MOST DANGEROUS FUNGAL DISEASE OF MANGO : STEM END ROT
About Stem End Rot Disease of Mango
Stem End Rot is a disease caused by the soil-borne fungus. The name of this fungus is Lasiodiplodia theobromae. First at the primary stage, the disease targets the stem end or pedicel region of the fruit. This disease condition is favoured by high temperatures and rainfall. In the primary stage, the Epicarp becomes dark around the base of the pedicel. By the course of time, the affected area enlarges to form a circular black patch. In humid weather conditions, it turns the whole fruit completely black within three days. The pulp of the affected fruits becomes brown and soft.
Disease Stem End Rot
Symptoms of Stem End Rot in Mango
- Infected fruits look like dark brown to black discoloration at the stem end. This discoloration spreads toward the upper portion of the fruit.
- The affected area appears sunken. Sometimes surrounded by a water-soaked margin.
- Under humid weather conditions, these affected areas rapidly expand and within three days and in severe stage, the entire fruit turns completely black.
- The pulp becomes brown and softer.
What causes Stem End Rot?
The fungi Dothiorella dominicana, Phomopsis spp., Botryodiplodia theobromae and Lasiodiplodia theobromae cause Stem End Rot in mango.
Basket of Mangos Affected by Stem End Rot
Characterization of Stem-End Rot in the Sense of Botany
Stem End Rot is the second most serious disease in the world after anthracnose. In arid regions, on the other hand, it becomes the major post-harvest pathogen.
Pathogens enter stems through natural openings and wounds, especially during flowering. These fungal pathogens primarily live endoparasitically in the xylem as well as the phloem, and are asymptomatically present in the stem tissue until fruit maturity. Immature fruits are resistant to stem rot. This resilience is compromised when the fruit begins to ripen during fruit storage. During maturation, the fruit undergoes dramatic biochemical and physiological changes. These include changes in ethylene release and other plant hormones in climacteric fruit, accumulation of soluble sugars, loosening of cell walls, decreased phytoanticipin and phytoalexin levels, decreased inducible plant defense mechanisms, and environmental changes. It is included. host pH
Factors and Treatments Affecting STEM END ROT
1. Cultural control
· Regular weeding.
· Mulching the trees.
· Sanitation means removing debris.
· Destroying the affected plant.
2. Harvesting with Stem
One of the most effective ways to reduce Stem End Rot using by a simple harvest practice, i.e., harvesting fruit with short stems (pedicel) using sharp instruments like secateurs. The common practice of detaching the fruit, which leaves no stem. Surprisingly, this minor change in harvesting practice gets a positive impact on reducing Stem End Rot incidence in mango.
3. Chemical Treatments
Using Fungicides are the most traditional and effective strategy for controlling postharvest diseases. A variety of pre- and postharvest fungicidal treatments were suggested to reduce or delay the Stem End Rot disease of Mango.
Spreading stage of Stem End Rot Disease
4. Postharvest Chemical Control
Postharvest fungicidal treatments are more common for controlling Stem End Rot and can be applied by spraying, or in waxes or coatings. Prochloraz, a nonsystemic imidazole, is a well-recognized fungicide that is used commercially for controlling postharvest diseases in mango fruit.
5. Postharvest Biological Control
· Predatory Mites eat Fungus spores like Neoseiulus californicus
· Using Beneficial Fungus
· Use beneficial Bacteria like Pseudomonas fluorescens
6. Physical Control
UV-C was found to control various fungal pathogens, including STEM END ROT-causing pathogens, by pruning and exposure of fruit to sunlight could be a good method for reducing postharvest STEM END ROT.
- Hot Water Treatment
Hot-water immersion also reduced Stem End Rot of papaya and mango.
8. Combined Treatments
In mango, a combination of hot water brushing (HWB) along with prochloraz followed significantly reduced incidence of Stem End Rot from 86 to 10%
