Study of the date and method of sowing as indirect weed control methods for organic soybean production

Georgi Georgiev

Abstract: Data from two-factor field experiments carry out in the 2014-2017 period in Soybean Experimental Station – Pavlikeni wеre used in the study. The experiments were carried out with two Bulgarian soybean varieties: Avigeya – early variety, and Richy - middle early variety. Three sowing dates (early, optimal and late) and three sowing methods (respectively row spacing and sowing density) were studied - wide row spacing in 45 cm, two-row tape in 15/40 cm and narrow row spacing in 25 cm. Dependencies and trends have been identified with the duration
of important growth periods („germination – shading” and „shading – harvesting”) indirectly affecting the weed control. The soybean yields are also analyzed depending on the studied factors and variants. The summarized four-year results show that the variants with late date of sowing + narrow row spacing in 25 cm, can be used as effective indirect weed control methods, for organic soybean production.

Keywords: organic production; row spacing; sowing date; soybean

Date published: 2018-03-12