Protecting Apple Orchards Quiz Quiz

Assess your understanding of effective disease management strategies in apple orchard horticulture. This quiz covers common pathogens, prevention methods, and integrated pest management approaches for sustainable orchard health.

1. Apple Scab Identification

   Which symptom most reliably indicates the presence of apple scab disease on apple trees in early spring?

   1. Wilted stems with gummy exudate
   2. Olive-green, velvety spots on young leaves
   3. White, powdery residue on leaf surfaces
   4. Circular holes in fruit caused by insects

   Explanation: Apple scab typically begins as olive-green, velvety spots on young leaves, which later darken and affect fruit. Wilted stems with gum suggest bacterial or canker diseases, not apple scab. Holes in fruit are indicative of insect feeding, not fungal infection. A white, powdery residue signals powdery mildew rather than apple scab.

2. Sanitation Practices

   Why is removing fallen leaves and pruned branches considered a key practice in apple disease management?

   1. It directly improves fruit sugar content
   2. It reduces overwintering sites for disease-causing organisms
   3. It accelerates flower bud development
   4. It increases the soil's nutrient level significantly

   Explanation: Sanitation removes potential sources of infection, such as leaves and wood where pathogens may overwinter. Clearing debris does not significantly affect soil nutrient levels, fruit sugar content, or directly speed up flower bud development.

3. Fungicide Application Timing

   When is the most effective period to begin fungicide sprays for controlling primary apple scab infections in a temperate-region orchard?

   1. Only after severe leaf damage appears
   2. When fruit is nearly mature
   3. At green tip bud stage, before major leaf growth
   4. During mid-winter dormancy

   Explanation: Beginning fungicide sprays at green tip helps protect new, susceptible tissue just as primary infection is likely. Spraying after damage appears is less effective. Mature fruit is less at risk for first infections, and winter treatments are generally ineffective against apple scab.

4. Resistant Varieties

   How does planting disease-resistant apple varieties contribute to orchard disease management?

   1. It shortens the time to fruit harvest
   2. It guarantees a pest-free crop every season
   3. It doubles the need for irrigation
   4. It reduces reliance on chemical fungicides

   Explanation: Using disease-resistant varieties lessens the necessity for chemical applications, supporting sustainable practices. No variety is guaranteed completely pest-free. Resistance does not affect irrigation needs or fruit maturation times.

5. Cultural Control Measures

   Which orchard management practice best improves air circulation and limits disease spread among apple trees?

   1. Applying high-nitrogen fertilizer in early summer
   2. Planting trees as closely as possible
   3. Pruning tree canopies to open crowded branches
   4. Watering foliage in the late evening

   Explanation: Pruning reduces canopy density, which helps dry leaves quickly and prevents pathogen development. Evening watering keeps leaves wet overnight, increasing disease risk. Excess nitrogen can promote susceptible growth, and crowding trees hampers air flow.