title: Tolerance Limit of the Sugarbeet to Heterodera schachtii.
abstract: Field and greenhouse experiments showed that yield losses of sugarbeet, Beta vulgaris, did not occur in soil infested with fewer than eight Heterodera schachtii eggs/g soil. However, larger population densities greatly reduced sugarbeet yield. In the field experiment, the yield in microplots inoculated with more than 64 eggs/g soil was less than 20% of yields in uninoculated microplots. Nevertheless, tolerance limits of 4 and 1.8 eggs/g soil, in greenhouse and field microplots, respectively, were derived by fitting the data with the equation y =m + (l - m)z(P-T). Maximum rates of multiplication of 55 and more than 300, and equilibrium densities of 340 and 130 eggs/g soil, were estimated in greenhouse and field microplot tests, respectively.
authors.forename: N
authors.initials: N
authors.lastname: Greco
authors.forename: A
authors.initials: A
authors.lastname: Brandonisio
authors.forename: G
authors.initials: G
authors.lastname: De Marinis