SOIL DEGREE DAY ACCUMULATION FOR NEMATODE CONTROL 
RUSSET NORKOTAH, SLV RESEARCH CENTER - 2013
For root-knot nematode control, Vydate applications should begin at 800 Degree-days (DD5Celcius)
or 1,440 DD41Fahrenheit.  To estimate that date, add the number of "Total  DD" on the day you planted
to 800 (or 1,440).  Where that value occurs in the "Total DD" column estimates the date on
which 800 DD5C or 1,440 DD41F will occur in that field.
Contacts for questions: Russ Ingham 541-737-5255
Rob Davidson 719-754-3494 ext. 15
Andrew Houser 719-754-3494 ext. 26
This information can also be found on the SLV Research Center Website:  
http://www.colostate.edu/Depts/SLVRC/disease/nematode.htm
These data were updated Monday, June 17, 2013
Data after that date are estimated using average temperature for the previous 7 days.
The last date when the Degree Days were updated is in bold.
Avg.  HISTORICAL
GROWING AVE SOIL DAILY TOTAL AVE SOIL DAILY TOTAL 2002- TOTAL DD41F
MONTH DAY DAYS TEMP - C DD5C DD5C TEMP F DD41F DD41F   2012 2011 2010 2009 2008 2007 2006 2005 2004
1-May 1 1 14.6 9.6 9.6 58.3 17.3 17.3   10.3 10.1 9.9 16.0 15.2 17.11 15 10 10  
2-May 2 2 12.7 7.7 17.3 54.8 13.8 31.1   21.3 16.0 19.6 32.4 26.0 33.98 31 18 18  
3-May 3 3 12.8 7.8 25.1 55.0 14.0 45.1   33.2 24.4 31.8 46.5 37.5 50.97 49 26 26  
4-May 4 4 13.6 8.6 33.7 56.6 15.6 60.7   46.9 37.0 47.5 61.6 51.8 67.1 68 37 37  
5-May 5 5 13.7 8.7 42.4 56.6 15.6 76.3   61.3 51.7 65.0 78.1 68.4 81.84 87 48 48  
6-May 6 6 13.0 8.0 50.4 55.4 14.4 90.7   75.8 68.5 83.1 96.3 85.7 93.68 105 60 60  
7-May 7 7 12.0 7.0 57.4 53.6 12.6 103.3   91.4 87.5 102.1 116.4 103.8 107.2 123 72 72  
8-May 8 8 12.4 7.4 64.8 54.4 13.4 116.7   107.6 106.9 122.3 138.0 121.3 122.9 142 84 84  
9-May 9 9 10.6 5.6 70.4 51.1 10.1 126.8   124.3 126.2 144.0 159.8 137.4 140.2 160 98 98  
10-May 10 10 11.0 6.0 76.4 51.8 10.8 137.6   141.2 144.0 165.9 182.1 154.2 159.5 176 115 115  
11-May 11 11 12.9 7.9 84.3 55.1 14.1 151.7   158.7 161.6 185.7 205.2 170.9 180.6 193 131 131  
12-May 12 12 14.5 9.5 93.8 58.1 17.1 168.8   176.6 176.8 205.4 228.7 189.6 202.8 212 146 146  
13-May 13 13 16.1 11.1 104.9 61.0 20.0 188.8   195.2 194.6 224.8 252.6 207.8 224.9 233 162 162  
14-May 14 14 16.1 11.1 116.0 61.0 20.0 208.9   214.1 213.7 244.6 276.9 223.7 246.6 254 179 179  
