Several fungal pathogens can manifest as a white, powdery growth on cannabis foliage, a condition known as powdery mildew. While multiple species can cause this infection, Golovinomyces cichoracearum and Podosphaera macularis are frequently implicated in outbreaks on cannabis crops. These obligate biotrophic parasites thrive by extracting nutrients from the living plant tissue, leading to reduced photosynthetic capacity and overall plant vigor.
The presence of powdery mildew presents a significant challenge to cannabis cultivators. Infections can diminish yield, compromise the aesthetic appeal of flower products, and, in severe cases, render the crop unsalable. Understanding the specific fungal agent involved allows for targeted treatment strategies, maximizing the effectiveness of control measures while minimizing the potential for resistance development. Historically, inaccurate identification led to broad-spectrum fungicide applications that had limited success and undesirable environmental consequences.