2025/12/31 by Kondwani Kamsikiri, Davie M. Kadyampakeni · 1 voice
Agricultural and Biological Sciences · #Banana Cultivation and Research #Phytoplasmas and Hemiptera pathogens #Plant Pathogenic Bacteria Studies
paper · doi:10.21273/hortsci19009-25
openalex created_date 2025/12/31 · openalex publication_date 2025/12/31 · openalex updated_date 2026/06/26
Huanglongbing (HLB) continues to be a major constraint in the Florida citrus industry. HLB-affected citrus trees experience micronutrient deficiency due to impaired nutrient allocation. Recent studies have demonstrated that infected trees require higher doses of micronutrients than typically recommended for citrus production to achieve optimum nutrition. However, application rates of some micronutrients, such as molybdenum (Mo), for young and mature HLB-affected citrus trees remain unclear. Therefore, this study was conducted at the Citrus Research and Education Center to evaluate the effect of varying Mo rates on growth and biomass accumulation of 2-year-old HLB-affected and HLB-free ‘Valencia’ sweet orange ( Citrus sinensis L. Osbeck) trees under greenhouse conditions. The trees were divided into two groups: half were inoculated with the HLB causal pathogen and the remainder were used as Candidatus Liberibacter asiaticus ( C Las)-free (non-HLB) controls. In each group, four Mo rates were evaluated: 0.00 kg·ha −1 (control), 1.12 kg·ha −1 (1× grower standard rate), 2.24 kg·ha −1 (2×), and 4.48 kg·ha −1 (4×). Results showed that Mo application significantly enhanced below-ground growth in both C Las-inoculated and healthy trees, whereas aboveground effects were not significantly affected. Small and medium roots of HLB-affected trees responded more positively to Mo application than those of non C Las-inoculated trees. Application rates above 1.12 kg·ha −1 suggested potential toxicity, indicating that Mo fertilization should be applied cautiously and guided by tissue analysis. Findings support maintaining the current standard rate of 1.12 kg·ha −1 Mo, which may benefit both HLB-affected and healthy trees.