15-May 15 15 16.1 11.1 127.1 60.9 19.9 228.8   233.5 233.3 263.6 301.2 240.6 268.3 276 197 197  
16-May 16 16 15.6 10.6 137.6 60.0 19.0 247.8   255.6 254.6 285.1 326.1 257.1 289.3 300 224 224  
17-May 17 17 16.2 11.2 148.9 61.2 20.2 268.0   276.8 276.1 309.2 352.1 276.4 309.5 323 244 244  
18-May 18 18 16.4 11.4 160.3 61.6 20.6 288.6   298.7 295.5 332.8 379.4 297.5 331.4 348 263 263  
19-May 19 19 15.4 10.4 170.7 59.7 18.7 307.3   320.9 312.1 353.9 405.5 320.8 355 373 286 286  
20-May 20 20 12.9 7.9 178.6 55.2 14.2 321.5   343.2 326.2 378.0 431.5 345.4 376.8 398 310 310  
21-May 21 21 13.4 8.4 187.0 56.1 15.1 336.6   365.6 341.1 405.1 455.7 370.5 396.2 425 335 335  
22-May 22 22 15.6 10.6 197.6 60.1 19.1 355.6   387.7 356.9 433.0 479.1 392.0 413.7 449 361 361  
23-May 23 23 16.8 11.8 209.4 62.3 21.3 376.9   409.3 373.9 461.6 501.5 409.8 429.3 471 387 387  
24-May 24 24 18.0 13.0 222.4 64.4 23.4 400.3   431.1 391.7 488.8 523.6 426.2 442.6 495 415 415  
25-May 25 25 18.4 13.4 235.8 65.1 24.1 424.4   453.5 411.0 514.4 544.2 445.3 458 522 442 442  
26-May 26 26 18.9 13.9 249.7 66.1 25.1 449.5   476.6 432.3 541.5 563.6 466.9 475.8 550 469 469  
27-May 27 27 18.4 13.4 263.1 65.2 24.2 473.6   500.5 455.3 571.5 584.0 489.8 496.3 577 496 496  
28-May 28 28 17.9 12.9 276.0 64.2 23.2 496.9   526.8 479.4 604.8 607.7 513.4 518.2 619 522 522  
29-May 29 29 17.5 12.5 288.5 63.5 22.5 519.4   552.2 505.2 638.5 633.0 536.6 540 646 548 548  
30-May 30 30 17.2 12.2 300.8 63.0 22.0 541.4   577.6 530.5 671.0 657.6 560.5 562.2 674 571 571  
31-May 31 31 17.7 12.7 313.5 63.8 22.8 564.2   603.2 554.2 703.6 681.6 586.0 584.3 702 595 595  
1-Jun 1 32 17.8 12.8 326.3 64.1 23.1 587.3   629.2 579.4 736.0 703.7 612.9 607.1 732 619 619  
2-Jun 2 33 18.6 13.6 339.9 65.4 24.4 611.8   655.1 604.9 768.3 724.8 639.3 630.7 762 644 644  
3-Jun 3 34 18.8 13.8 353.7 65.9 24.9 636.7   680.6 630.7 802.3 743.6 666.0 654 793 669 669  
4-Jun 4 35 18.2 13.2 366.9 64.8 23.8 660.4   705.5 657.5 838.4 764.5 692.5 675.5 825 691 691  
5-Jun 5 36 18.5 13.5 380.4 65.2 24.2 684.6   730.8 685.0 877.0 787.1 717.3 697.6 858 714 714  
6-Jun 6 37 18.8 13.8 394.2 65.8 24.8 709.5   756.8 713.4 916.9 811.2 739.2 721 892 737 737  
