274
C. R. Krishna Murti and T. S. S. Dikshith
(Sprengl) crops sprayed with endosulfan for the control of jassids (Empeasia
devastanus) showed very few residues after 14 days of treatment. Endosulfan
was reduced to 0.21 ppm from an initial deposit of 4.20 ppm after 50 days of
treatment in mustard (Brassicajuncea Coss.). A rapid decline was found in the
residual content of endosulfan in C. arietinum L. (Bengal gram) and also Chick
pea (Dixit et 01 .• 1977; Pandey et 01 .• 1977). Berries of Zizyphus zujuba Lamk
(Ber) showed no residues of endosulfan after 5 days of treatment (Kathpal et
01 .• 1977).
At harvest, maize did not show any residues of endosulfan. The initial
residue levels of 20.23 ppm dissipated quickly, and the insecticide could not be
detected within 4 days (Kavadia et al .• 1977).
Aldrin, endrin, dieldrin, chlordane, endosulfan, and heptachlor have a wide
spectrum of activity, and many members of the cyclodiene group also have a
high mammalian toxicity. Like other chlorinated hydrocarbons, they too are
known to be persistent. Aldrin was found to be converted to dieldrin after
application to green gram at 5% concentration (Agnihotri et 01 .• 1977b). A
maximum concentration of dieldrin was found on the thirtieth day after treatment,
and 80.8% of this was degraded during the subsequent 70-day period. In 180
days, 96.4% of aldrin, 96.4% of dieldrin, and 86.4% of heptachlor were lost
from Delhi soils (Agnihotri et al., 1977a.b). The conversion of both aldrin and
heptachlor into their epoxides was indeed rapid.
Repeated sprays of 0.07% endosulfan on okra, tomato, and brinjal (Solanum
brinjal L.) once in 15 days left initial deposits of 2.74, 4.35, and 3.50 ppm,
respectively, which were reduced to 0.32, 0.0, and 0.20 ppm in 10 days (Rajukkannu et al .• 1976). The initial deposit of endosulfan on mustard leaves was
4.20 ppm, which was reduced to 0.21 in 50 days (Dixit et 01 .• 1977). From an
average initial deposit on fruits of 2. 14 ppm after the first spray, endosulfan
levels rose to 5.14 ppm after the second spray (Kathpal et al .• 1977). The
residues had a half-life of 10.8 days for the first and 8.13 days for the second
spray. BHC and DDT sprayed on spinach showed interesting behavior (Jagalan
and Chopra, 1971).
10.5.3. Carbamate Compounds
In tobacco plants, aldicarb applied to soil in the form of 10% granules at
15 kg/ha persisted for 36 days (Ramaprasad and Joshi, 1974). Investigations on
the dissipation of aldicarb in soil and pea plants revealed that the initial residue
of aldicarb was 13.70 ppm and that its degradation followed first-order kinetics
with a half-life of 17 days (Dixit et 01., 1976). In peas, residues persisted for
110 days and were concentrated in the top portions of the plant. Absorption and
C. R. Krishna Murti and T. S. S. Dikshith
(Sprengl) crops sprayed with endosulfan for the control of jassids (Empeasia
devastanus) showed very few residues after 14 days of treatment. Endosulfan
was reduced to 0.21 ppm from an initial deposit of 4.20 ppm after 50 days of
treatment in mustard (Brassicajuncea Coss.). A rapid decline was found in the
residual content of endosulfan in C. arietinum L. (Bengal gram) and also Chick
pea (Dixit et 01 .• 1977; Pandey et 01 .• 1977). Berries of Zizyphus zujuba Lamk
(Ber) showed no residues of endosulfan after 5 days of treatment (Kathpal et
01 .• 1977).
At harvest, maize did not show any residues of endosulfan. The initial
residue levels of 20.23 ppm dissipated quickly, and the insecticide could not be
detected within 4 days (Kavadia et al .• 1977).
Aldrin, endrin, dieldrin, chlordane, endosulfan, and heptachlor have a wide
spectrum of activity, and many members of the cyclodiene group also have a
high mammalian toxicity. Like other chlorinated hydrocarbons, they too are
known to be persistent. Aldrin was found to be converted to dieldrin after
application to green gram at 5% concentration (Agnihotri et 01 .• 1977b). A
maximum concentration of dieldrin was found on the thirtieth day after treatment,
and 80.8% of this was degraded during the subsequent 70-day period. In 180
days, 96.4% of aldrin, 96.4% of dieldrin, and 86.4% of heptachlor were lost
from Delhi soils (Agnihotri et al., 1977a.b). The conversion of both aldrin and
heptachlor into their epoxides was indeed rapid.
Repeated sprays of 0.07% endosulfan on okra, tomato, and brinjal (Solanum
brinjal L.) once in 15 days left initial deposits of 2.74, 4.35, and 3.50 ppm,
respectively, which were reduced to 0.32, 0.0, and 0.20 ppm in 10 days (Rajukkannu et al .• 1976). The initial deposit of endosulfan on mustard leaves was
4.20 ppm, which was reduced to 0.21 in 50 days (Dixit et 01 .• 1977). From an
average initial deposit on fruits of 2. 14 ppm after the first spray, endosulfan
levels rose to 5.14 ppm after the second spray (Kathpal et al .• 1977). The
residues had a half-life of 10.8 days for the first and 8.13 days for the second
spray. BHC and DDT sprayed on spinach showed interesting behavior (Jagalan
and Chopra, 1971).
10.5.3. Carbamate Compounds
In tobacco plants, aldicarb applied to soil in the form of 10% granules at
15 kg/ha persisted for 36 days (Ramaprasad and Joshi, 1974). Investigations on
the dissipation of aldicarb in soil and pea plants revealed that the initial residue
of aldicarb was 13.70 ppm and that its degradation followed first-order kinetics
with a half-life of 17 days (Dixit et 01., 1976). In peas, residues persisted for
110 days and were concentrated in the top portions of the plant. Absorption and