DISEASES OF ALFALFA - COMMON LEAF SPOT

Alfalfa is affected by several leaf pathogens that can cause a range of necrotic spot symptoms. In general, the spotting diseases are difficult to distinguish from one another. Some common spotting diseases include spring black stem (discussed in detail in the previous slide), common leaf spot and Stemphylium leaf spot. Common leaf spot (shown in this photo) is caused by the fungus Pseudopeziza medicaginis. This fungus causes small (~1/8 in diameter) spots, that often have a raised bump (a fungal fruiting body) in the center.