) followed by L2G2 (0.35) treatment. The LongTerm Yield Index (LTYI) ranged from 31.01% in control to 122.25% in L2G2 treatment. Therefore, 4 mm width girdling of 50% primary branches, reduces alternate bearing behaviour of litchi cv. China. In our experiment, cumulative yield was increased by 2.07 times (under L2G2) as compared to un-girdled trees during the four years of the trial.