Persistence of Rhizobium japonicum on the Soybean Seed Coat Under Controlled Temperature and Humidity.

When Rhizobium japonicum strain 61A68 was added to surface-sterilized soybean (Glycine max) seed along with 12 different coating materials, a definite effect of temperature upon survival was observed both with and without coating materials. At a storage temperature of 15 degrees C and 50 +/- 5% relative humidity, from 0.9 to 14.1% of the original inoculum survived for 3 weeks. At 22.5 degrees C, from 0.5 to 7.2% of the original inoculum survived. At 30 degrees C, from 0.1 to 1.6% of the original inoculum survived. The data indicated that extremely large numbers of R. japonicum would have to be added to the seed to have numbers adequate for nodulation survive for 3 weeks of storage at ordinary temperatures.