Strategic use of growth regulator overcomes litchi budding problems

Producers need to consider that ethephon applications may be exacerbating problems with erratic flowering, according to Dr Regina Cronjé of Stellenbosch University

-  Glenneis Kriel

Climate change is resulting in winters becoming increasingly milder and the coldest periods only occurring later in winter months in South Africa’s litchi-producing regions, the frost-free parts of Mpumalanga and Limpopo and to a lesser extent KwaZulu-Natal.

As a consequence, the “cold” spell that litchi farmers seek for good flower bud development no longer coincides with the right growth period in the tree.

Dr Regina Cronjé, who recently completed her doctorate on litchis at Stellenbosch University, explained that three-quarters of the litchi plantings in South Africa consisted of the Mauritius cultivar, which needed average temperatures below 20°C for optimal flowering and bud development. With the changing climate, however, shoot growth increased before flowering, resulting in flower formation becoming weaker, which in turn led to poorer fruit formation and, in effect, a smaller harvest.