Mastering Mango Gummosis Quiz

Explore key aspects of mango gummosis, its symptoms, management, and differences from similar diseases to enhance your horticultural knowledge.

1. Symptoms Identification

   Which of the following is a primary symptom indicating gummosis in mango trees?

   1. Sticky gum exuding from the bark
   2. Leaf tip browning
   3. Yellow bands on fruit skin
   4. Powdery mildew on leaves

   Explanation: Sticky gum exuding from the bark is characteristic of gummosis in mango trees. Powdery mildew on leaves is a symptom of powdery mildew disease, not gummosis. Yellow bands on fruit skin are more associated with viral infections, and leaf tip browning typically results from nutrient deficiencies or salt damage.

2. Causal Organism

   Which pathogen is most commonly responsible for causing gummosis in mango plants?

   1. Lasiodiplodia theobromae
   2. Erysiphe cichoracearum
   3. Phytophthora infestans
   4. Colletotrichum gloeosporioides

   Explanation: Lasiodiplodia theobromae is the primary fungus causing mango gummosis. Phytophthora infestans causes late blight in potatoes, Colletotrichum gloeosporioides is known for anthracnose, and Erysiphe cichoracearum causes powdery mildew in cucurbits.

3. Disease Spread

   How does gummosis most often spread among mango trees in orchards?

   1. Through pruning wounds and injuries
   2. By insect vectors feeding on leaves
   3. Through infected seeds during planting
   4. Via airborne spores over long distances

   Explanation: Gummosis typically spreads via wounds, such as those caused by pruning or mechanical injuries, allowing the pathogen to enter. Airborne spore dispersal is more common for foliar fungi, insect vectors are more relevant to viral diseases, and seed transmission is rare for gummosis.

4. Management Practice

   Which management practice is most effective in reducing gummosis incidence in mango orchards?

   1. Irrigating trees daily regardless of weather
   2. Applying protective fungicides to wounded areas
   3. Planting mango trees in densely packed rows
   4. Over-fertilizing with nitrogen-rich fertilizers

   Explanation: Applying fungicides to wounds helps prevent pathogen entry and reduces disease incidence. Over-irrigation and dense planting can increase humidity and disease risk, while excess fertilizers often stress trees rather than prevent gummosis.

5. Disease Confusion

   Mango gummosis may be confused with which other disease because both can involve gum exudation?

   1. Bacterial canker
   2. Black spot
   3. Sooty mold
   4. Powdery mildew

   Explanation: Bacterial canker can also cause gum exudation from stems and branches, making it similar to gummosis. Black spot mainly causes fruit skin lesions, powdery mildew produces a white powdery coating on leaves, and sooty mold appears as black fungal growth on leaves and fruit.