7-Jun 7 38 18.9 13.9 408.0 66.0 25.0 734.5   782.8 742.2 956.1 835.3 763.8 742.4 925 762 762  
8-Jun 8 39 19.7 14.7 422.7 67.5 26.5 760.9   807.3 770.5 984.7 859.6 790.2 763.8 950 784 785  
9-Jun 9 40 21.2 16.2 439.0 70.2 29.2 790.1   831.8 799.3 1011.1 885.7 815.5 786.9 973 803 809  
10-Jun 10 41 22.4 17.4 456.4 72.3 31.3 821.4   856.1 827.8 1040.3 903.9 840.1 811.5 998 823 833  
11-Jun 11 42 22.7 17.7 474.1 72.8 31.8 853.3   880.1 857.0 1066.9 920.7 860.6 837.4 1027 844 856  
12-Jun 12 43 22.3 17.3 491.3 72.1 31.1 884.4   903.4 885.9 1086.9 938.8 879.0 862.2 1059 864 880  
13-Jun 13 44 22.0 17.0 508.3 71.6 30.6 914.9   926.9 914.2 1109.2 957.4 900.3 883.1 1088 888 903  
14-Jun 14 45 21.5 16.5 524.8 70.7 29.7 944.6   950.2 934.6 1130.5 978.3 925.6 904.7 1114 914 927  
15-Jun 15 46 19.7 14.7 539.5 67.5 26.5 971.1   974.4 959.8 1150.5 999.7 953.3 929.5 1140 940 951  
16-Jun 16 47 19.4 14.4 553.9 66.9 25.9 997.0   998.9 988.4 1172.4 1021.9 977.5 956.3 1164 968 975  
17-Jun 17 48 0.0 -5.0 548.9 32.0 -9.0 988.0   1023.9 1016.9 1198.6 1046.6 999.4 983.9 1187 993 998  
18-Jun 18 49 0.0 -5.0 543.9 32.0 -9.0 979.0   1049.5 1044.5 1223.3 1069.7 1025.7 1013 1215 1021 1022  
19-Jun 19 50 0.0 -5.0 538.9 32.0 -9.0 970.0   1075.6 1072.7 1246.8 1092.4 1053.5 1037 1247 1052 1045  
20-Jun 20 51 0.0 -5.0 533.9 32.0 -9.0 961.0   1101.6 1097.3 1274.1 1115.0 1079.2 1066 1276 1084 1069  
21-Jun 21 52 0.0 -5.0 528.9 32.0 -9.0 952.0   1127.0 1119.3 1300.7 1137.1 1104.7 1096 1303 1114 1093  
22-Jun 22 53 0.0 -5.0 523.9 32.0 -9.0 943.0   1151.2 1146.2 1321.6 1160.0 1128.4 1120 1331 1139 1116  
23-Jun 23 54 0.0 -5.0 518.9 32.0 -9.0 934.0   1175.9 1177.2 1345.6 1182.0 1149.7 1148 1357 1165 1140  
24-Jun 24 55 0.0 -5.0 513.9 32.0 -9.0 925.0   1201.0 1203.5 1370.9 1209.0 1170.1 1179 1384 1191 1164  
25-Jun 25 56 0.0 -5.0 508.9 32.0 -9.0 916.0   1225.8 1227.1 1393.3 1235.2 1190.4 1210 1412 1214 1187  
26-Jun 26 57 0.0 -5.0 503.9 32.0 -9.0 907.0   1249.7 1252.6 1416.4 1257.8 1210.1 1240 1436 1236 1211  
27-Jun 27 58 0.0 -5.0 498.9 32.0 -9.0 898.0   1273.0 1279.3 1440.8 1279.3 1231.8 1265 1455 1262 1235  
28-Jun 28 59 0.0 -5.0 493.9 32.0 -9.0 889.0   1297.8 1308.6 1466.0 1301.6 1255.2 1292 1477 1287 1258  
29-Jun 29 60 0.0 -5.0 488.9 32.0 -9.0 880.0   1322.5 1334.2 1489.3 1327.1 1279.6 1320 1501 1309 1282  
