source of low-cost protein that can be profitably utilized to supplement protein inadequacies in
cereals. As a N
2
fixing legume, it can also play a role in enhancing soil fertility.
Williams 1979 observed that weather condi- tions, cultivation management, soil nitrogen status,
and use of fertilizers accounted for about 95 of the variance in the protein content of wheat and
concluded that the amount of protein incorporated into wheat kernels was controlled, to a considerable
extent, by environmental factors. In addition, seed oil deposition is known to be affected by a range
of agronomic factors Canvin, 1965; Zhang et al., 1993, 1994. Shaw and Liang 1966 and Stone and
Turker 1969 found that maximum protein con- centration occurred in soybean seed when the crop
was water stressed during the pod filling stage. Stone and Turker 1969 also noted that severe
moisture stress during pod filling adversely affected both the oil and protein yield of soybean. Rose
1988 observed that the degree to which these two economic traits were affected by water stress de-
pended on the soybean genotype. High soil nitro- gen had adverse effects on seed oil concentration,
but increased the crude protein concentration of sesame seed from 21.5 to 25.0 Weiss, 1983.
White lupin has potential as a spring-sown grain legume in eastern Canada and the northern USA
Putnam et al., 1992. Seed yields of some cultivars have ranged from 2.5 to 4.0 t ha
− 1
Faluyi et al., 1997. Therefore, in eastern Canada there has been
considerable interest in lupin. The effects of agro- nomic practices on seed protein and oil of white
lupin cultivars have not been quantified under such short growing season conditions. The objective of
this research project was to determine appropriate management practices for production of better
quality sweet white lupin in eastern Canada by evaluating the effects of planting date, row spacing,
and soil type on the seed protein and oil levels of two lupin cultivars.
2. Materials and methods
2
.
1
. Experimental sites and procedures The study was conducted on a fertile sandy-loam
Typic, Melanic, Borunisol, Dystric, Eutrochrept and a well drained clay-loam soil Gleyed, Luvizol,
aquic Hapludalf at the E.A. Lods Agronomy Research Centre, McGill University, Ste. Anne de
Bellevue, Quebec, Canada, during the 1991 and 1992 crop growing seasons. In each year, two sites
that had not previously produced lupin were used for the experiments. Each site was fall-ploughed
and subjected to secondary harrowing prior to planting in the spring.
The experimental design was a 2 × 2 × 2 factorial arranged in a randomized complete block with four
replications; all factors were considered fixed ef- fects. The factors were cultivar Ultra and Pri-
morski, row width 20 and 40 cm and planting date early and late. In 1991, two lupin cultivars
were planted on May 1 sandy-loam and May 4 clay-loam for the early planting date while May
14 sandy-loam and May 15 clay-loam were the late planting dates. In 1992, May 1 and 12 were
early planting date and late planting dates, respec- tively, for both soil types. The two genotypes of
white lupin were selected because they are reported to have satisfactory seed yields under Canadian
conditions. The plot size was 9.6 m
2
4.0 × 2.4 m. The plots were seeded with 50 viable seeds m
− 2
. To ensure that nitrogen N was not limiting, the
seeds were inoculated with commercial Rhizobium lupini Urbana Laboratories, St. Joseph, Montana
before planting. As the fields had not previously grown lupin, the inoculation rate used was 454 g
50 kg
− 1
seed, double the recommended rate. Weed control was by hand and as necessary.
2
.
2
. Data collection A few days prior to harvest, ten plants were
randomly selected from the central region of each plot. After drying, seeds from each plant were
ground to pass a 1-mm screen with a Cyclone Mill Udy, Fort Collins, CO then dried to a constant
weight at 70°C.
Protein and oil concentrations in the white lupin seeds were determined by near infrared reflectance
NIR spectrometry using an Inframatic 8100 Per- tan Instruments, Reno, NV. The spectrophotome-
ter was calibrated with Lupinus albus samples of known protein and oil concentrations as deter-
mined by the Kjeldahl method protein using the Tecator Kjeltec system Tecator AB, Hoganas,
Sweden and the Soxlet method oil using the Tecator Soxtec system Tecator AB, Hoganas,
Sweden, respectively Zhang and Smith, 1994. Kjeldahl nitrogen values were multiplied by 6.25
to obtain crude protein values Panford et al., 1988. Seed protein content was calculated as the
amount of protein mg seed
− 1
protein concen- tration times individual seed weight and protein
yield in g plant
− 1
and kg ha
− 1
protein concen- tration times seed weight. Seed oil content and
yield were estimated as for protein.
2
.
3
. Statistical analyses All data were analyzed by analysis of variance
SAS Institute Inc., 1988 and all significant main effects and interactions were considered. Because
experimental errors were not homogenous over years, the data for each year are presented
separately. When analysis of variance indicated significant effects, a least significant difference
LSD
test was
used to
detect differences
between means Steel and Torrie, 1980. Because most
of the
variables investigated
in this
study were not different between soil types, the few main effects of soil type, and interactions
involving soil type, when they occurred, are de- scribed in the text rather than being shown in
tables.
3. Results
