Stop the Rot! Garlic Fungus Quiz Quiz

Explore the key concepts of garlic disease management with a focus on fungal threats, symptoms, and control strategies. This quiz helps reinforce essential knowledge for healthy garlic crops.

1. Identifying Garlic White Rot

   Which symptom best indicates white rot infection in a garlic field?

   1. Wilted plants with brown root tips only
   2. Yellowing leaves with fluffy white fungal growth at the stem base
   3. Black sunken lesions on leaf tips
   4. Purple streaks along the garlic cloves

   Explanation: White rot typically presents as yellowing of leaves accompanied by a distinct fluffy white fungal growth at the stem base. Purple streaks suggest varietal traits or unrelated disease, not white rot. Black sunken lesions are more typical of other fungal diseases like botrytis. Wilted plants with brown root tips mainly point to root rot, not specifically white rot.

2. Fungus Lifecycle Understanding

   What environmental condition most favors the development of Sclerotium cepivorum, the cause of garlic white rot?

   1. Acidic soils below pH 5
   2. Cool and moist soils
   3. Hot and dry conditions
   4. Dry and sandy soils

   Explanation: Cool, moist soils create ideal conditions for Sclerotium cepivorum to infect and thrive. Dry, sandy soils inhibit fungal spread by lacking moisture. Hot, dry conditions are unfavorable for white rot development. Soil pH below 5 is not mainly connected to white rot risk.

3. Disease Prevention Practices

   Which practice is most effective in preventing the spread of fungal diseases in garlic crops?

   1. Planting garlic in the same location every year
   2. Overhead irrigation in the late afternoon
   3. Sanitizing tools and removing infected plant material
   4. Applying high-nitrogen fertilizer before planting

   Explanation: Cleaning tools and removing infected debris prevent fungal spores from spreading between plants and fields. Overhead irrigation, especially late in the day, can increase disease risk by keeping leaves wet. Repeatedly planting garlic in the same spot builds up soil-borne pathogens. High-nitrogen fertilizer does not prevent fungal diseases and may even promote soft growth that is more susceptible.

4. Recognizing Fusarium Basal Rot

   A garlic grower notices bulbs with soft, tan decay and pinkish fungal growth at the base. Which disease is the most likely cause?

   1. Downy mildew
   2. Neck rot
   3. Rust
   4. Fusarium basal rot

   Explanation: Fusarium basal rot displays soft tan bulb decay and sometimes pinkish or white fungal growth at the base. Downy mildew mainly affects leaves, causing pale yellow patches. Neck rot typically occurs post-harvest around the stem. Rust shows up as orange pustules, not soft bulb decay.

5. Crop Rotation Strategies

   When managing garlic for fungus control, how long should growers avoid planting garlic or onions in the same soil after a white rot outbreak?

   1. 2 consecutive years
   2. Every third year
   3. 1 cropping season
   4. At least 4–7 years

   Explanation: Resting fields from host crops like garlic and onions for 4–7 years helps reduce persistent white rot sclerotia in soil. A single season or two years is often too short for effective control. Planting every third year is also usually insufficient after a major outbreak due to the fungus's long-lived spores.