Garlic Roots Under Attack! Quiz

Explore the key diseases affecting garlic roots in horticulture. This quiz covers pathogens, symptoms, and best management practices to keep garlic plants healthy.

1. Identifying Fusarium Basal Rot

   A garlic farmer notices yellowing leaves and a brown discoloration starting from the base of the bulb; which disease caused by a common soil fungus is most likely responsible?

   1. White rot
   2. Fusarium basal rot
   3. Nematode infestation
   4. Downy mildew

   Explanation: Fusarium basal rot causes yellowing leaves and brown or pink discoloration at the bulb base, typical symptoms described here. White rot mainly shows as fluffy white mycelium with black sclerotia. Nematode infestation generally causes stunted growth and distorted bulbs. Downy mildew primarily affects the foliage rather than the roots or bulb base.

2. Garlic White Rot Symptoms

   Which symptom is most indicative of white rot disease in garlic fields?

   1. Swollen, distorted roots with galls
   2. Purple streaks on leaves
   3. Grey powdery coating on leaves
   4. Presence of white fungal growth and black sclerotia on roots

   Explanation: White rot is characterized by white fungal growth and small black sclerotia on the roots and bulb. Purple streaks on leaves are not typical of white rot. Swollen and distorted roots are signs of nematode damage, not fungal diseases. A grey powdery coating is generally linked to powdery mildew.

3. Nematode Impact on Garlic Roots

   If a garlic crop exhibits stunted growth, twisted roots, and a sponge-like bulb texture, which pathogen is most likely involved?

   1. Alternaria porri
   2. Botrytis allii
   3. Stem and bulb nematode
   4. Fusarium oxysporum

   Explanation: Stem and bulb nematode causes stunted plants, twisted roots, and spongy bulbs. Fusarium oxysporum causes basal rot but not sponge-like texture. Botrytis allii typically causes neck rot rather than affecting roots directly. Alternaria porri is mostly related to leaf blight, not root or bulb symptoms.

4. Best Practice for Preventing Garlic Root Diseases

   Which of the following is a widely recommended cultural practice to reduce the risk of soilborne garlic root diseases?

   1. Planting garlic in the same spot every year
   2. Using only chemical fungicides
   3. Over-irrigating garlic fields
   4. Crop rotation with non-allium species

   Explanation: Rotating with non-allium crops lowers pathogen pressure in the soil and helps break the disease cycle. Planting garlic repeatedly in the same area increases risk. Over-irrigation can promote root diseases. Relying solely on chemical fungicides is less sustainable and often ineffective without cultural practices.

5. Recognizing Garlic Pink Root

   A grower sees pink to purple coloration on garlic roots, leading to shriveled and poorly developed bulbs. What is the most probable cause?

   1. Blue mold
   2. Pink root caused by Phoma terrestris
   3. Smut disease
   4. Penicillium rot

   Explanation: Phoma terrestris causes characteristic pink to purple root coloration. Smut disease typically produces dark spore masses, not pink roots. Blue mold and Penicillium rot mainly affect bulbs in storage, not field roots.