EFFECT OF ENVIRONMENT ON GROWTH AND FLOWERING OF LYCHEE (LITCHI CHINENSIS SONN.)

Moderate day/night temperatures (20°/15° v. 15/10°C) increased vegetative growth and reduced flowering in seven lychee cultivars.
At higher temperatures (25/20° and 30/25°C), vegetative growth was promoted further and flowering eliminated.
All terminal shoots on all cultivars produced panicles at 15/10°C. The relative order for the amount of flowering at 20/15°C was: ‘Wai Chee’> ‘Salathiel’>‘Kwai May Pink’>‘Tai So’>‘Bengal’ >‘Souey Tung’>‘Kwai May Red’. High day temperatures for the shoot (constant 20°C or 30°C day/10°C night or 30°C day/25°C night compared to 15° day/10°C night) and high root temperatures (constant 27.5°C compared to constant 12.5°C or 15°C day/10°C night) promoted vegetative growth and reduced or eliminated flowering in ‘Tai So’ lychee.
A moderate or severe cyclical leaf water stress (irrigation when pre-dawn leaf water potential fell to -1.0 or -2.0 MPa compared to -0.6 MPa) and a constant moderate leaf water stress (-1.0 MPa) reduced vegetative growth in lychee (cv.
Kwai May Pink) grown at 30°C day/25°C night.
Flushing was completely prevented when plants were held at a severe constant leaf water stress (-2.0 MPa). Terminal buds grew out as leafy shoots when water stress was relieved after 7 weeks and the plants maintained at 30°C day/25°C night, but were floral when transferred to 15°C day/10°C night.
These experiments suggest that day shoot temperatures, root temperatures and water stress interact to control the level of flowering in lychee.

International Symposium on the Culture of Subtropical and Tropical Fruits and Crops

C.M. Menzel, D.R. Simpson

https://doi.org/10.17660/ActaHortic.1990.275.16