Leguminous Vegetable Cultivation and Seed Production S ...

m
366 GREEN MANURE IN RICE FARMING
Hot water pregermination stress includes soaking seeds for 70 s in 75 'C water
and rinsing in tap water prior to determining germination or emergence (Kueneman
( g 82).
Kueocooan(] q 83 ) evaluated the F I seeds of reciprocal crosses between soybean
genotypes with good and poor seed longevity using the accelerated aging method.
He found significant reciprocal differences, and suggested the possible influence of
the maternal plant genome on seed longevity. The pooled F 2 variances were larger
than pooled parental variances, which indicated the influence of the genotypes.
Differences between reciprocals of the F 2
seed, although relatively small compared
to those between F, reciprocals, were significant, indicating that cytoplasmic gene
action for seed longevity may also be involved, but its effects are probably small.
Because of the influence of the maternal plant, expression of segregation is delayed
one geoeratioo(Koeoeouau 1983). `
Dassou and Kueneman (1984 ) subjected physiologically mature pods to a
weathering technique in an incubator a{30 °C and 90-95 % relative humidity ( RH )
for 10 d. They identified several genotypes resistant to both seed weathering and
deterioration in storage ( Table 3 ) . Paschal and Ellis ( 1978 ) reported that genotypes
PI 205912, P1 205907, [»[ 341249, PI 279088, and {/1 219653 could be used for
breeding soybean with resistance to field weathering and to seed deterioration in
storage.
An early-maturing variety can be used to avoid weathering damage. In Taiwan,
for example, spring soybean is planted in February-March and harvested in roid-
May.Hovvovez `
early maturity is not a dependable alternative. In some years, rains
may come early and spoil the crop.
Manipulating the cropping pattern also can be used to avoid field weathering in
the rainy season. In Pakistan, soybean for seed is planted July-August and harvested
October-November (Beg 1987). In East Java, Indonesia, lowland and upland
soybeans are planted year-round. Seed for the lowland rainy season and dry season
Table 3. Genotypes resistant to seed weathering and to deterioration in storage.
Genotype
Origin
1 00'noed Seed
wt (g) color
Hard After incubator After ambient
seed a weathering storageb
I NDO 153 Indonesia
IPA DO 131 Indonesia
I P4 DO 243P Indonesia
1 WOD226 Indonesia
104 DO 255 Indonesia
INDO 173A Indonesia
Fort Lamy USA
Lee A
USA
Biloxi 3 China
AVRDC 8457 Taiwan
9.7 Black 36.0 54.2 87
10.2 Black 24.6 35.4 92
8.9 Black 17.2 42.9 90
9.3 Black 27.2 46.2 80
10.1 Black 30.6 32.6 91
1 0.8 Black 52.6 32.9 81
10.5 Black 46.6 56.2 80
9.0 Black 62.0 58.5 88
10.5 Black 37.2 50.4 71
6.1 Black 64.0 58.7 77
Source: O0000uond Kueneman 1984.
Nonimbibino seed after 1 h soaking in water.
humidity.
Stored forO mo at 25 0 C and 50 to 95% relative