Use of High Temperature to Increase the Rate of Avocado Sunblotch Symptom Development in Indicator Seedlings. J. V. Da Graça, Lecturer, Department of Microbiology and Plant Pathology, University of Natal, Pietermaritzburg, South Africa. S. P. Van Vuuren, Control Technician, Citrus and Subtropical Fruit Research Institute, Nelspruit, South Africa. Plant Dis. 65:46-47. Copyright 1981 American Phytopathological Society. DOI: 10.1094/PD-65-46.

Avocado sunblotch symptoms in Collinson indicator seedlings developed significantly faster in a hot (30/28 C, day/night) than in a cool (20/18 C, day/night) glasshouse. When indicator plants were cut back 3 mo instead of 6 mo after inoculation, symptom development in plants inoculated with symptomless carrier sources of sunblotch was accelerated. Indexing for sunblotch can thus be completed in about 8 mo instead of 2 yr.