Battle Against Wheat Fungi Quiz

Explore essential wheat disease management practices to minimize fungal outbreaks and ensure healthy crop yields. Learn to identify symptoms, control strategies, and fungicide applications in modern agriculture.

1. Identifying Wheat Leaf Rust

   A wheat farmer notices small, reddish-brown pustules on the leaves in early summer; which disease is most likely affecting the crop?

   1. Leaf rust
   2. Powdery mildew
   3. Fusarium head blight
   4. Karnal bunt

   Explanation: Leaf rust is characterized by reddish-brown pustules on leaves, especially under warm and humid conditions. Powdery mildew appears as a white powdery coating, not rust-colored spots. Fusarium head blight mainly affects wheat heads, showing bleaching and mold. Karnal bunt affects kernels and produces a fishy smell, but not leaf pustules.

2. Fungicide Timing for Septoria

   When treating a wheat field for Septoria leaf blotch, at what crop growth stage is a fungicide spray usually most effective?

   1. Flag leaf emergence
   2. Flowering
   3. After harvest
   4. Seedling stage

   Explanation: Spraying fungicides at flag leaf emergence protects the most yield-contributing leaves and is recommended for Septoria control. Post-harvest applications are ineffective as the disease has already caused damage. Seedling stage applications are rarely needed for Septoria. Spraying at flowering is more relevant for head diseases like Fusarium.

3. Crop Rotation Benefits

   How can crop rotation help manage take-all disease in wheat fields?

   1. Increases soil acidity, killing pathogens
   2. Makes wheat more resistant to rust
   3. Reduces pathogen buildup by interrupting the disease cycle
   4. Eliminates all weed competition

   Explanation: Crop rotation with non-host crops interrupts the take-all fungus's lifecycle, lowering soil inoculum. It does not directly change soil acidity, which may affect other diseases. Resistance to rust is a separate genetic trait, and weed management is not the primary function of rotation for take-all control.

4. Resistant Wheat Varieties

   Why is planting disease-resistant wheat varieties recommended as a core management strategy for fungal diseases?

   1. They slow disease spread and require fewer fungicide applications
   2. They guarantee 100% disease immunity
   3. They mature faster than susceptible varieties
   4. They withstand drought conditions better

   Explanation: Disease-resistant varieties help limit fungal development and may reduce the need for fungicides, making management more sustainable. While some may mature at different rates, speed of maturity is not the main benefit. No variety offers absolute immunity. Drought tolerance is a different trait.

5. Understanding Fusarium Head Blight Symptoms

   Which symptom best indicates that wheat is affected by Fusarium head blight?

   1. Dark yellow leaf spots only
   2. Glossy green leaves
   3. Black powder inside kernels
   4. Bleached spikelets with pink or white fungal growth

   Explanation: Fusarium head blight typically results in blighted (bleached) spikelets, sometimes accompanied by pink or white mold on the head. Dark yellow spots are not specific to Fusarium head blight. Black powder inside kernels is characteristic of bunt diseases. Glossy green leaves indicate healthy plants.