Agriculture Reference
In-Depth Information
The set of responses to treatment with alkanolamines was bound to plants grown under
(non-specific) stress conditions. Plants grown in the absence of stress factors did not respond
to the treatments.
4.
P
RODUCTIVITY OF
C
EREALS UNDER
S
TRESS
C
ONDITIONS
IN
F
IELD
T
RIALS
The grain yield of spring barley grown on field plots over 3 yr varied considerably with
the water supply (Table 3, Bergmann et al. 1983). Drought stress control by treatment with
EA compensated for the declining productivity with yield increases from 1 to 22.6 % (60 to
970 kg/ha) with a mean of 10.4 % (557 kg/ha) over the test period. Increases in grain yield
correlated with the higher density of fertile ears/m
2
and were thus accompanied by an
elevated straw output (Table 3). The gains in productivity during dry seasons went along with
an improved water use efficiency of EA treated plants. Grain yield increases of 15 to 23 %
per L of rainwater under semi-arid conditions (Table 3) had been confirmed by pot trials
(Bergmann et al. 1983). In addition, shoot applications of EA stimulated the formation of root
biomass in cereals (Bergmann et al. 1998; Lippmann et al. 1998) and tomato (Grimmer 1998)
and retarded losses in chlorophyll (Bergmann et al. 1999; Horvath and van Hasselt 1985;
Wejnar 1989).
Large-scale applications of alkanolamines under the variable conditions of 17
Experimental Agrostations in East Germany resulted in local yield improvements from 5 to
20 % with means up to 11 and 13 %, respectively, in barley and rye (Table 4; Bergmann et al.
1999). Comparable effects were recorded for 53 field trials of wheat with relative grain yield
increases up to 20 % under unfavourable climate or soil conditions. Figure 5 relates the
productivity of wheat to soil type and the intensity of drought stress at five Experimental
Stations in East Germany. Significant yield improvements were bound to a pronounced
drought stress and were more reproducible by the use of choline chloride instead of EA.
Table 3. Grain and straw production (kg/ha) and water use efficiency of the spring
barley cultivars Trumpf and Lada on field plots 25 m
2
(6 replicates per treatment)
established on clay-chernozem soil under semi-arid conditions
Water use efficiency
b
Precipitation
deficit
a
(mm)
Grain yield (kg/ha)
Straw yield (kg/ha)
Stand density
(ears/m
2
)
Untreated
EA-appl.
Untreated
EA-appl.
Untreated
EA-appl.
Untreated
EA-appl.
-32.5
5980
6040
ND
ND
ND
ND
ND
ND
-62.5
6230
6670
ND
ND
ND
ND
ND
ND
5870
c
1.45
c
-93.2
5110
3440
3640
ND
ND
1.26
5260
c
3960
cd
640
c
1.78
c
-180.2
4290
3450
460
1.45
ND, not determined.
a
Difference between precipitation and evapotranspiration from April 1 to July 20.
b
Grain yield in g per L of rainwater.
c
Values significantly (
p
< 0.05) different from those of untreated controls.
d
Application of EA did not alter length and diameter of sprouts. Cultures were treated with
ethanolamine (3 kg/ha) at the outset of shooting. The tests were conducted by Experimental Station
Straussfurt, Thuringia, Germany, in 1977, 1978, and 1981. Adapted from Bergmann et al. (1983).
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