Economic Importance of 1,3-Dichloropropene or Fenamiphos to Manage Meloidogyne javanica in Florida Tobacco

Twelve tobacco (Nicotiana tabacum L.) nematicide field trials were conducted over ten years in north-central Florida, U. S. A., on sites containing fine sandy soil. In each of these trials, 1,3- dichloropropene (1,3-D), fenamiphos 3 SC and a control were utilized. The 1,3-D treatments were applied with a single chisel in the row at rates between 68 and 102 kg a.i./ha. Fenamiphos was applied broadcast at 6.7 kg a.i. in 185 L water/ha and double disc-incorporated. Plots were two rows wide (1.12 m wide/row) and 6.1 m long. Tests were arranged in a randomized complete block design with six replicates. Tobacco leaves were harvested 3-4 times upon maturity and cured weights recorded. Root-gall mdex ratings were made at or near final harvest from four plants in each plot and rated on a 0-4 scale where 0=0 and 4 76% of the root system galled. Compared to untreated controls, 1,3-D treatments increased yield of cured tobacco by 943 kg/ha providing added gross average value of $3134 (U.S.)/ha