Table 1.
Effect of Solanum sisymbriifolium on Globodera pallida egg density and viability and on subsequent reproduction on potato in 2015.
| Remaining eggs/cysts | Egg viability (%) | Progeny cyst (no./kg soil) | Encysted eggs (eggs/g soil) | Pf a (eggs/g soil) | Pf/Pi b (eggs/g soil) | |
|---|---|---|---|---|---|---|
| Treatment | After 10 wkc | Reproduction on potatod | ||||
| Fallow | 299e | 57.0 | 36 | 196 | 6.9 | 2.8 |
| S. sisymbriifolium | 230 | 58.1 | 4 | 10 | 0.02 | 0.01 |
| P-valuef | 0.10 | 0.92 | 0.0001 | 0.0001 | 0.0001 | 0.0001 |
1 Note: a Pf=final egg population density; b Pf/Pi=final egg population density/initial egg population density (Pi ); ceggs remaining in cysts initially used for soil infestation were measured 10 wk after infesting into bare soil or S. sisymbriifolium. Soil was infested with a Pi of 2.5 encysted eggs/g soil; dreproduction was assessed after a second 16-wk cycle where all treatments were planted to potato; evalues are the mean of six replicates; f P-value was determined by analysis of variance.
Table 2.
Effect of Solanum sisymbriifolium on Globodera pallida egg density and viability and on subsequent reproduction on potato in 2016.
| Remaining eggs/cysts | Egg viability (%) | Progeny cyst (no./kg soil) | Encysted eggs (eggs/g soil) | Pf a (eggs/g soil) | Pf/Pi b (eggs/g soil) | |
|---|---|---|---|---|---|---|
| Treatment | After 12 wkc | Reproduction on potatod | ||||
| Fallow | 162e | 71.4 | 20 | 187 | 3.5 | 1.4 |
| S. sisymbriifolium | 81 | 66.4 | 0 | 0 | 0 | 0 |
| P-valuef | 0.002 | 0.19 | 0.0006 | 0.0001 | 0.0001 | 0.0001 |
1 Note: a Pf = final egg population density; b Pf/Pi = final egg population density/initial egg population density (Pi); ceggs remaining in cysts initially used for soil infestation were measured 12 wk after infesting into bare soil or S. sisymbriifolium. Soil was infested with a Pi of 2.5 encysted eggs/g soil; dreproduction was assessed after a second 16-wk cycle where all treatments were planted to potato; evalues are the mean of six replicates; f P-value was determined by analysis of variance.
Table 3.
Effect of treatment (bare ground or Solanum sisymbriifolium) and termination date after treatment establishment on Globodera ellingtonae egg densities in soil at Powell Butte, Oregon in 2014 and 2015.
| Termination date (weeks after S. sisymbriifolium planting)a | ||||
|---|---|---|---|---|
| Treatment | 3 | 6 | 9 | 12 |
| G. ellingtonae eggs/cystb | ||||
| 2014 | ||||
| S. sisymbriifolium | 196 ac | 98 b | 69 b | ntd |
| Fallow | 209 a | 195 a | 173 a | nt |
| 2015 | ||||
| S. sisymbriifolium | nt | 218 b | 108 c | 58 d |
| Fallow | nt | 271 a | 261 a | 179 b |
1 Note: aTreatments were established on May 19, 2014 and June 8, 2015; binitial density in 2014 was 30 ± 734 eggs/cyst with approximately 50 cysts, and in 2015 was 31126 with approximately 75 cysts; cvalues are the means of six observations. All values in the same year followed by the same letter are not significantly different according to Dunnett’s adjustment for multiplicity (P ≤ 0.05); dnt = not tested.
Table 4.
Influence of nematode-susceptible or resistant tobacco, Solanum ptychanthum, S. sisymbriifolium, fallow on Globodera tabacum population change over one season in field microplots.
| 2015 | 2016 | |||||
|---|---|---|---|---|---|---|
| Treatment | Pi a | Pf a | Pf/Pi a | Pi | Pf | Pf/Pi |
| Susceptible tobacco | 90.6b | 193.6 | 2.9 ac | 64.0 | 173.8 | 2.8 a |
| Resistant tobacco | 103.8 | 36.4 | 0.4 b | 82.6 | 29.7 | 0.3 b |
| S. ptychanthum | ntd | nt | nt | 77.3 | 335.1 | 6.6 a |
| S. sisymbriifolium | 91.1 | 10.6 | 0.1 c | 75.6 | 9.3 | 0.2 c |
| Fallow | nt | nt | nt | 86.4 | 43.4 | 0.56 b |
| P-value | 0.89 | 0.0001 | 0.0001 | 0.86 | 0.0001 | 0.0001 |
1 Note: aPf/Pi = final egg population density (Pf)/initial egg population density (Pi). Data were log transformed and differences between final and initial populations analyzed by analysis of variance. Means were separated by Fishers LSD multiple comparison test; bvalues are the means of 20 replicate plots in 2015 and 12 or 13 replicates in 2016. Values followed by the same letter are not significantly different according to Fisher’s LSD multiple comparison tests (P ≤ 0.05); cnumbers within columns followed by the same letter are not significantly different; dnt = not tested.