Certified Professional Horticulturist (CPH) Practice Exam

Which is a common sign of nutrient deficiency in plants?

1. Wilting leaves

2. Pest infestations

3. Yellowing of leaves

4. Branched stems

The correct answer is: Yellowing of leaves

Yellowing of leaves is a common sign of nutrient deficiency in plants and is often referred to as chlorosis. This phenomenon occurs when plants lack essential nutrients like nitrogen, iron, or magnesium, which are vital for chlorophyll production and overall plant health. When the specific nutrient is in short supply, the leaves can lose their green color and may turn yellow. In the case of nitrogen deficiency, for example, older leaves are typically affected first, while iron deficiency often impacts younger leaves. Recognizing this symptom is crucial for diagnosing health issues in plants and determining the necessary amendments to the soil or growing conditions to correct the deficiency. Other signs mentioned are indicative of different issues. Wilting leaves can suggest insufficient water or root problems. Pest infestations usually manifest through visible signs of damage such as holes in leaves or sticky residues. Branched stems can occur due to various reasons, including environmental factors or genetic traits, but do not specifically denote nutrient deficiencies. Understanding these differences helps in proper plant care and management.