30-Jun 30 61 0.0 -5.0 483.9 32.0 -9.0 871.0   1346.8 1358.9 1512.6 1356.1 1300.7 1345 1525 1335 1306  
1-Jul 1 62 0.0 -5.0 478.9 32.0 -9.0 862.0   1371.8 1382.1 1535.8 1384.1 1321.7 1373 1552 1361 1329  
2-Jul 2 63 0.0 -5.0 473.9 32.0 -9.0 853.0   1397.0 1405.4 1560.3 1406.8 1345.2 1404 1579 1385 1353  
3-Jul 3 64 0.0 -5.0 468.9 32.0 -9.0 844.0   1422.6 1431.5 1583.9 1429.7 1367.6 1435 1604 1411 1377  
4-Jul 4 65 0.0 -5.0 463.9 32.0 -9.0 835.0   1447.2   1461.4 1607.6 1452.5 1390.1 1462 1628 1438 1400  
5-Jul 5 66 0.0 -5.0 458.9 32.0 -9.0 826.0   1471.3 1483.0 1633.2 1476.0 1415.2 1487 1652 1464 1424  
6-Jul 6 67 0.0 -5.0 453.9 32.0 -9.0 817.0   1494.6 1501.1 1659.3 1497.1 1440.3 1513 1676 1487 1448  
7-Jul 7 68 0.0 -5.0 448.9 32.0 -9.0 808.0   1517.1 1518.9 1681.0 1518.3 1463.0 1537 1698 1512 1471  
8-Jul 8 69 0.0 -5.0 443.9 32.0 -9.0 799.0   1540.6 1548.6 1700.5 1540.4 1484.7 1561 1719 1536 1495  
9-Jul 9 70 0.0 -5.0 438.9 32.0 -9.0 790.0   1563.8 1575.7 1721.0 1563.3 1505.3 1586 1739 1562 1519  
10-Jul 10 71 0.0 -5.0 433.9 32.0 -9.0 781.0   1587.8 1603.8 1742.9 1587.2 1528.1 1609 1760 1590 1542  
11-Jul 11 72 0.0 -5.0 428.9 32.0 -9.0 772.0   1611.7 1629.7 1763.7 1612.2 1551.3 1632 1780 1619 1566  
12-Jul 12 73 0.0 -5.0 423.9 32.0 -9.0 763.0   1635.3 1653.3 1785.1 1639.4 1573.9 1654 1801 1646 1590  
13-Jul 13 74 0.0 -5.0 418.9 32.0 -9.0 754.0   1659.2 1677.4 1806.1 1665.7 1598.3 1676 1823 1672 1613  
14-Jul 14 75 0.0 -5.0 413.9 32.0 -9.0 745.0   1683.0 1702.5 1828.2 1689.7 1623.9 1699 1846 1698 1637  
15-Jul 15 76 0.0 -5.0 408.9 32.0 -9.0 736.0   1706.5 1726.4 1851.0 1712.5 1647.5 1722 1869 1722 1660  
16-Jul 16 77 0.0 -5.0 403.9 32.0 -9.0 727.0   1730.5 1749.5 1874.5 1734.4 1671.3 1746 1895 1747 1684  
17-Jul 17 78 0.0 -5.0 398.9 32.0 -9.0 718.0   1754.5 1774.8 1898.1 1757.3 1694.5 1770 1921 1773 1708  
18-Jul 18 79 0.0 -5.0 393.9 32.0 -9.0 709.0   1778.4 1801.8 1920.2 1780.7 1716.5 1793 1945 1799 1731  
19-Jul 19 80 0.0 -5.0 388.9 32.0 -9.0 700.0   1802.3 1827.5 1942.3 1803.6 1738.3 1815 1969 1824 1755  
20-Jul 20 81 0.0 -5.0 383.9 32.0 -9.0 691.0   1826.7 1851.9 1964.8 1827.3 1762.2 1838 1994 1850 1779  
21-Jul 21 82 0.0 -5.0 378.9 32.0 -9.0 682.0   1850.6 1875.5 1987.8 1849.1 1788.0 1861 2018 1875 1802  
