RA 00048.pdf - OAR@ICRISAT

Inter- and Intraspecific Competition and the Design of Productive
Cropping Systems
B. S. Rana, P. P. Tarhalkar. and N. G. P. Rao
Abstract
Competition between species results in their characterization as complementary, aggressive or relatively neutral
species. Alteration of plant type within a species renders them more-or-less competitive. Data on inter- and
intraspecies competition with sorghum as a component crap will be presented. Keeping in view the recent changes
that have occurred in sorghum cultivars, the complementarity or compatibility of sorghum-based cropping systems
both in space and time will be examined. The design and development of stable, productive and transgressive
cropping systems will be analyzed.
Factors Affecting Sorghum Consumption in Honduras
Mary Futrell, Eunice McCulloch, Robert Jones, and Louis Bluhm
Abstract
This interdisciplinary research dealt with the agronomic, economic, social and nutritional factors which influenced the
production, storage, and consumption of sorghum in Honduras. An interview schedule covering the above areas was
developed and used by Mississippi INTSORMIL researchers in two surveys in the summer of 1981 in mountainous
and lowland areas of southern Honduras. Data on household size, sex roles, decision-making patterns, attitudes,
values, consumer preferences of grain and methods of food preparation were recorded. Food intake studies, as well
as anthropometric measurements, were used to assess the nutritional status of each child. This was a base-line study
to develop criterion for future nutritional improvement through the use of improved strains of sorghum grown in
Honduras for human consumption.
Nitrogen Fixation Associated with Sorghum
S. P. Wani, P. J. Dart, S. C. Chandrapalalah, and M. N. Upadhyaya
Abstract
Using a soil-core assay method in the acetylene reduction technique, 334 lines have been screened; 5 5 % of the lines
tested stimulated N 2 -ase activity in the rhizosphere and 14% stimulated high activity (100 µg N/core/day). The activity
is affected by field variability, time of sampling during the day, and the time interval between taking the core and
injecting C 2 H 2 . Activity varied not only with the growth stage of the crop when assayed, but also with the temperature
at which the cores were incubated during assay and the amount of nitrogen fertilizer added. Activity is well correlated
with the soil moisture. A test tube culture technique has been developed to test the effect of host genotype and
bacterial culture on nitrogenase activity. A method for assaying intact plants for nitrogenase activity has been
developed. By using this method the same plant can be assayed several times during its growth cycle and seed can
also be obtained. In a pot experiment with the sorghum hybrid CSH-1 grown in unsterilized Alfisol soil, inoculation with
nitrogen fixing bacteria produced a significant increase in grain and total dry matter production.
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