Table 1:
Average n = 6 reproduction factor (RF) final population/initial population of Meloidogyne marylandi on 28 crop cultivars grown in 1-liter pots 6 weeks after inoculation with 3,500 M. marylandi eggs per pot.
| Species | Common name | Cultivar | Reproduction factor1 |
|---|---|---|---|
| Hordeum vulgare | Barley | Morex | 38.57 ± 12.65 a |
| Avena sativa | Oat | California Red | 35.12 ± 13.79 a |
| Zea mays | Sweet Corn | Silver Queen | 16.16 ± 6.25 a |
| Triticum aestivum | Wheat | Ojo Rojo | 12.19 ± 2.33 a |
| Agrostis stolonifera | Creeping Bentgrass | Penn A-4 | 6.46 ± 4.12 bcd |
| Cynodon dactylon | Bermudagrass | Southern Starr | 4.97 ± 2.02 ab |
| Cynodon dactylon | Bermudagrass | Numex Sahara | 4.61 ± 1.11 ab |
| Lolium perenne | Perennial Ryegrass | Zoom | 4.09 ± 1.28 ab |
| Festuca ovina glauca | Blue Fescue | Elijah Blue | 3.77 ± 0.87 ab |
| Poa annua | Annual Bluegrass | Two Putt | 3.11 ± 0.79 abc |
| Cynodon dactylon | Bermudagrass | Sundevil II | 2.00 ± 0.79 bcde |
| Festuca rubra | Red Fescue | Commutata J5 | 1.71 ± 0.61 bcdef |
| Poa pratensis | Kentucky Bluegrass | 4-Season | 0.71 ± 0.27 efg |
| Festuca arundinacea | Tall Fescue | Watchdog | 0.51 ± 0.21 fg |
| Allium porrum | Leek | American Flag | 0.23 ± 0.10 defg |
| Agrostis capillaris | Colonial Bentgrass | Jorvik | 0.11 ± 0.04 efg |
| Allium schoenoprasum | Chives | Garlic | 0.08 ± 0.02 fg |
| Allium cepa | Onion | Yellow Granex | 0.06 ± 0.04 gh |
| Arachis hypogaea | Peanut | Florrunner | 0.00 ± 0.00 h |
| Capsicum annuum | Pepper | California Wonder | 0.00 ± 0.00 h |
| Secale cereale | Rye | Merced | 0.00 ± 0.00 h |
| Beta vulgaris | Sugarbeet | 5 GK 1122 | 0.00 ± 0.00 h |
| Citrullus lanatus | Watermelon | Charleston Grey | 0.00 ± 0.00 h |
| Brassica oleracea var. italica | Broccoli | Liberty | 0.00 ± 0.00 h |
| Brassica oleracea | Cabbage | Copenhagen Market | 0.00 ± 0.00 h |
| Cucumis melo | Cantaloupe | Durango | 0.00 ± 0.00 h |
| Gossypium hirsutum | Cotton | GC 510 | 0.00 ± 0.00 h |
| Cucumis sativus | Cucumber | Imanol | 0.00 ± 0.00 h |
| P-value crop cultivar effect: < 0.0001 | |||
1 Values shown are the mean of 6 replicates n = 6±SE. Statistical analysis was done using the Kruskall-Wallis test to test the significance of the crop cultivar on Log10[eggs per root system +1]-transformed data. Values in a column followed by different letters are significantly different P ≤ 0.05 according to the Bonferroni test.
Figure 1:
Example of two perineal patterns of a Meloidogyne marylandi population isolated from creeping bentgrass in Indian Wells, California.
Figure 2:
Average (n = 3) egg production [Log10(eggs per root system) + 1] of Meloidogyne marylandi on 28 crop cultivars in two replicated experiments, 6 weeks after inoculation with 3,500 eggs.
Table 2:
Effect of soil temperature (°C) on number of days to complete the life cycle of a M. marylandi population.
| Soil temperature | Experiment | |||
|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |
| 17 | 55 | 59 | ||
| 20 | 41 | 41 | ||
| 25 | 29 | 30 | 30 | |
| 27 | 27 | 26 | ||
| 29 | 23 | 24 | ||
| 30 | 24 | 25 | ||
| 31 | 24 | 32 | ||
| 33 | 25 | |||
| 35 | 29 | 29 | ||
Table 3:
Average n=5 reproduction factor RF (number of J2 recovered/number of J2 inoculated) of a M. marylandi population during the first five days after life cycle completion at different soil temperatures (°C).
| Soil temperature | Experiment | |||
|---|---|---|---|---|
| 1 | 2 | 3 | 4 | |
| 17 | 0.06 | 0.13 | ||
| 20 | 0.22 | 0.93 | ||
| 25 | 2.06 | 0.93 | 5.20 | |
| 27 | 14.12 | 6.85 | ||
| 29 | 2.71 | 3.00 | ||
| 30 | 1.66 | 2.94 | ||
| 31 | 1.60 | 0.11 | ||
| 33 | 0.28 | |||
| 35 | 0.04 | 0.01 | ||
Figure 3:
Effect of soil temperature on the reproductive rate R (days-1) of Meloidogyne marylandi in four experiments. Line represents regression analysis : R = 0.0020 × Ts-0.0168 for Ts = 17 – 29 °C, according to R = 1/S × Ts - Tb/S, with S = required heat sum (degree-days), Ts = soil temperature (°C), and Tb = base temperature (°C) for reproduction. Correlation coefficient R2 = 0.998.
Figure 4:
Average (n = 12) total fresh weight of creeping bentgrass (Agrostis stolonifera) cuttings over a 180-day period under a range of Meloidogyne marylandi second-stage juvenile inoculum densities. Bentgrass was grown in 164 cm3 plastic cones in a greenhouse and cut every two weeks.