Reduction in size of storage root of sugar beet due to heavy parasitism by Heterodera schachtii. After a fourth molt. Males are attracted to the females where fertilization occurs. An average of 200 eggs are produced by one female, a few of which are laid outside the body in the soil. At maturity, the female dies, and her body wall hardens and is transformed into a light brown to reddish brown cyst, completing the cycle.
Cysts are barely visible to the naked eye.
The cycle requires four to six weeks, depending on soil temperature. Three cycles have been reported to occur during the growing season in western Nebraska. Annual rate of decline of cysts in soil during rotation is estimated at 40-60 percent. Cysts may survive even Figure 5. Similar high populations occur in many areas of Nebraska supporting long-term sugar beet production.