This study determined whether the tolerance of yellow lupin to waterlogging,
observed in experiments in controlled environments, occurs under field
conditions. Of particular interest is the impact of waterlogging on the
distribution of roots because lupin is exposed to terminal drought in the
south of Western Australia, which in itself can have a profound effect on
yield. A field experiment was undertaken in the central grain-growing region
of Western Australia near Beverley using hydraulically isolated plots to
impose and remove waterlogging in a duplex soil. The responses of root and
shoot growth of narrow-leafed and yellow lupin to waterlogging in the field
were similar to those observed in the controlled environment experiments. In
the field experiment, waterlogging had no effect on seed yield of yellow lupin
but reduced it by 61% in narrow-leafed lupin. Waterlogging more than
halved the dry weight of narrow-leafed lupin but reduced it by only 19%
in yellow lupin. In yellow lupin, yield was 3.4 t/ha with waterlogging and
3.8 t/ha without waterlogging, compared with 1.4 t/ha with
waterlogging and 3.5 t/ha without waterlogging in narrow-leafed lupin.
Waterlogging had no effect on the harvest index of yellow lupin (0.26) but
reduced it from 0.36 to 0.31 in narrow-leafed lupin. The larger effect of
waterlogging on the yield of narrow-leafed lupin was mainly attributable to
fewer pods.
Net root growth ceased during waterlogging in both species. After
waterlogging, roots of yellow lupin grew at a similar rate to the controls,
whereas roots of narrow-leafed lupin grew at a much slower rate than the
controls. Waterlogging halved the root density of yellow lupin at 25 cm depth
and almost eliminated the roots of narrow-leafed lupin at this depth. After
waterlogging, root production in the surface 10 cm increased to about 0.5
cm/cm 3 in yellow lupin but to 0.2 cm/cm
3 in narrow-leafed lupin. At depth (>20 cm), roots of
waterlogged yellow lupin continued to grow while those of waterlogged
narrow-leafed lupin grew little, if at all. Yellow lupin tolerated
waterlogging in the field better than narrow-leafed lupin because it
re-established its root system at depth after waterlogging was removed and it
produced more fertile pods.
A Study Of Corporate Venturing And Sustainability Of First Mover Advantages During Technological Disruption In The U.S. Mobile Wireless Data Industry
