VIEW ARTICLE

Techniques

Inoculation of Soybean Plants by Injection with Zoospores of Phytophthora megasperma var. sojae. F. W. Schwenk, Department of Plant Pathology and Agronomy, Kansas State University, Manhattan, KS 66506; C. A. Ciaschini(2), C. D. Nickell(3), and D. G. Trombold(4). (2)(3)(4)Departments of Plant Pathology and Agronomy, Kansas State University, Manhattan, KS 66506. Phytopathology 69:1233-1234. Accepted for publication 23 May 1979. Copyright 1979 The American Phytopathological Society. DOI: 10.1094/Phyto-69-1233.

Suspensions of Phytophthora megasperma var. sojae zoospores were injected into the hypocotyls of soybean plants. This method took one-third to one-quarter the time required for hypocotyl inoculation with agar pieces bearing mycelium. When 10⁵ zoospores per milliliter were used, the results of the two methods were nearly identical, and intervals between inoculation and reaction determination were similar under greenhouse conditions. Plants grown at 28 C under continuous light in controlled environment chambers could be inoculated as early as 4 days after planting in vermiculite, and the disease reaction determined 3 days later.