When both mating types exist within a population, chleistothecia can form and are visible as small, black dots on the undersides of leaves.

[citation needed] Podosphaera macularis overwinters on the soil surface in debris as fungal survival structures (chasmothecia) or as mycelia in plant buds.

When favorable conditions are encountered during early spring, the asci (sac-like structures) within chasmothecia will rupture and ascospores will be discharged.

Specifically, the favorable conditions for ascospore release include low light, excess fertility, and high soil moisture.

[7] Favorable environmental conditions for Podosphaera macularis fecundity include low sun exposure, soil moisture, and excessive fertilization.

[7] However, leaf wetness is not essential for the formation and germination of conidia, but rather slight rain has an indirect effect related to high humidity and low sun light.

[9] Since the life cycle mainly exists externally, with only haustoria inside the host, supra-optimal temperatures and low relative humidity are unfavorable parameters for germination, infection or sporulation of powdery mildew.

[8] Intense rain and wind periods that cause spores blown throughout the hop yard also prevent powdery mildew fecundity.

In addition, solar irradiation can kill released spores, but as hops grow, the sun can't penetrate the dense canopy.

[5] Cultural practices that can help prevent the disease include carefully monitoring water and nutrient, reducing initial inoculum, and removing basal growth.

[4] In this case, removing basal growth before flowering and applying a protectant fungicide with long-term residual action should be employed.

[11] Although the methods successfully limited disease development, the depressed market for hops couldn't sustain the expensive production costs ($1400/ha annually in 1998).

[11] In 2001, a contracting brewery rejected 50% of an aroma hop grown in Oregon because of cone browning after drying, resulting in an additional US $5 million in losses that year.

While more research is necessary to understand Podosphaera macularis and control, the current management system has returned economics to hop industry.

The germ tube of P. macularis plays an important role in determining the pathogen's viability, because it can penetrate its host in approximately 15 hours.

The spread is stopped by a hypersensitive response, which is often associated with the establishment of large callose and lignin deposits surrounding infected cells.