I - --ii

ules and the nodule mass for both winter- and spring-planted crops. However, all
strains of Rhizobium resulted in more nodules and nodule mass during the winter
season than in spring, in both years. Although some strains caused very good
nodule development in the winter season, these failed in spring. Some strains of
Rhizobium (for example, IC-26 and Cp-5b) performed well during both winter
and spring season. Even these strains produced only 35-75% nodule mass in
spring as compared to the winter. It was also observed that in winter the plants
formed more primary nodules and the secondary nodules were well distributed in
the root system, whereas the spring-planted crop had fewer primary nodules
which were located only in a portion of the roots immediately below the surface.
This possibly resulted from the differences in the availability of moisture and/or
soil temperatures during the two seasons. Application of inorganic nitrogen
fertilizer to the plants considerably reduced the nodule mass development.
The drymatter production reflected the nodule development pattern of the
plants (Table 1). Irrespective of the treatments, the plants produced more dry
matter in the winter than in the spring. In the 1979-80 growing season, the plants
generally formed more nodule tissues and total dry matter than in 1978-79,
possibly because of more rainfall.
The winter-planted crop also produced more grain during 1978-79 than the
spring-planted crop, i.e. 33-66% more, depending on the Rhizobium strain.
Reliable yield data could not be obtained during the 1979-80 growing season
because the winter-planted crop was severely damaged at the pod filling stage by
ascochyta blight, in spite of repeated spraying with fungicides, and the springplanted
crop was damaged by birds at the early seedling stage.
These results indicate that planting chickpeas in winter results in better nodulation,
possibly because of more available moisture in the soil profile. Better
nodulation might partly be responsible for higher grain yield in winter-planted
chickpeas.
Response to Inoculation with Single, Double and Multiple Strains of
Rhizobiurm
The results described above showed that artificial inoculation greatl: increased
both nodulation and yield of winter-planted chickpeas. However, the growing
season of winter-planted chickpea is characterized by two contrasting weather
conditions, i.e. very cold wet weather at early vegetative stage which changes
rapidly to hot dry weather during pod filling and maturity stage. It was thus
thought necessary to compare the performance of single versus multiple strains
of chickpea Rhizobium. Accordingly, during 1978-79 growing season three
strains of Rhizobium (3827, Ca-7 and IC-26) were used either singly or in
combination with ILC 1929 chickpeas planted in winter (Islam 1980).
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