Cropping history, field size, and nematodes present other than sugarbeet cyst nematode for the 10 San Joaquin Valley fields (A to J) sampled in the study_
| Years | Field Location | |||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| A | B | C | D | E | F | G | H | I | J | |
| −1a | Cabbage | Bok choy | Wheat | Sugarbeet | Sugarbeet | Sugarbeet | Sugarbeet | Sugarbeet | Sugarbeet | |
| 0 | Cabbage | Bok choy | Sugarbeet | Bean | Bean | Tomato | Tomato | Bean | Sugarbeet | Tomato |
| 1 | Tomato | Beans | Beans | Wheat | Wheat | Wheat | Wheat | Wheat | Corn | Corn |
| 2 | Cabbage | Cabbage | Tomato | Fallow | Tomato | Tomato | Tomato | Tomato | Fallow | Corn |
| 3 | Wheat | Wheat | Wheat | Bean | Tomato | Tomato | Tomato | Tomato | Sugarbeet | Corn |
| 4 | Tomato | Tomato | Tomato | Wheat | Wheat | Wheat | Wheat | Wheat | Fallow | |
| 5 | Wheat | Tomato | Tomato | Corn | Tomato | Tomato | Tomato | Tomato | Fallow | |
| 6 | Tomato | Beans | Wheat | Bean | Wheat | Wheat | Wheat | Wheat | ||
| Size of field (ha) | 32 | 3 | 32 | 32 | 8 | 8 | 8 | 8 | 32 | 32 |
| Years out of sugarbeet prior to −1 | Unknown | 8 | 7 | Unknown | 4 | 4 | 8 | 8 | 4 | 20 |
| Other plant-parasitic nematodes | none detected | none detected | Pratylenchus sp. | Tylenchorhynchus sp. | Meloidogyne sp., Pratylenchus sp., Xiphinema sp. | Meloidogyne sp., Pratylenchus sp., Xiphinema sp. | none detected | none detected | none detected | Helicotylenchus sp. |
Physical characteristics of soils in fields sampled in the study_
| Percent | ||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Field location | Soil type | Sand | Silt | Clay | OMa | SP | pH | EC millimhos/cm | Ca milliequivalents/l | Mg milliequivalents/l | Na milliequivalents/l | SAR |
| A | silty clay loam | 15 | 48 | 37 | 2.0 | 46 | 7.0 | 0.81 | 3.1 | 2.9 | 2.1 | 1 |
| B | silty clay | 11 | 44 | 45 | 2.1 | 53 | 7.2 | 0.62 | 2.5 | 1.9 | 1.8 | 1 |
| C | silty clay | 12 | 47 | 41 | 2.4 | 55 | 7.3 | 0.61 | 2.4 | 2.1 | 1.6 | 1 |
| D | silty clay | 14 | 45 | 41 | 1.8 | 50 | 6.9 | 0.80 | 3.4 | 2.3 | 2.3 | 1 |
| E | silty clay | 12 | 44 | 44 | 1.8 | 48 | 7.0 | 0.67 | 3.0 | 1.8 | 1.9 | 1 |
| F | silty clay | 15 | 44 | 41 | 1.5 | 46 | 7.1 | 0.69 | 3.1 | 2.3 | 1.5 | 1 |
| G | silty clay loam | 14 | 47 | 39 | 1.5 | 45 | 6.2 | 0.59 | 2.0 | 1.8 | 2.1 | 2 |
| H | silty clay | 13 | 42 | 45 | 1.4 | 44 | 6.1 | 0.65 | 2.3 | 2.1 | 2.1 | 11 |
| I | loam | 35 | 44 | 21 | 6.2 | 47 | 7.4 | 0.73 | 3.7 | 2.3 | 1.3 | 1 |
| J | loam | 37 | 37 | 25 | 5.2 | 44 | 7.3 | 0.58 | 2.9 | 1.7 | 1.2 | 1 |
Recovery of Heterodera schachtii eggs and cysts from 10 San Joaquin Valley fields for multiple years after initiation of sampling_
| Field Location | Number/gram | ||||||
|---|---|---|---|---|---|---|---|
