Pryor Laboratory - Focusing on Lettuce Diseases, Mycology, and Alternaria at The University of Arizona School of Plant Sciences, Tucson, Arizona USA Disease management is a principle activity for growers of all types of lettuce. Viral, bacterial, and most importantly, fungal diseases can seriously impact quality and yield.

Lettuce Drop

Lettuce Diseases Placeholder

Among the important fungal diseases affecting lettuce, lettuce drop caused by Sclerotinia spp., is one of the most common and destructive diseases resulting in yearly losses in all lettuce-producing regions for all types of lettuce (Wu and Subbarao, 2006: Phytopathology 96:1322-1329). Crop losses may vary from 1 % to nearly 75%, and in some cases entire field may be lost (Chitrampalam et al 2008. Plant Dis. 92:1625-1634).

Repeated cultivation of lettuce and repeated occurence of lettuce drop in Arizona and California results in increased accumulation of lettuce drop pathogen in soil and increased disease incidence on proceeding lettuce crops. Thus, improved management strategies for lettuce drop, including development of non-chemical treatments, will have direct benefits to lettuce growers in both states.