**3. Results**

276 Soybean Physiology and Biochemistry

m-2, 11.25 and 30cm plant spacing in wide and narrow row-spacing, respectively) and dense (22.2 plants m-2, 5.6cm and 15cm in wide and narrow row-spacing, respectively) planting density. Each plots size was 57.6 m2 (3.2×18.0m)with no replication. A basal fertilizar was applied at the rate of 2.1g N, 4.4g P and 10.0g K. Herbicide was applied to the soil surface to avoid weed emergence. The plants were thinned to a plant per hill when primary leaves were fully expanded. In wide row plots, soil molding was conducted by a rotary cultivator. The crop was irrigated with a water-spraying vinyl hose placed on every other row.

Thirty plants were harvested from each plots, and ten standard plants were selected to examine the node number, main stem length, stem diameter, stem weight, and seed/stem weight ratio. Pods were distinguished on the position, main stem/branches and raceme order (Fig. 1.), and seeds were depodded manually, then weighed to record the data on

The raceme orders were defined as follows (Torigoe et al. 1982). The terminal racemes appeared at the top of the stems, and first order racemes differentiate from the axil just above the petiole on the stem. The secondary racemes differentiate from both sides of the first order raceme and tertiary racemes differentiate from the sides of the secondary racemes. Racemes differentiating from both sides of the branch were classified as secondary racemes. The terminal and first order racemes, and those over secondary raceme will be collectively called basal raceme and lateral raceme, respectively. Some lateral racemes had compound leaves. The lodging score was recorded every week by measuring the angle of the main stem, and ranked 0 (erect), 1 (inclined 15 degrees), 2 (inclined 45 degrees), 3 (inclined 75 degrees) and 4 (inclined horizontally), then the average score was obtained.

Recommended pesticides were applied for the control of insects and diseases.

Fig. 1. Classification of raceme order in determinate type of soybean.

Five plants (three replication for each plots) were sampled and three (nine plants for each plots) were separated into leaves, petioles, stems and pods on each main stem and branch, then measured the leaf area of a standard plant (AAM-8, Hayashidenko). Samples were air-

**2.3 Dry matter production and canopy structure** 

**2.2 Growth and yield observation** 

yield and yield components.
