Leaf production, apex expansion, and yield of cauliflower (Brassica oleracea var. botrytis) in the lowland tropics

Two field experiments were carried out at Lombok in Indonesia to determine whether tropical cauliflower (Brassica oleracea var. botrytis) cv. Milky was able to produce curd in the high, non-inducing temperatures of the lowland tropics. Leaf number and apex diameter were measured during the experiments. Leaf production was linear with time but the apex expansion rate changed abruptly at the end of the juvenile phase. The abrupt changes occurred at 50+/-0.7 and 45+/-1.5 days after transplanting (DAT) in Experiments 1 and 2, respectively. Curds were initiated at around 55 DAT, with the apex size at initiation being 0.525 mm. The curds continued to grow but their quality was poor. The poor curd quality was attributed to high temperature and irradiance during the curd growth phase.