Fig. 1

Schematic diagram and flower bud percentage of ‘Feizixiao’ litchi under different temperatures. a Schematic diagram of working principle and structural element of the mini temperature control box. The mini temperature control box includes thermostat water bath with function of refrigeration cycle①, plastic tube②, thermal insulation material③, transparency glass plate④, thermal containers⑤, radiators⑥ and electronic thermometer with the probe⑦. The collected images were authentic and original from the truest experiment, by using a drawing tool Coreldraw x4. b Percentage of flower buds in ‘Feizixiao’ litchi at different time points at 15 °C and 25 °C