22-Jul 22 83 0.0 -5.0 373.9 32.0 -9.0 673.0   1874.0 1899.5 2010.1 1869.9 1812.6 1885 2042 1900 1826  
23-Jul 23 84 0.0 -5.0 368.9 32.0 -9.0 664.0   1897.5 1923.9 2032.2 1892.2 1836.0 1910 2064 1926 1850  
24-Jul 24 85 0.0 -5.0 363.9 32.0 -9.0 655.0   1920.6 1949.5 2053.5 1914.9 1857.1 1936 2087 1950 1873  
25-Jul 25 86 0.0 -5.0 358.9 32.0 -9.0 646.0   1943.6 1976.4 2075.5 1937.9 1877.6 1960 2109 1972 1897  
26-Jul 26 87 0.0 -5.0 353.9 32.0 -9.0 637.0   1966.3 2001.5 2097.1 1959.5 1898.5 1984 2132 1994 1921  
27-Jul 27 88 0.0 -5.0 348.9 32.0 -9.0 628.0   1988.6 2025.2 2119.2 1980.8 1919.9 2006 2153 2016 1944  
28-Jul 28 89 0.0 -5.0 343.9 32.0 -9.0 619.0   2010.6 2048.6 2140.5 2001.9 1941.5 2029 2174 2037 1968  
29-Jul 29 90 0.0 -5.0 338.9 32.0 -9.0 610.0   2031.5 2063.9 2162.4 2021.1 1963.0 2051 2195 2058 1992  
30-Jul 30 91 0.0 -5.0 333.9 32.0 -9.0 601.0   2051.9 2079.0 2184.0 2039.6 1984.2 2074 2217 2080 2015  
31-Jul 31 92 0.0 -5.0 328.9 32.0 -9.0 592.0   2073.0 2094.0 2206.4 2056.9 2006.3 2097 2240 2102 2039  
1-Aug 1 93 0.0 -5.0 323.9 32.0 -9.0 583.0   2094.3 2109.7 2229.2 2073.9 2029.4 2120 2262 2124 2063  
2-Aug 2 94 0.0 -5.0 318.9 32.0 -9.0 574.0   2116.2 2133.2 2252.3 2092.1 2051.0 2144 2284 2146 2086  
3-Aug 3 95 0.0 -5.0 313.9 32.0 -9.0 565.0   2138.0 2156.0 2275.5 2110.6 2073.4 2168 2304 2169 2110  
4-Aug 4 96 0.0 -5.0 308.9 32.0 -9.0 556.0   2159.8 2177.5 2298.3 2129.9 2095.8 2191 2325 2191 2134  
5-Aug 5 97 0.0 -5.0 303.9 32.0 -9.0 547.0   2181.5 2197.8 2321.2 2149.5 2118.1 2215 2346 2212 2157  
6-Aug 6 98 0.0 -5.0 298.9 32.0 -9.0 538.0   2203.7 2218.3 2344.2 2169.7 2140.5 2240 2368 2232 2181  
7-Aug 7 99 0.0 -5.0 293.9 32.0 -9.0 529.0   2225.4 2240.0 2365.8 2189.4 2163.9 2263 2388 2253 2205  
8-Aug 8 100 0.0 -5.0 288.9 32.0 -9.0 520.0   2244.8   2386.4 2207.4 2186.6 2285 2409 2275 2228  
9-Aug 9 101 0.0 -5.0 283.9 32.0 -9.0 511.0   2266.0   2405.6 2225.0 2209.7 2308 2431 2295 2252  
10-Aug 10 102 0.0 -5.0 278.9 32.0 -9.0 502.0   2287.4   2425.2 2243.9 2231.8 2332 2454 2316 2275  
11-Aug 11 103 0.0 -5.0 273.9 32.0 -9.0 493.0   2309.0   2445.2 2263.0 2253.7 2354 2477 2338 2299  
12-Aug 12 104 0.0 -5.0 268.9 32.0 -9.0 484.0   2330.5   2465.2 2283.2 2276.1 2377 2499 2358 2323  
