Reduced amount of green pigment resulting in pale-yellow color; common causes include lack of light or minerals. This condition is called:

• A. Chlorosis
• B. Necrosis
• C. Wilting
• D. Senescence

Answer: (A)

Chlorosis occurs when leaves lose much of their green color because there’s less chlorophyll, the pigment essential for photosynthesis. When a plant doesn’t get enough light, or when nutrients required to make chlorophyll are missing—most notably iron, and sometimes magnesium or nitrogen—chlorophyll production drops and the leaves turn pale yellow. In turfgrass, this often shows up as pale-yellow areas on the blades, and iron deficiency can produce interveinal chlorosis, where the tissue between the veins is pale while the veins remain greener. Other conditions describe different problems: necrosis means tissue death, wilting indicates water stress, and senescence is aging and seasonal color change. So the pale-yellow, chlorophyll-deficient symptom described is chlorosis.