Question

Internal cork of apple fruit develops due to the deficiency of

• A. Magnesium
• B. Iron
• C. Manganese
• D. Boron

Answer 1

The correct option is D Boron

Boron is a micronutrient which forms a component of plant cell wall and reproductive structures. Fruits such as apple show the formation of external as well as internal cork due to the deficiency of boron. External cork refers to the formation of surface spots while internal cork refers to the formation of lesions in the internal fleshy part. The external cork develops two weeks after petal fall and the spots appear water soaked at first. Later they become light brown and wrinkled with sap exudation from the surface. In mild cases of internal cork, there are no external symptoms but in severe form the external appearance of the fruit becomes rough. Internal cork affects the core area in which several brown corky spots of varying size appear.

Thus, the correct answer is option D.