13-Aug 13 105 0.0 -5.0 263.9 32.0 -9.0 475.0   2351.5   2484.8 2302.8 2296.9 2400 2521 2378 2346  
14-Aug 14 106 0.0 -5.0 258.9 32.0 -9.0 466.0   2372.5   2503.9 2321.8 2316.6 2423 2544 2398 2370  
15-Aug 15 107 0.0 -5.0 253.9 32.0 -9.0 457.0   2393.2   2522.6 2340.2 2335.7 2446 2566 2417 2394  
16-Aug 16 108 0.0 -5.0 248.9 32.0 -9.0 448.0   2413.7   2541.5 2358.4 2352.8 2470 2588 2437 2417  
17-Aug 17 109 0.0 -5.0 243.9 32.0 -9.0 439.0   2434.4   2560.2 2377.2 2369.3 2495 2611 2456 2441  
18-Aug 18 110 0.0 -5.0 238.9 32.0 -9.0 430.0   2454.6   2578.2 2394.1 2387.0 2518 2634 2475 2465  
19-Aug 19 111 0.0 -5.0 233.9 32.0 -9.0 421.0   2475.9   2597.5 2412.5 2408.1 2541 2656 2494 2488  
20-Aug 20 112 0.0 -5.0 228.9 32.0 -9.0 412.0   2497.9   2617.7 2434.3 2431.5 2566 2678 2513 2512  
21-Aug 21 113 0.0 -5.0 223.9 32.0 -9.0 403.0   2520.4   2636.6 2456.4 2454.3 2592 2701 2533 2536  
22-Aug 22 114 0.0 -5.0 218.9 32.0 -9.0 394.0   2543.0   2656.0 2480.4 2476.2 2617 2725 2554 2559  
23-Aug 23 115 0.0 -5.0 213.9 32.0 -9.0 385.0   2565.5   2676.9 2504.8 2499.9 2642 2748 2573 2583  
24-Aug 24 116 0.0 -5.0 208.9 32.0 -9.0 376.0   2587.3   2696.5 2525.0 2524.6 2667 2773 2591 2607  
25-Aug 25 117 0.0 -5.0 203.9 32.0 -9.0 367.0   2609.0   2716.3 2543.9 2547.3 2690 2796 2611 2630  
26-Aug 26 118 0.0 -5.0 198.9 32.0 -9.0 358.0   2630.2   2735.7 2564.5 2567.4 2714 2818 2631 2654  
27-Aug 27 119 0.0 -5.0 193.9 32.0 -9.0 349.0   2651.6   2755.9 2586.2 2590.2 2739 2839 2648 2678  
28-Aug 28 120 0.0 -5.0 188.9 32.0 -9.0 340.0   2673.3   2775.2 2608.2 2610.5 2763 2861 2667 2701  
29-Aug 29 121 0.0 -5.0 183.9 32.0 -9.0 331.0       2794.6 2631.2   2787 2882 2688 2725  
30-Aug 30 122 0.0 -5.0 178.9 32.0 -9.0 322.0       2814.0 2653.8   2811 2905 2710 2749  
31-Aug 31 123 0.0 -5.0 173.9 32.0 -9.0 313.0       2833.3 2675.0   2837 2930 2730 2772  
1-Sep 1 124 0.0 -5.0 168.9 32.0 -9.0 304.0       2851.5 2694.4   2862 2955 2750 2796  
2-Sep 2 125 0.0 -5.0 163.9 32.0 -9.0 295.0         2714.2   2887 2979 2769 2819  
3-Sep 3 126 0.0 -5.0 158.9 32.0 -9.0 286.0         2736.8   2914 3004 2787 2843  
4-Sep 4 127 17.7 -5.0 153.9 63.8 22.8 308.9         2758.3   2905 3029 2805 2867  
5-Sep 5 128 17.7 -5.0 148.9 63.8 22.8 331.7         2779.4   2896 3053 2824 2890