the alternative production practices used to grow the first crop in the double cropping
system. It is assumed that the alternative used for the first crop will be the alternative
used in a double cropping system. Preharvest cost changes are expected to range from a
decrease of $61 per acre for tomatoes and cucumbers grown in a double cropping system
in Southwest Florida to an increase of $37 for peppers and cucumbers grown in a double
cropping system in Palm Beach County, Florida. Yields will be impacted by the loss of
methyl bromide as certain pests will become re-established and more difficult to manage
following a first crop. It is expected that yields on these second crops will decline 15%
when methyl bromide is no longer available. The low impact scenario assumes a 7%
decline in yields and the high impact scenario assumes a 30% decline in yields for these
crops.


EMPIRICAL RESULTS

 The model was solved using GAMS programming software. The analysis of
impacts from switching to an alternative for methyl bromide was conducted in two parts.
First the model was solved with parameters that assumed continued use of methyl
bromide. This solution provided the baseline for comparison to other solutions where the
parameters of the model were adjusted to reflect a ban on methyl bromide use. The
adjustments that are made in the parameters reflect changes in production costs and
changes in yield in switching to the alternatives. Three initial scenarios beyond the
baseline were solved with the model. The first scenario assumed the next best alternative
given projections on expected cost and yield impacts that were developed from
workshops held in Florida and California to discuss alternatives to methyl bromide. A
low impact scenario was then solved where yield impacts were reduced to reflect lower
impacts than those identified at the methyl bromide workshops. The third scenario was
solved where yield impacts were assumed to be larger than those developed in the
workshops. The cost impacts were assumed to be the same in each scenario. Yield
impacts for each scenario are listed in Table 2.

Baseline Solution

 The solution to the quadratic programming model included equilibrium prices and
quantity consumed by month and crop in each of the four market areas, shipments by
month and crop from each producing area to each market, and the acres planted to each
cropping system in each producing area. The baseline solution performed reasonably well
in replicating the observed pattern of shipments and acres planted for the 1993/94
production season.
 The acres planted by cropping system in each of the producing areas for the
baseline model are shown in Table 3. Total acreage that is planted to tomatoes in Florida
in the baseline model is 49,765 acres, which is slightly more than the 46,500 acres
reported by the Florida Agricultural Statistics Service for the 1993/94 season. The total
baseline acreage of tomatoes is 142,736, which is within 3 % of the total acreage actually
planted in all of the producing areas included in the model for 1994. The baseline acreage