Cauliflower quality and yield under tropical conditions are influenced by boron fertilization

The aim of this study was to evaluate the influence of boron fertilization on the quality and yield of cauliflower growing under tropical conditions. The study was carried out in randomized block design in split plot design. The main plots four boron doses (0, 2, 4, 6 kg ha-¹) whereas subplots with 3 cauliflower genotypes (Verona CMS, Sarah and Sharon) with three replicates. Among the genotypes, the higher fresh curd weight means were observed to Sharon followed by Verona and Sarah with 1.007, 0.801 and 0.583kg plant-¹ respectively. In relation to boron doses, genotypes of Sharon, Verona and Sarah showed responsive to boron doses with maximum fresh curd mass of 1.378, 1.216 and 0.804 kg plant-¹ with doses of 6, 4.18 and 4.06 kg B ha-¹. Total yield showed variation up to 307.96% positive with boron added. In contrast, there was observed a high loss ratio in the harvest mainly due to “hollow stem” incidence. Correlations were observed between the incidence of hollow stem, cultivars and boron doses. Analyzing hollow stem disorder between genotypes, Sharon presented higher incidence than Sarah and Verona CMS with values of 88.1%; 73.10% and 66.7%, respectively. Sharon and Verona CMS presented low incidence on the doses of 2 and 4 kg B ha-1 (57.1 and 42.9%) respectively. For Sarah genotype boron dose was not significant whereas 85.7% of the curds were checked with hollow stem disorder. Overall, in this study we can conclude that: (i) Sharon genotype presented the higher productivity, whereas demand more boron fertilization than the other genotypes evaluated; (ii) Under tropical conditions Verona CMS is more tolerant to high temperature than Sarah and Sharon exhibiting more marketable products on postharvest by reducing hollow stem and physiological disorders.   Key words: Brassica oleracea, quality, mineral nutrition, tropical horticulture.