Ana Ulafić, Ivana Varga, Miro Stošić, Dario Iljkić and Manda Antunović
University of Josip Juraj Strossmayer in Osijek, Faculty of Agrobiotechnical Sciences Osijek, 31 000 Osijek, Republic of Croatia
Ulafić, A., Varga, I., Stošić, M., Iljkić, D. & Antunović, M. (2020). Analysis of soybean growth in regard to different row-spacing. Bulg. J. Agric. Sci., 26 (3), 533–539
The aim of this study was to analyze soybean plant development during 2018 vegetation and finally seed yield regard to different row-spacing:12.5, 25, 50 and 70 cm. Soybean genotype Ika (0 – 1 maturity group) was sown on 26 April 2018. At the beginning of each month (June-September), therefore the plant sampling was done at V3, R3, R6 and R7 growth phase. In each sampling date 20 plants from every row-spacing were taken in order to determine plant height (cm plant-1), fresh plant mass (g plant-1) and dry matter weight (g plant-1). Final harvest was done on 11th October 2018. Regression analysis showed that in September (R7 growth phase) increasing the stem height by 1 cm, the fresh mass of the plant increased by 1.76 g to the plant-1 and the dry matter by 0.22 g plant-1 Different row-spacing had very significant influence (p < 0.01) on stem elongation through the vegetation period. The largest increase in stem, fresh matter and dry matter of soybean plants was determined from 1st July to 1st August, when the average stem increment was 48.8 cm per plant, or 1.6 cm plant-1 day-1. On average, the highest fresh and dry mattter acuumulation was determined in the period from 1st July to 1st August (R3 to R6) and it account total 90.73 g plant-1 and 26.60 g plant-1, respectively. In R7 growth phase at the beginning of September, the highest soybean stem was at 50 cm row-spacing, when it was on average 119.7 cm in plant-1, or 13.9% more than the average of the experiment (103.1 cm). The highest positive and significant correlation was found at 1st July between soybean fresh mater and dry matter (r = 0.964***) and on the opposite the highest and very significant negative corelation was determined at 1st June between plant height and seed yield per plant (r = – 0.712***). There were vary significant inflence (p < 0.05) of row-spacing on seed yield. The highest soybean yield per plant was found in row-spacing 70 cm (19.79 g plant-1) and the lowest in row-spacing of 12.5 cm (8.65 g plant-1). Generally, the highest seed yield was determined at 25 cm row-spacing where it was on average 1.90 t ha-1.