Ali Cala, Nathalia Portilla, Bill Weldon, William Gura, Nicholas King, George Stack, Jacob Toth, Craig Carlson, David Gadoury, Surya Sapkota, Larry Smart, Chris Smart
Hemp powdery mildew – Golovinomyces spadiceus:
- Hemp powdery mildew is a fungal pathogen that appears as patches of white spores on the surface of leaves (Fig. 1 & 2).
- It is an emerging pathogen – has been reported in greenhouses and the field.
- It can cause early leaf drop & reduce flower bud quality (Fig. 3).
- Disease management strategies for hemp powdery mildew are being developed.
Is there resistance to powdery mildew in hemp?
- 30 high CBD cultivars were screened for resistance to powdery mildew
- Preliminary data from the detached leaf assay showed some differences in susceptibility (Fig. 4).
- These studies are continuing, and we are screening an additional 37 cultivars.
Is Hemp Powdery Mildew & Hop Powdery Mildew cross infectivity a concern?
- Humulus lupulus (hop)? is the closest crop relative to hemp.
- Hop powdery mildew is caused by Podosphaera macularis (Fig. 5 & 6).
Is hemp powdery mildew a threat to hop?
Is hop powdery mildew a threat to hemp?
Can we identify resistance genes in hemp against powdery mildew? Which cultivars are most resistant? How diverse is the pathogen population?