Effect of pre-treatments with natural compounds for controlling anthracnose in papaya variety Red Lady

Purpose: Papaya (Carica papaya L.) is an economically important fruit crop affected by anthracnose caused by Colletotrichum gloeosporioides. The study was carried out to test two essential oils; Citronella oil and Cinnamon oil and two leaf extracts; Lantana camara and Ocimum tenuiflorum on four occasions of fruit development as pre-treatment assay in the field condition. Research Method: Essential oils were prepared as an emulsifier and leaf saps were extracted from dried leaves and both were set to 10% concentration. The experiment was conducted in a two-factor factorial experiment with Randomized Complete Block Design. Five treatments including the control were applied for four blocks representing stages of fruit development. Disease severity (0–5 scale) and disease severity index were calculated and statistically analyzed using ANOVA, MINITAB and Tukey’s pairwise analysis. Findings: According to the obtained results, four occasions of application of the selected treatment were highly significant with a minimum level of DSI (34.67 ± 4.62). L. camera leaf extract was highly effective as a pre-treatment with the least values for disease severity percentages (5.78 ± 0.43), disease severity score (0.3 ± 0.17) and disease severity index (26.67 ± 6.36). Research limitations: Flower bud initiation was delayed than the date expected due to the unpredicted heavy rainy condition. Originality/Value: The most effective block treatment interaction was shown on three occasions of application of L. camera leaf extract. This study facilitated the development of the most promising pre-harvest management strategy to control anthracnose disease which causes by the fungal pathogen C. gloeosporioides.