29 research outputs found
Effect of water availability pattern on yield of pearl millet in semi-arid tropical environments
Throughout much of the semi-arid tropics, fluctuations in grain yield can largely be attributed to differences in timing and intensity of drought stress. Since seasonal rainfall in these environments is often poorly related to grain yield, the aim of this paper was to establish a relationship between water availability and grain yield for pearl millet (Pennisetum glaucum (L.) R. Br.), grown across 24 semi-arid tropical environments in India. We used a simple soil water budget to calculate a water satisfaction index (WSI) throughout the season. The cumulative WSI at maturity explained 76% of the variance in grain yield. This was three times as much as explained by actual rainfall, because WSI accounted for differences in water losses and pan evaporation. A classification of environments into four groups of water availability patterns explained 75% of the environmental sum of squares for grain yield. For a subset of 13 environments, environmental differences in grain number could also be explained by water availability patterns, whereas differences in grain mass were related to both water availability and temperature. Our results indicate that cumulative WSI, which is an integrated measure of plant-available water, can provide an adequate estimation of the environmental potential for yield in environments where grain yield is mainly limited by variable availability of water
Multispectral-Fluorescence Imaging as a Tool to Separate Healthy from Disease-Related Lymphatic Anatomy During Robot-Assisted Laparoscopy
Prostatic carcinom
Adaptation of barley (Hordeum vulgare L.) to harsh Mediterranean environments. 3. Plant ideotype and grain yield.
Adaptation of barley (Hordeum vulgare L.) to harsh Mediterranean environments. 1. Morphological traits.
Adaptation of barley (Hordeum vulgare L.) to harsh Mediterranean environments. 2. Apical development, leaf and tiller appearance.
Not Available
Not AvailableThere is evidence that high-tillering, small-panicled pearl millet landraces are better adapted to the severe, unpredictable drought stress of
the arid zones ofNWIndia than are low-tillering, large-panicled modern varieties, which significantly outyield the landraces under favourable
conditions. In this paper, we analyse the relationship of arid zone adaptation with the expression, under optimum conditions, of yield
components that determine either the potential sink size or the ability to realise this potential. The objective is to test whether selection under
optimal conditions for yield components can identify germplasm with adaptation to arid zones in NW India, as this could potentially improve
the efficiency of pearl millet improvement programs targeting arid zones. We use data from an evaluation of over 100 landraces from NW
India, conducted for two seasons under both severely drought-stressed and favourable conditions in northwest and south India. Trial average
grain yields ranged from 14 g m 2 to 182 g m 2. The landraces were grouped into clusters, based on their phenology and yield components as
measured under well-watered conditions in south India. In environments without pre-flowering drought stress, tillering type had no effect on
potential sink size, but low-tillering, large-panicled landraces yielded significantly more grain, as they were better able to realise their
potential sink size. By contrast, in two low-yielding arid zone environments which experienced pre-anthesis drought stress, low-tillering,
large-panicled landraces yielded significantly less grain than high-tillering ones with comparable phenology, because of both a reduced
potential sink size and a reduced ability to realise this potential. The results indicate that the high grain yield of low-tillering, large-panicled
landraces under favourable conditions is due to improved partitioning, rather than resource capture. However, under severe stress with
restricted assimilate supply, high-tillering, small-panicled landraces are better able to produce a reproductive sink than are large-panicled
ones. Selection under optimum conditions for yield components representing a resource allocation pattern favouring high yield under severe
drought stress, combined with a capability to increase grain yield if assimilates are available, was more effective than direct selection for grain
yield in identifying germplasm adapted to arid zones. Incorporating such selection in early generations of variety testing could reduce the
reliance on random stress environments. This should improve the efficiency of millet breeding programs targeting arid zones.Not Availabl
Not Available
Not AvailableThere is evidence that high-tillering, small-panicled pearl millet landraces are better adapted to the severe, unpredictable drought stress of
the arid zones ofNWIndia than are low-tillering, large-panicled modern varieties, which significantly outyield the landraces under favourable
conditions. In this paper, we analyse the relationship of arid zone adaptation with the expression, under optimum conditions, of yield
components that determine either the potential sink size or the ability to realise this potential. The objective is to test whether selection under
optimal conditions for yield components can identify germplasm with adaptation to arid zones in NW India, as this could potentially improve
the efficiency of pearl millet improvement programs targeting arid zones. We use data from an evaluation of over 100 landraces from NW
India, conducted for two seasons under both severely drought-stressed and favourable conditions in northwest and south India. Trial average
grain yields ranged from 14 g m 2 to 182 g m 2. The landraces were grouped into clusters, based on their phenology and yield components as
measured under well-watered conditions in south India. In environments without pre-flowering drought stress, tillering type had no effect on
potential sink size, but low-tillering, large-panicled landraces yielded significantly more grain, as they were better able to realise their
potential sink size. By contrast, in two low-yielding arid zone environments which experienced pre-anthesis drought stress, low-tillering,
large-panicled landraces yielded significantly less grain than high-tillering ones with comparable phenology, because of both a reduced
potential sink size and a reduced ability to realise this potential. The results indicate that the high grain yield of low-tillering, large-panicled
landraces under favourable conditions is due to improved partitioning, rather than resource capture. However, under severe stress with
restricted assimilate supply, high-tillering, small-panicled landraces are better able to produce a reproductive sink than are large-panicled
ones. Selection under optimum conditions for yield components representing a resource allocation pattern favouring high yield under severe
drought stress, combined with a capability to increase grain yield if assimilates are available, was more effective than direct selection for grain
yield in identifying germplasm adapted to arid zones. Incorporating such selection in early generations of variety testing could reduce the
reliance on random stress environments. This should improve the efficiency of millet breeding programs targeting arid zones.Not Availabl