The deficiency of boron results in all except

Options

A. top sickness
B. browning of head in cauliflower
C. internal cork of apple
D. marsh spot disease

Answer

### Step-by-Step Solution:

1. **Understanding Boron Deficiency**: Boron is an essential micronutrient for plants, playing a critical role in cell wall formation and overall plant health. Deficiency in boron can lead to various physiological disorders in plants.

2. **Identifying the Options**: The question presents four options related to the effects of boron deficiency:
- A. Tooth sickness
- B. Browning of head in cauliflower
- C. Internal cork of apple
- D. Mars spore disease

3. **Analyzing Each Option**:
- **Tooth Sickness**: This condition is associated with boron deficiency, particularly in tobacco plants, where it manifests as a variety of symptoms.
- **Browning of Head in Cauliflower**: This is also a result of boron deficiency, as boron is crucial for healthy cell development in plants.
- **Internal Cork of Apple**: This disorder occurs due to boron deficiency, leading to lesions in the internal part of the apple.
- **Mars Spore Disease**: This disease is not caused by boron deficiency; instead, it is associated with manganese deficiency, particularly in pea plants.

4. **Conclusion**: The only option that does not result from boron deficiency is **Mars spore disease**. Therefore, the correct answer is option D.

### Final Answer:
**The deficiency of boron results in all except Mars spore disease.**

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