The primary
purpose of this study was to develop a bioeconomic
simulation model to examine the issue of harvesting asparagus,
with the objective to determine the impact of different management
strategies in the harvest. The dissertation is separated in three
articles. In the first article the model was successfully validated
using data from different locations for four consecutive years in
Washington. The impact of the minimum wage requirements was evaluated
in terms of yield and profit for both processed and fresh asparagus.
The traditional harvest interval of 24-hour was compared to a more
frequent interval (12-hour) and a less frequent intervals (48-hour).
Manual harvest with the interval of 12-hour showed to be the best
results in terms of yields and profits for both processed and fresh
asparagus.
In the second article, break-even recovery rates
were calculated. The average break-even recovery rate for the period
1989-2004 was 70.15 percent for the 24 hours harvesting interval
in order for the mechanical harvester to be economically acceptable
in place of hand harvesting. The 28, 32, and 36-hour harvesting
intervals produced break-even recovery rates that were not statistically
different from the 24 hours interval. By increasing the manual harvesting
costs from US$0.51/kg to US$0.60/kg the recovery rate needed by
the mechanical harvester to break-even with manual harvesting decreased
from 70.15 percent to 61.30 percent.
In the third article, the CHO accumulation was
included in the bioeconomic simulation model of asparagus to examine
the inter-year effect of harvesting. The results using the actual
level of CHO used showed yields and production consistent with actual
results. By increasing the CHO level for stopping the harvest to
210 g/plant, an increase in terms of net present value, profit,
and yield is recorded. Results with price trends with favorable
prices at the end of the season confirmed that the CHO level of
210 g/plant is the one that can provide the highest performances
in terms of net present value, yields, and profits. |
