Effect of Crop Rotation and Cultivar Resistance on Seed Yield and the Soybean Cyst Nematode in Full‐Season and Double‐Cropped Soybean

Abstract

Soybean cyst nematode (Heterodera glycines Ichinohe) can cause considerable damage to soybean [Glycine max (L.) Merr.], especially in western USA growing areas that are newly infested. The objective of this study was to find cultural practices that reduce cyst nematode effect on soybean in this region. Four management systems, one having continuous susceptible soybean, a second consisting of a 3‐yr rotation with 2 yr of a nonhost crop followed by susceptible soybean, and two 4‐yr rotations alternating a susceptible and resistant cultivar with non‐host crops, were investigated at nematode‐infested and noninfested locations. One 4‐yr rotation had full‐season soybean while the other had double‐crop soybean. Data included soybean seed yield, yield components, and cyst nematode egg density. Grain yields of full‐season, SCN‐susceptible ‘Stafford’ were similar in all rotations at each location. Nonhost crops reduced nematode densities from 4000 eggs 100 cm−3 in continuously cropped SCN‐susceptible plots to 1000 and 500 eggs 100 cm−3 in 3‐ and 4‐yr rotations, respectively. However, nematode numbers rapidly increased to more than 5000 eggs 100 cm−3 by seasons end when susceptible soybean was grown. The SCN‐susceptible cultivar produced 33% less grain and pods than did the SCN‐resistant cultivar, Manokin, at the infested location while the cultivars yielded similarly at the noninfested site. Full‐season and double‐cropped soybean reacted similarly to SCN. Crop rotation reduced cyst nematode numbers, but this benefit did not reduce yield losses on subsequent SCN‐susceptible soybean as numbers rapidly climbed to damaging levels.

Effect of Host Resistance to Fusarium virguliforme and Heterodera glycines on Sudden Death Syndrome Disease Severity and Soybean Yield

“…Soybean yields were not directly correlated with H. glycines soil population densities in the present study ( Table 5). This observation conflicts with a large body of evidence for SCN involvement in soybean yield suppression (1,4,14,38), but can be explained by the combination of low H. glycines population densities in all study environments and the low to moderate level of SCN resistance exhibited by the soybean cultivars. It is clear that these results do not match expectations for situations where damaging population levels of the nematode are present, or where cultivars with high levels of resistance are available.…”

Rotation Crop Evaluation for Management of the Soybean Cyst Nematode in Minnesota

“…A number of studies have reported on the effect of rotation crops on SCN populations and soybean yields (Ross, 1962; Weaver et al, 1988; Edwards et al, 1988; Rodriguez‐Kabana et al, 1991; Weaver et al, 1993; Koenning et al, 1993; Hershman and Bachi, 1995; Koenning et al, 1995; Howard et al, 1998; Long and Todd, 2001; Chen et al, 2001c; Noel and Wax, 2003). In these studies, however, only one or a few nonhost (mainly corn [ Zea mays L.], wheat [ Triticum aestivum L.], and sorghum [ Sorghum bicolor (L.) Moench] or poor‐host crops were compared with soybean.…”

How Eco-Efficient Are Low-Input Cropping Systems in Western Europe, and What Can Be Done to Improve Their Eco-Efficiency?

“…Numerous experiments have shown that soybean yields are increased when this crop is grown in rotation with non-leguminous crops [62][63][64][65][66]. Changing from soybean to another crop breaks the lifecycle of soybean cyst nematodes (SCN's).…”