The Relationship between Winter Irrigation and Spring Flowering of Guiwei Litchi Trees
The relationship between winter irrigation and branch flowering rates of Guiwei litchi trees was studied for two consecutive winters(2009~2010 and 2010~2011).Trees were sheltered to simulate natural drought processes and treated with different winter irrigation.The rates of flowering branches on the trees under different winter irrigation treatments were investigated in the following spring.The results in the experiment from December,2009 to early January,2010 showed that earlier irrigation and more irrigation times induced more flowers and the flower induction effect was lost if irrigation was applied later than mid-January.Experiments were repeated from December of 2010 to March of 2011 and a similar trend was observed.The loss of irrigation-promoted flower induction after soil water deficiency was observed to occur in mid-February.Our results are contrary to the common notion that drought in winter induces flower on litchi and we propose that adequate and timely irrigation in winter are necessary to help flower induction in litchi trees.