Mango Tree Fungal Diseases

• Mango trees, like all living organisms, are susceptible to a variety of diseases that can affect their health, productivity, and fruit quality. These diseases can be caused by fungi, bacteria, viruses, and other pathogens.

Fungal Diseases

• Anthracnose is a common fungal disease affecting mangoes, caused by Colletotrichum gloeosporioides.
  • It manifests as dark, sunken lesions on leaves, twigs, flowers, and fruits.
  • Severe infections can lead to defoliation, blossom blight, and fruit rot.
  • High humidity and warm temperatures favor the development and spread of anthracnose.
  • Management strategies include pruning infected branches, improving air circulation, and applying appropriate fungicides.
• Powdery mildew is another fungal disease that affects mangoes, caused by Oidium mangiferae.
  • It appears as a white, powdery coating on leaves, flowers, and young fruits.
  • Severe infections can cause premature leaf drop, flower abortion, and reduced fruit set.
  • Cool, dry weather with high humidity favors the development of powdery mildew.
  • Management strategies include pruning infected branches, improving air circulation, and applying appropriate fungicides.
• Alternaria leaf spot is a fungal disease caused by Alternaria alternata.
  • Leaf spots begin as small brown lesions that enlarge and develop concentric rings.
  • Severe infections can cause defoliation, especially in young trees.
  • Humid weather conditions favor the development and spread of Alternaria leaf spot.
  • Management strategies include pruning infected branches, improving air circulation, and applying appropriate fungicides.
• Stem-end rot is a post-harvest fungal disease that affects mango fruits, caused by Lasiodiplodia theobromae and other fungi.
  • It causes a brown or black rot at the stem end of the fruit, which gradually spreads to the entire fruit.
  • Warm, humid storage conditions favor the development of stem-end rot.
  • Management strategies include harvesting fruits at the proper maturity stage, avoiding injuries during harvesting and handling, and applying appropriate post-harvest fungicides.
• Verticillium wilt is a soilborne fungal disease caused by Verticillium dahliae.
  • Symptoms include wilting, yellowing, and premature leaf drop, followed by branch dieback and eventual death of the tree.
  • The fungus infects the roots and disrupts the water and nutrient transport within the tree.
  • Verticillium wilt can be difficult to control, but management strategies include planting resistant varieties, avoiding soil contamination, and improving soil drainage.

Bacterial Diseases

• Bacterial black spot is a bacterial disease affecting mangoes, caused by Xanthomonas citri pv. mangiferaeindicae.
  • It manifests as small, angular, black lesions on leaves, twigs, and fruits.
  • Severe infections can cause defoliation, twig dieback, and fruit blemishes.
  • Warm, humid weather conditions favor the development and spread of bacterial black spot.
  • Management strategies include pruning infected branches, applying copper-based bactericides, and using disease-free planting material.

Viral Diseases

• Mango malformation is a viral disease that affects mangoes, caused by a complex of Fusarium mangiferae and possibly other pathogens.
  • It causes vegetative and floral malformations, including shortened internodes, clustered leaves, and hypertrophied flower parts.
  • Severe infections can reduce fruit production and tree vigor.
  • The exact cause and transmission of mango malformation are not fully understood.
  • Management strategies include pruning infected branches, applying growth regulators, and using disease-free planting material.
• Mango mosaic virus is a viral disease that causes mosaic patterns on leaves, reduced fruit size and quality, and stunted tree growth.
  • The virus is transmitted by grafting and possibly by insect vectors.
  • There is no cure for mango mosaic virus, so management strategies focus on prevention, including using virus-free planting material and controlling insect vectors.

Other Diseases and Disorders

• Sooty mold is a dark, sooty coating on leaves and fruits caused by various fungi that grow on honeydew secreted by insects such as aphids, scales, and mealybugs.
  • Sooty mold can reduce photosynthesis and fruit quality.
  • Management strategies include controlling the insect pests that produce honeydew.
• Fruit cracking is a physiological disorder that affects mango fruits, characterized by cracks on the fruit surface.
  • It can be caused by various factors, including fluctuations in soil moisture, temperature extremes, and nutrient imbalances.
  • Fruit cracking can reduce fruit quality and marketability.
  • Management strategies include maintaining consistent soil moisture, providing adequate nutrition, and protecting fruits from sunburn.
• Soft nose is a physiological disorder that affects mango fruits, characterized by a soft, spongy area at the apex of the fruit.
  • It is caused by calcium deficiency and high nitrogen levels in the fruit.
  • Soft nose can reduce fruit quality and marketability.
  • Management strategies include applying calcium fertilizers, balancing nitrogen levels, and avoiding over-irrigation.

Disease Management Strategies

• Integrated disease management (IDM) is a holistic approach to disease control that combines various strategies to minimize disease incidence and severity while minimizing the use of chemical pesticides.
  • Cultural practices include selecting disease-resistant varieties, using disease-free planting material, pruning infected branches, improving air circulation, and maintaining proper sanitation.
  • Biological control involves the use of beneficial organisms such as fungi, bacteria, and viruses to suppress disease-causing pathogens.
  • Chemical control involves the use of fungicides and bactericides to control fungal and bacterial diseases.
  • Regular monitoring and scouting for diseases are essential for early detection and timely intervention.