Response of ‘Prata anã’ banana to post-harvest phosphite application

Abstract The objective of the present study was to determine the best phosphite source and concentration to control anthracnose and its effects on the physical and chemical characteristics of ‘Prata-anã’ banana. Bouquets of banana fruits were immersed in solutions containing different formulations of copper phosphite FCu1 (4% Cu + 20% P2O5), FCu2 (4% Cu + 22% P2O5) at concentrations of 0.5; 1.0, 1.5- and 2.0-mL L-1 and potassium phosphite FK (42% P2O5 + 27.7% K2O) at concentrations of 0.5; 1.0, 1.5 and 2.0 mg L-1. Controls consisted of the application of pure water and Imazalil application (0.5 mL. L-1). Subsequently, anthracnose incidence and severity were evaluated every three days. The physical and chemical characteristics of fruits were evaluated at the end of the anthracnose intensity evaluation. The experimental design used was completely randomized. The results showed that the different phosphite sources FCu1, FCu2 and FK at the concentrations tested were not effective in controlling anthracnose. The physical and chemical characteristics of fruits were influenced by the different phosphite sources and concentrations applied. Fresh fruit mass loss is proportional to the applied phosphite concentration.摘要 本研究旨在筛选可有效防控炭疽病（anthracnose）的最优亚磷酸酯（phosphite）来源与施用浓度，并探究其对普拉塔阿纳（Prata-anã）香蕉物理与化学品质特性的影响。将香蕉果穗分别浸于含不同配方的亚磷酸铜（copper phosphite）FCu1（含4%铜+20%五氧化二磷）、FCu2（含4%铜+22%五氧化二磷）的溶液中，浓度梯度设置为0.5、1.0、1.5及2.0 mL·L⁻¹；同时采用亚磷酸钾（potassium phosphite）FK（含42%五氧化二磷+27.7%氧化钾）溶液，浓度梯度为0.5、1.0、1.5及2.0 mg·L⁻¹。对照组分别设置清水喷施组与抑霉唑（Imazalil）喷施组，抑霉唑施用浓度为0.5 mL·L⁻¹。随后每3天对香蕉的炭疽病发病率与病情严重度进行一次评估。在炭疽病病情评估结束后，测定香蕉果实的物理与化学品质特性。本实验采用完全随机试验设计。结果表明，供试浓度下的FCu1、FCu2与FK三种亚磷酸酯制剂均无法有效防控炭疽病。不同亚磷酸酯来源与施用浓度均会对香蕉果实的物理与化学品质特性产生显著影响。果实鲜质量损失率与亚磷酸酯施用浓度呈正相关。