Homograft materials are extensively used in various surgical procedures in otolaryngology, but with the increasing prevalence of human immunodeficiency virus (HIV) in the population this practice must be reviewed. Careful donor selection and antibody testing reduce but do not fully eliminate the risk of an HIV positive donor, and current preservation techniques may not inactivate all viruses. The use of homograft tissues should therefore be reconsidered as autograft or prosthetic material provides a satisfactory alternative in many cases.

Phytophthora root rot, caused by many Phytophthora species, decreases the health of rhododendrons produced in nurseries. Optimizing nitrogen (N) fertilizer is often used to improve nursery stock quality, but there is little information on how N fertilizers influence root rot caused by these pathogens. To understand the impact of N fertilizer and pathogen species on root rot development, rhododendrons were grown with no (0 g N/pot), low (1.04 g N/pot) or high (3.12 g N/pot) rates of N and inoculated with either P. cinnamomi or P. plurivora. Noninoculated plants at low and high N rates had greater biomass, leaf greenness and enhanced N, potassium, magnesium, phosphorus, sulphur and manganese uptake compared to plants grown with no N. When either Phytophthora species was present, N application increased aboveground disease symptoms (wilting, chlorosis, reduced stomatal conductance and biomass), but had no effect on root rot severity belowground. In addition, P. cinnamomi restricted uptake of several nutrients while P. plurivora had less influence on nutrient uptake. Nurseries frequently apply high amounts of N to promote fast growth. However, our results show that this can exacerbate root rot when P. cinnamomi or P. plurivora is present. Although decreasing N can reduce the number of overtly symptomatic plants, this may conversely increase the risk for selling apparently asymptomatic plants with low levels of infection. Additional studies are needed to determine how N fertilization influences Phytophthora root rot for a broader range of rhododendron cultivars and nursery crop species.