Task 5: Pesticide Use Reports
In a report written for the Almond Board of California by Susan Bassein and
Lynn Epstein both from the University of California Davis, titled “Reduction
in Use of Organophosphates in Almond Orchards During the Rainy Season in
California” shows that the amount of organophosphates are being applied with
much more discretion today than in the early 1990’s. By accessing the Pesticide Use Reports from 1990 to 2000,
they have shown a reduction of growers using organophosphate dormant sprays.
The researchers also show the mass of organophosphates applied during the
dormant season was reduced 22 to 57% depending on the region.
Furthermore, they reported a significant increase in use of Bt. The
results are promising, indicating the positive and proactive response the almond
industry has adopted in order to curb organophosphate use.
The results reported here in Year 3 of the Almond PMA show a trend even more
positive than the report submitted by Bassein and Epstein.
According to the Department of Pesticide Regulation, 2000 was the second
consecutive year of reduction in pesticide use statewide.
The report highlights almonds as having reduced pesticide use more than
any other crop, with a decrease of more than 3 million pounds from 1999 to 2000. With the increasing amount of commercial almond acreage, the
amount of organophosphates applied per acre are decreasing and the use of Bt is
remaining fairly steady across the state in commercial almond orchards.
Figure 5.1 shows the increase in commercial almond acreage in the ten
major almond growing counties in California: Butte, Kern, Stanislaus, Colusa,
Fresno, Glenn, Madera, Merced, San Joaquin, and Tulare.
Organophosphates, carbamates, pyrethroids and Bt use were tracked in almonds
using the Pesticide Use Reports from 1995-2000 and reported here as pounds per
acre.
Organophosphates:
Organophosphates used in these results are: azinphos-methyl, chlorpyrifos,
ddvp, diazinon, disulfoton, fenamiphos, malathion, methidathion, naled,
parathion, and phosmet. Since each
county has various amounts of almond acreage, pounds per acre were analyzed.
Figure 5.2 shows the use of organophosphates on California almonds from
1995-2000. Most organophosphate use
occurs in January and July, corresponding to the dormant and hullsplit sprays.
Total organophosphate use has dropped due in part to growers realizing
that a dormant spray of organophosphate is not always needed.
Carbamates:
Carbamates used in these results are methomyl and carbaryl.
Carbamate use in California has been reduced by more than half since
1997, Figure 5.3. January and July
have significantly more carbamate applications than any other month.
Again, these two months correspond to dormant and hullsplit sprays.
Pyrethroids:
Pyrethroids used in these calculations are esfenvalerate, permethrin and
pyrethrin. The pounds per acre used
in 1995 to 2000 are shown in Figure 5.4
Bacillus thuringiensis:
There has been a significant increase in the use of Bt in commercial almonds
since 1990 when there were no applications of Bt to almonds in the state.
The pounds of Bt applied per acre have risen steadily from 1990 to 1995
when virtually no Bt was applied statewide and after 1995 remains fairly steady,
given the increase in new plantings, Figure 5.5.
Bt is applied mainly in February and March.
Bt use spikes again in July.
