RA 00110.pdf - OAR@ICRISAT

Pearl millet should find a place in irrigated dry areas,
which could double and stabilize production with
minimum inputs. Pearl millet can be successfully
raised during the summer under irrigation.
In experiments under the A l l India Coordinated
Millets Project, pearl millet hybrids produced 15-
44% more grain under irrigation than under rainfed
conditions (1400-1840 kg ha -1 ) (Harinarayana 1980).
Irrigated CJ 104 (5054 A x J 104) yielded 44% more
than in the rainfed trial, while BJ 104(5141A x J 104)
yielded only 30% more grain under irrigation, indicating
female differences in water use. Similarly,
differences due to males are discernible in the
hybrids BD 111 (5141A x D 111) and BK 560 (5141 A
x K 560), revealing selection potential for water
input.
Salt tolerance. Uncontrolled and indiscriminate
irrigation and poor drainage are increasing soil
salinity. Understanding the physiology of salt tolerance
and adaptation mechanisms will undoubtedly
facilitate the development of management techniques
for saline soil and water. The effects of salinity
on germination, growth, and yield of pearl millet
need critical investigation. Pearl millet hybrids appear
to be more tolerant to salinity than populations
( A I C M I P 1979). Among the hybrids, the grain yield
of CO 2 was 14 g r o w - 1 as against 161 g of PHB 14
and 28 g of BJ 104, indicating the existence of genetic
variability for salt tolerance.
Tolerance to micronutrients. Alkaline soils occur
in subhumid, semi-arid, and arid climates, and are
well suited to small-grain agriculture. Plants grown
in alkaline, acid, or saline soils accumulate unwanted
minerals that limit root growth and nutrient uptake.
Alkaline soils are deficient in iron and high in
sodium and boron, while acid soils are high in aluminum.
The development of wheat varieties well
suited to very acid, high-aluminum soils in Brazil
indicates varietal differences in tolerance to toxins.
N, P, and K uptake. Variations were observed in
pearl millet fertilizer requirements, uptake, and utilization.
Nitrogen utilization from applied fertilizer
was highest in HB 4 when compared to HB 3 and HB
1. The utilization of soil N by HB 4 was intermediate
between that of HB 3 and HB 1, while the N
requirement to produce 100 kg grain was minimal.
Since the female parent (Tift 23A) was common to
all these hybrids, the N utilization differences are
conceivably attributable to the male parents, K 560,
J 104, and B I L 3B (B. Rama Moorty, Indian Agricultural
Research Institute, New Delhi, personal
communication).
These genotypes exhibit differential responses to
fertilizer input, and different production potentials
at different fertility levels indicates that the genotypes
have different threshold responses. Germplasm
and breeding material in advanced stages
should be evaluated under different fertility levels.
Input Management
Biofertilization. Bacterial fertilization has been
found to affect consumption of recommended inorganic
nitrogen. Azospirillum application alone increased
grain yield from 1115 to 1434 kg ha -1 (Harinarayana
1980). The effect varies depending on
location, p H , C:N ratio, and supplemental nitrogen
application. Azospirillum with 10 kg ha -1 N has
yielded as much grain as 20 kg ha -1 N, indicating that
10 kg ha -1 N could be saved. Azospirillum production
should be commercialized on the lines of Rhizobium
and applied extensively to increase pearl
millet grain yield with or without the addition of
inorganic nitrogen. More efficient strains better
compatible with specific genotypes, and factors,
both plant and bacterial, responsible for this specificity
should be identified for large-scale screening.
The rhizosphere bacteria are influenced by mycorrhizae
which increase the uptake of phosphorous,
even in soils with threshold levels (Hubbell 1987).
Studies to identify associative mycorrhizae beneficial
to pearl millet in poor soils would be useful.
Cropping systems approach. The ever-increasing
demand for food puts a premium on increasing food
production per unit area. The traditional mixed
farming systems have been scientifically transformed
into intercropping systems which include pearl millet.
The total system needs modifications based on selection
of genotypes for plant habit, plant height,
maturity, manipulation of ratio and proportion of
component crops, and management of production
components such as fertilizer, water, weeds, etc.
Graded technology. The adoption levels of improved
technology vary depending on farm size, and
farmer financial and technical resources. Field experience
shows that technology based on low monetary
inputs such as the introduction of high-yielding varieties
and improved cultural practices has been
widely adopted by all classes of farmers. However,
graded technology is necessary to suit the varying
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