Abstract
The effect of crop sequence on parasitism of second-stage juveniles (J2) of Heterodera glycines by Hirsutetta rhossiliensis was investigated. Data were collected from plots of a long-term crop rotation experiment established in 1982. Crop sequences included (i) continuous monoculture of corn and soybean; (ii) annual rotation of the two crops; and (iii) 1, 2, 3, 4, or 5 years of each crop following 5 years of the other crop. The nematode J2 density and percentage of J2 parasitized by the fungus were determined at planting, midseason, and end of season in 1997 and 1998. A significant effect of the crop sequence on parasitism of J2 was observed at midseason in both years and at end of season in 1998. In plots of first-year soybean following 5 years of corn, fungal parasitism increased from an undetectable level at planting to 2% and 4% of J2 parasitized by ends of season in 1997 and 1998, respectively. Fungal parasitism was similar in plots of second-through-fifth-year soybean after 5 years of corn and in plots of soybean monoculture. Parasitism of J2 in the soybean plots in annual rotation with corn increased from undetectable and 2% at planting to 6% and 23% at midseason in 1997 and 1998, respectively. The effect of crop sequence on the fungal parasitism of J2 may be attributed to a density-dependent relationship between the parasite and its host. Season also affected the fungal parasitism; percentage of J2 parasitized by the fungus was the highest at midseason and the lowest at planting.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 437-444 |
| Number of pages | 8 |
| Journal | Journal of Nematology |
| Volume | 31 |
| Issue number | 4 |
| State | Published - Dec 1999 |
Keywords
- Biological control
- Corn
- Crop rotation
- Crop sequence
- Glycine max
- Heterodera glycines
- Hirsutella rhossiliensis
- Nematode
- Nematophagous fungus
- Soybean
- Soybean cyst nematode
- Zea mays
