References on Mango

Swart S. H., Swart G., Labuschagne C.

Author Affiliation: QMS Agric Science, PO Box 416, Letsitele, 0885, South Africa.
  : 511-519

Abstract : Stem-end rot, soft brown rot and anthracnose are the most important postharvest diseases of mango fruit in South Africa. Management of mango diseases is mainly based on orchard sanitation, pre-harvest fungicide applications and postharvest hot water and prochloraz treatments. In general, anthracnose is well controlled by these management strategies. Controlling stem-end rot and soft brown rot is, however, problematic. During the 2004/2005 growing season, the replacement of some fungicides, with specifically timed other fungicides, in semi-commercial, pre-harvest spray programmes, were evaluated to determine the effect of strategically timed fungicide applications, early and late, in standard programmes. Additionally, the effect of these pre-harvest programmes in combination with postharvest treatments with fludioxonil and prochloraz was also evaluated to determine the effect of the different chemicals, strategically placed in pre-harvest spray programmes and applied as postharvest dip treatments, on postharvest decay of mangoes in semi-commercial trials. Different results were obtained at different trial sites due to several variables such as cultivar, disease pressure, climate and spray efficacy. Fungicide programmes, applied during the 7-month period from flowering to harvest, had specific effects regarding the causal pathogens and severity of postharvest diseases. The timing of a specific fungicide application influenced the efficacy of a programme, but other factors such as coverage and disease pressure played an equally important role. The addition of oil to azoxystrobin improved coverage of especially the fruit, and therefore, disease control. Other additives to improve disease control on mangoes should be investigated. The efficacy of azoxystrobin was also improved by increasing spray volume. Results at Jonkmanspruit showed that higher spray volumes, compared to Bavaria and Ryfontein, improved efficacy of disease control. The importance of good pre-harvest spray programmes to ensure effective control of postharvest diseases was confirmed in this trial. The value of using certain fungicides during the late blossom and early fruit set period in order to decrease stem-end rot was also confirmed in this study. At Bavaria estates, the advantage of using carbendazim/flusilazole (Punch C) and azoxystrobin (Ortiva) in some programmes was demonstrated. At Jonkmanspruit, propiconazole (Tilt) and Ortiva reduced the occurrence of stem-end rot. Anthracnose was only controlled effectively when spray volume and frequency of application was sufficient to ensure continuous protection against infection. Postharvest dip treatments clearly reduced decay of mangoes obtained from all 3 sites. When pre-harvest programmes were effective and disease pressure was reduced in the orchard, postharvest decay was controlled more effectively. Results clearly showed that low postharvest decay was associated with effective protection of fruits throughout the growing season, irrespective of the postharvest control strategy. Fludioxonil showed superior control of stem-end rot and effectively reduced anthracnose, while prochloraz controlled anthracnose very effectively and showed some control of stem-end rot during these trials.