Root Anatomy and Structure

• Roots develop from the central portion of the rhizome. They gradually move through the rhizome cortex until they emerge through or between nodes. All banana plant roots contain epidermis, exodermis, mesodermis, central cylinder and root-cap tissues. Root continue to grow and develop over their lifespan. Roots begin differentiation into secondary and tertiary roots when a new rhizome is formed.
  
  

Root Growth

• Banana plant root growth will orient toward fertile areas of the soil that have high concentrations of organic matter. Growth rate will vary with seasonal leaf emergence, as well as soil porosity, depth and natural fertility. Growth is typically noticeably slower in soil with a low pH, less than optimal temperatures or in areas with a high water table. The functional lifespan of a banana plant's main roots is five to eight months. During their life, roots can grow as much as 1-1/2 inches per day. Overall, roots in sandy soil tend to grow longer than roots in heavier clay soil. Based on an average 5-month lifespan, a well-maintained root system can extend as much as 24 feet from the stem of the plant.
  
  

Root Distribution

• While roots grow and spread long distances over their lifespan, approximately 90 percent of the roots can be found within 3 horizontal feet of the plant, while 70 percent of the roots are limited to the upper 15 inches of the soil. The root mass of the plant decreases with soil depth and soil fertility. For the most part, organic matter, which is the source of essential plant nutrients, is near the soil surface. As a result, most roots gravitate toward the surface.
  
  

Root Deterioration

• Several factors can cause banana root deterioration. A fast collapse, which takes place over days or months, often stems from severely restricted soil depth, extreme sand or clay soil types or high sodium concentrations. Slower deterioration may occur in sites that possess similar problems, but to a lesser degree. Poor disease control and a general lack of beneficial soil organisms may also harm roots. Reduced fruit yields are likely to occur if roots are weakened. Unless site improvements are made to improve root conditions, the whole plant can eventually die.