Companion Crops for Weed Control in Soybeans¹

Spring-Interseeded Winter Rye Seeding Rates Influence Weed Control and Organic Soybean Yield

“…As winter rye seeding rate increased, soybean fresh weight (Table 2), and density (Table 3) decreased compared to the weed-free control. Our finding of a reduction in soybean growth under low precipitation conditions in 2002 was consistent with reports by other researchers [6,11] and likely reflects competition between rye and soybean for available moisture.…”

“…Weed control using companion crops such as winter rye seeded and narrowrow soybean was described in the 1950s [11]. Winter rye was preferred as a companion crop over wheat (Triticum aestivum L.).…”

“…However, winter rye residue cannot provide full-season weed suppression [16,17,21,22]. When used in an organic production system, winter rye has suppressed weeds through physical interference as a living mulch, but this system may also decrease crop grain yields [6,11,23]. Management of rye 2 International Journal of Agronomy using cultivation was necessary to minimize yield reductions, particularly in dry years, because no alternative methods exist to control rye in organic soybean.…”

“…Management of rye 2 International Journal of Agronomy using cultivation was necessary to minimize yield reductions, particularly in dry years, because no alternative methods exist to control rye in organic soybean. Winter rye requires a vernalization period before jointing and flowering, and it commonly dies under summer stress [11,21]. Interseeding winter rye in spring may promote a synergistic relationship with soybean, while restricting rye to vegetative growth.…”

Economic Losses Caused by Weed Competition in Manitoba Grain Fields. I. Weed Species, Their Relative Abundance and Their Effect on Crop Yields

“…Out of a total loss of $4og,ooo,ooo, $249,000,000 were attributed to reduced crop yields. His estirnate on losses caused bv weed comDetition was based on 15 per cent of total field crop production. Wood 121 placed the losses caused by weeds in the Prairie Provinces of Canada at $255,000,000 of which $166,000,000 was attributed to weed competition in the major crops grown in the area.…”