This study evaluated the efficacy of combined chitosan (Chi) and Cymbopogon citratus (DC) Stapf. essential oil (CCEO) to inhibit the fungal phytopathogen Paramyrothecium roridum L. Lombard & Crous and control crater rot in melon (Cucumis melo L.). Effects of several Chi and CCEO concentrations to inhibit the growth of four P. roridum isolates in vitro, as well as the type of interaction of some combined concentrations of Chi and CCEO was evaluated. Effects of coatings with combined concentrations of Chi and CCEO on development of crater rot lesions in melon artificially inoculated with P. roridum during storage (15 days, 25 °C) were measured. Chi (2.5, 3.75, 5, and 6.75 mg/mL) and CCEO (0.3 and 0.6 μL/mL) led to growth inhibition of the four examined P. roridum isolates. Combinations of Chi (5 mg/mL) and CCEO (0.15 and 0.3 μL/mL) had additive interaction to inhibit P. roridum. Coatings with additive combined concentrations of Chi and CCEO decreased the development and severity of carter rot lesions in melon during room storage regardless of the inoculated P. roridum isolate. Therefore, application of coatings formulated with combined concentrations of Chi and CCEO could be alternative strategies to control crater rot caused by P. roridum in melon and decrease synthetic fungicide use in this fruit.

中文翻译：

---

组合的壳聚糖和 Cympobogon citratus (DC ex Nees) Stapf。抑制真菌植物病原体 Paramyrothecium roridum 和控制甜瓜 (Cucumis melo L.) 腐烂的精油

本研究评估了壳聚糖 (Chi) 和 Cymbopogon cittratus (DC) Stapf 组合的功效。精油 (CCEO) 可抑制真菌性植物病原体 Paramyrothecium roridum L. Lombard & Crous 并控制甜瓜 (Cucumis melo L.) 的腐烂。评估了几种 Chi 和 CCEO 浓度在体外抑制四种罗里杜姆分离株生长的效果，以及某些 Chi 和 CCEO 组合浓度的相互作用类型。测量了混合浓度的 Chi 和 CCEO 的涂层对人工接种 P. roridum 的甜瓜在储存期间（15 天，25 °C）发生坑腐病的影响。Chi（2.5、3.75、5 和 6.75 mg/mL）和 CCEO（0.3 和 0.6 μL/mL）导致四种检测的 P. roridum 分离株的生长抑制。Chi (5 mg/mL) 和 CCEO (0.15 和 0. 3 μL/mL) 具有添加剂相互作用以抑制 P. roridum。无论接种的 P. roridum 分离株如何，在室内储存期间，添加混合浓度的 Chi 和 CCEO 的涂层都降低了甜瓜卡特腐病病变的发展和严重程度。因此，应用混合浓度的 Chi 和 CCEO 配制的涂料可能是控制甜瓜中 P. roridum 引起的坑腐病和减少该水果中合成杀菌剂使用的替代策略。