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Persistence of rhizobia in some Philippine soils / Erlinda S. Paterno.

By:

Paterno, Erlinda S [author]

Contributor(s):

Tilo, Santiago N [adviser]

Material type: Text

TextLanguage: English Publication details: Los Baños, Laguna, 1979. Cavite State University- Main Campus,Description: 148 pages : illustrations ; 28 cmContent type:

text

Media type:

unmediated

Carrier type:

volume

Subject(s):

DDC classification:

631.4 P27 1979

Online resources:

Click here to view thesis abstract and table of contents

Abstract: Paterno, Erlinda S., University of the Philippines at Los Banos, April, 1979. Persistence of Rhizobia_in Some Philippine Soils. Major Professor: Dr. Santiago N. Tilo. The behaviour of rhizobia in soils under different conditions was studied using streptomycin resistant mutants. Rhizobium japonicum strains CB 1809 and S-38 were tested on soybean variety UPL SY-2, Rhizobium sp. strains M-4 and M-5 on mungbean variety CES 1D-21 and Rhizobium sp. strains CB 81 and L on ipil-ipil varieties K-8 and Peruvian. All strains tested were able to survive and infect the host plant in Luisiana clay (pH 4.5), Lipa clay loam (pH 4.7), Antipolo clay (pH 5.1), Lipa clay loam (pH 6.2), Taal sandy loam (pH 6.4) and Binangonan clay (pH 7.5). The proportion of nodules formed by the inoculum strains was influenced more by competition with the indigenous rhizobial population than by soil pH. Limiting an acid soil to raise the pH from 5.1 to 6.5 and/or phosphorus application increased the proportion of nodules formed by the inoculum strains. Seed pelleting with a mixture of lime and superphosphate appeared to be beneficial only for strain M-5. In the absence of the host plant, the number of the introduced rhizobia decreased significantly in Lipa clay loam (pH 4.7) but not in Lipa clay loam (pH 6.2) and Binangonan clay (pH 7.5). At a soil moisture tension of 15 atmospheres less than one percent of the rhizobial population survived after 14 days while high population was maintained at a soil moisture tension of 1/3 atmosphere. The Rhizobium strains CB 1809, S-38, M-4 and M-5 persisted in soils under continuous legume and legume-rice-legume cropping patterns. The introduced rhizobia survived waterlogging and were able to infect the host plant. The inoculum strains produced a larger proportion of nodules when applied individually than in a mixture. Strains CB 1809, M-5 and CB &1 were found to be more effective competitors for nodule formation than strains S-38, M-5 and L, respectively. An actinomycete isolate was found to be antagonistic towards rhizobial strain CB 1809. No antagonistic bacteria and fungi were observed. Rhizobia were shown to be distributed away from the point of inoculation when moisture was sufficient.

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Holdings ( 1 )
Title notes ( 4 )

Holdings
Item type	Current library	Collection	Call number	Materials specified	URL	Status	Notes	Date due	Barcode
Theses / Manuscripts	Ladislao N. Diwa Memorial Library Theses Section	Non-fiction	631.4 P27 1979 (Browse shelf(Opens below))		Link to resource	Room use only	T-1539		00002377

Thesis (Ph.D. - - Soil Science) University of the Philippines, College, Laguna.

Includes bibliographical references.

Paterno, Erlinda S., University of the Philippines at Los Banos, April, 1979. Persistence of Rhizobia_in Some Philippine Soils. Major Professor: Dr. Santiago N. Tilo.

The behaviour of rhizobia in soils under different conditions was studied using streptomycin resistant mutants. Rhizobium japonicum strains CB 1809 and S-38 were tested on soybean variety UPL SY-2, Rhizobium sp. strains M-4 and M-5 on mungbean variety CES 1D-21 and

Rhizobium sp. strains CB 81 and L on ipil-ipil varieties K-8 and
Peruvian.

All strains tested were able to survive and infect the host plant in Luisiana clay (pH 4.5), Lipa clay loam (pH 4.7), Antipolo clay (pH 5.1), Lipa clay loam (pH 6.2), Taal sandy loam (pH 6.4) and Binangonan clay (pH 7.5). The proportion of nodules formed by the inoculum strains was influenced more by competition with the indigenous rhizobial population than by soil pH.

Limiting an acid soil to raise the pH from 5.1 to 6.5 and/or phosphorus application increased the proportion of nodules formed by the inoculum strains. Seed pelleting with a mixture of lime and superphosphate appeared to be beneficial only for strain M-5.

In the absence of the host plant, the number of the introduced rhizobia decreased significantly in Lipa clay loam (pH 4.7) but not

in Lipa clay loam (pH 6.2) and Binangonan clay (pH 7.5). At a soil moisture tension of 15 atmospheres less than one percent of the rhizobial population survived after 14 days while high population was maintained at a soil moisture tension of 1/3 atmosphere.

The Rhizobium strains CB 1809, S-38, M-4 and M-5 persisted in soils under continuous legume and legume-rice-legume cropping patterns.

The introduced rhizobia survived waterlogging and were able to infect the host plant.

The inoculum strains produced a larger proportion of nodules when applied individually than in a mixture. Strains CB 1809, M-5 and CB &1 were found to be more effective competitors for nodule formation than strains S-38, M-5 and L, respectively.

An actinomycete isolate was found to be antagonistic towards rhizobial strain CB 1809. No antagonistic bacteria and fungi were observed. Rhizobia were shown to be distributed away from the point of inoculation when moisture was sufficient.

Submitted to the University Library 10/26/1993 T-1539