Characterization of generative development in early maturing litchi 'Early Big', a novel cultivar in Taiwan

Abstract

Introduction. A short harvest window is common in litchi production worldwide, leading to imbalance between supply and demand for fresh fruit. This problem can be mitigated with early-maturing cultivars, such as ?Early Big?, released in 2010 in Taiwan. Our goal was to characterize the generative development in this novel litchi cultivar. Materials and methods. The patterns of female flowering and fruit development, and fruit abscission were investigated in ?Early Big? litchi in 2013 and 2014. The relationship between the second round (2 nd R) blooming and the first round (1 st R) fruit was studied. The ambient temperature in both years was recorded. Results and discussion. 2?3 weeks after full female bloom (AFFB) the 2 nd R flowering occurred, followed by fruit abscission with loss of 95% fruit within 4 weeks AFFB in ?Early Big? litchi, resulting in low yield at harvest. The 2 nd R blooming was negatively correlated with the 1 st R fruit retention rate from week 4 AFFB in 2013. Overall, the period of low temperature from November through to the following March was longer in 2013/2014 than in 2012/2013. The trait of early maturing in ?Early Big? is mainly due to early flowering. Temperature may be related to the generative development in ?Early Big?. The accumulation of low temperature in early spring may be related to poor initial fruit set. Conclusion. The presence of 2 nd R flowering also potentially reduced the 1 st R fruit set and retention. These issues must be addressed to develop field strategies to improve yield in ?Early Big? litchi.