One advantage of Vapam is that it can be applied through an irrigation system.

 However, soil temperature and moisture can dramatically influence the effectiveness of this

 chemical. In addition, another major disadvantage of Vapam is the waiting period prior to

 entering the treated area, which is dependent on environmental conditions. Planted crops will

 incur damage, or be killed, if the chemical is still in the soil at the time of planting (Noling,

 1991). Finally, Vapam is not as effective in control of diseases and nematodes when compared

 to methyl bromide (Overman et al., 1987). Erratic or reduced control by Vapam is a common

 occurrence, and more material may be required to approach desirable levels of control. As a

 result of increased amounts of Vapam applied for effective control, the question arises as to how

 much leaches through the soil and enters the water table (for a brief review of information

 derived from the specimen label for Vapam, refer to Appendix C-3).


 Telone II and Telone C-17

 Telone II is a restricted use pesticide, which contains the active ingredient 1,3-

 dichloropropene. This chemical can be used in crop production of eggplant, tomato, pepper,

 strawberry, melon, cucumber, and citrus, as well as other crops. Telone C-17 is a multi-

 purpose, preplant soil fumigant containing 77.9% 1,3 dichloropropene and 16.5% chloropicrin.

 This chemical can be used for control of nematodes, soilborne fungi, and weeds, for some high

 value field and vegetable crops (Dunn and Noling, 1993). The chloropicrin (16.5%) controls

 some soilborne fungi, but not Sclerotonia or Rhizoctonia species.

 Information regarding water contamination remains unclear. The manufacturer suspended

sale of Telone in south Florida prior to fall 1993, although it could legally still be used in south

Florida. Telone is currently sold and distributed in south Florida on a limited basis, and it is