| Years | Eggs | Cysts | Eggs/cyst | ||||
| A | 0.0 | 4.35 | ba | 0.267 | c | 10.9 | c |
| 0.3 | 1.88 | a | 0.114 | abc | 7.6 | bc | |
| 1.8 | 2.07 | a | 0.134 | abc | 8.7 | bc | |
| 2.8 | 0.74 | a | 0.034 | a | 5.3 | ab | |
| 3.8 | 1.80 | a | 0.223 | bc | 3.5 | ab | |
| 6.3 | 0.41 | a | 0.067 | ab | 2.1 | a | |
| B | 0.0 | 0.17 | a | 0.011 | a | 1.2 | a |
| 0.5 | 0.02 | a | 0.001 | a | 0.2 | a | |
| 1.8 | 0.01 | a | 0.001 | a | 0.1 | a | |
| 2.8 | 0.03 | a | 0.002 | a | 0.3 | a | |
| 3.8 | 2.94 | b | 0.187 | b | 5.4 | b | |
| 5.1 | 0.21 | a | 0.038 | a | 1.4 | a | |
| C | 0.0 | 0.21 | a | 0.029 | a | 1.4 | a |
| 1.8 | 1.78 | b | 0.150 | bc | 7.0 | b | |
| 2.8 | 0.65 | a | 0.052 | a | 4.2 | a | |
| 3.8 | 1.27 | ab | 0.168 | c | 3.4 | a | |
| 5.1 | 0.47 | a | 0.072 | ab | 2.0 | a | |
| 6.3 | 0.51 | a | 0.097 | abc | 2.4 | a | |
| D | 0.0 | 1.28 | ab | 0.036 | a | 6.3 | bc |
| 0.3 | 0.59 | ab | 0.066 | a | 2.2 | ab | |
| 1.8 | 1.44 | b | 0.072 | a | 7.0 | bc | |
| 2.8 | 1.03 | ab | 0.038 | a | 7.9 | c | |
| 4.4 | 0.31 | ab | 0.019 | a | 2.5 | ab | |
| 6.3 | 0.13 | a | 0.026 | a | 0.9 | a | |
| E | 0.0 | 1.08 | c | 0.066 | c | 6.1 | d |
| 0.3 | 0.84 | bc | 0.044 | bc | 5.2 | bcd | |
| 1.8 | 0.72 | abc | 0.025 | ab | 5.7 | cd | |
| 2.8 | 0.23 | ab | 0.019 | ab | 2.0 | abc | |
| 4.4 | 0.12 | a | 0.003 | a | 1.1 | a | |
| 5.1 | 0.31 | ab | 0.013 | ab | 2.7 | abcd | |
| 6.3 | 0.21 | ab | 0.032 | ab | 1.3 | ab | |
| F | 0.0 | 1.60 | b | 0.089 | ab | 6.1 | b |
| 0.3 | 0.90 | ab | 0.127 | b | 3.9 | ab | |
| 1.8 | 1.14 | ab | 0.059 | ab | 5.6 | ab | |
| 2.8 | 0.32 | ab | 0.049 | ab | 1.9 | ab | |
| 4.4 | 0.10 | a | 0.018 | a | 0.7 | a | |
| 5.1 | 0.35 | ab | 0.061 | ab | 2.0 | ab | |
| 6.3 | 0.06 | a | 0.019 | a | 0.4 | a | |
| G | 0.0 | 0.04 | a | 0.002 | ab | 0.3 | a |
| 0.3 | 0.15 | a | 0.009 | bc | 1.2 | a | |
| 1.8 | 0.00 | a | 0.001 | a | 0.0 | a | |
| 2.8 | 0.13 | a | 0.005 | abc | 1.0 | a | |
| 4.4 | 0.03 | a | 0.001 | ab | 0.3 | a | |
| 5.1 | 0.09 | a | 0.013 | c | 0.8 | a | |
| 6.3 | 0.00 | a | 0.000 | a | 0.0 | a | |
| H | 0.0 | 0.00 | a | 0.006 | bc | 0.0 | a |
| 0.3 | 0.67 | b | 0.006 | bc | 6.4 | b | |
| 2.0 | 0.18 | a | 0.001 | a | 1.8 | a | |
| 2.8 | 0.01 | a | 0.010 | c | 0.1 | a | |
| 4.4 | 0.00 | a | 0.001 | ab | 0.0 | a | |
| 5.1 | 0.12 | a | 0.003 | ab | 1.2 | a | |
| 6.3 | 0.00 | a | 0.001 | ab | 0.0 | a | |
| I | 0.0 | 9.59 | c | 0.204 | a | 25.0 | b |
| 1.8 | 7.00 | bc | 0.230 | a | 20.8 | b | |
| 2.3 | 3.99 | ab | 0.121 | a | 16.5 | b | |
| 3.3 | 1.72 | a | 0.155 | a | 4.0 | a | |
| 4.6 | 1.17 | a | 0.151 | a | 4.7 | a | |
| J | 0.0 | 1.51 | b | 0.188 | b | 5.1 | a |
| 0.3 | 1.38 | b | 0.172 | b | 5.2 | a | |
| 2.8 | 0.40 | a | 0.042 | a | 3.0 | a | |
| 3.8 | 0.32 | a | 0.074 | a | 1.9 | a | |