The impact of controlled release fertilizer on the growth and physiology of advanced seedlings of sour passion fruit

Controlled-release fertilizers (CRF) have shown great potential in sustainable agricultural practices, as they provide nutrients according to the metabolic needs of the crop, avoiding leaching and excessive fertilization. Considering that optimizing the propagation material of Passiflora edulis is increasingly crucial for the success of cultivation, particularly due to diseases that affect orchards and limit productivity and expansion, adopting this technology could bring benefits to advanced seedlings that remain in nurseries for extended periods. The objective was to analyze whether the use of CRF influences the quality of advanced sour passion fruit seedlings, considering morphology, physiology, biochemistry, and foliar nutrition during the seedling formation period in the nursery. The experiment was conducted in a 2 × 4 factorial scheme, with two cultivars: ‘FB 200 Yellow Master’ and ‘Redondo Amarelo,’ and four CRF doses: 0, 4, 8, and 12 kg m⁻³ of substrate. The 4–8 kg m⁻³ CRF dose resulted in a significant increase in seedling vigor 85 days after emergence stabilization. Seedling physiology was positively altered by CRF application compared to the control treatment. As CRF doses increased, there was an elevation in stomatal conductance and levels of nitrogen, phosphorus, and copper in leaf tissue. However, the photosynthetic rate decreased with higher CRF doses, resulting in less biomass accumulation in both aboveground and root parts, and in plant growth under the same conditions.