EFFECTS OF NEMATICIDES AND CULTIVARS ON ROTYLENCHULUS-RENIFORMIS AND FLUE-CURED TOBACCO YIELD

Main plots of tobacco cultivars were split into subplots treated or not treated with 1,3-D + chloropicrin. Some differences (P = 0.05) occurred for tobacco yield, value, and R. reniformis populations among the 12 cultivars tested. Treatment increased yields an average of 8.5%, but a significant cultivar x fumigation interaction did not occur. In a nematicide test, six of nine non-fumigant and fumigant nematicides significantly increased the value of tobacco cv. Coker 371-Gold by an average of $1,475/ha and decreased populations of Rotylenchulus reniformis. Similar results were not obtained using the cv. K 326 in another year. Nematode population levels often declined from the first sampling to the second, especially when initial numbers were relatively high. These are the first reported field studies involving management of R. reniformis on tobacco in the United States.