HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text (PDF) Alert me when this article is cited Alert me if a correction is posted Services Similar articles in this journal Alert me to new issues of the journal Download to citation manager Citing Articles Citing Articles via Google Scholar Google Scholar Articles by Caldwell, B. E. Articles by Weber, D. F. Search for Related Content PubMed Articles by Caldwell, B. E. Articles by Weber, D. F. Agricola Articles by Caldwell, B. E. Articles by Weber, D. F.

Distribution of Rhizobium japonicum Serogroups in Soybean Nodules as Affected by Planting Dates¹

The soybean variety ‘Lee’ was planted at different dates for 3 successive years in Codorus silt loam soil containing an established population of Rhizobium japonicum. The soil was not reinoculated. Nodules were collected from each of the treatments and classified into the appropriate serogroup. The occurrence of specific serological groups was influenced by planting date. Serogroup c3 was greater in the late planting dates in 2 years and serogroup c2 increased the third year. Serogroup 110, and the composite serogroups 122 to 125 were at their maximum for the earliest planting dates. The serological distribution also differed when nodules were sampled from plants at different stages of development. The serological variation in planting date was attributed to the different soil and climatic environments and indicated the influence of the environments on the ecology of the Rhizobium.

Key Words: Inoculation • Nodulation • Nitrogen fixation • Glycerin max.

² Research Agronomist, and Microbiologist, respectively, Soybean Investigations, Crops Research Division, Agricultural Research Service, U. S. Department of Agriculture, Beltsville, Maryland, 20705.

Received for publication May 19, 1969.