Root-zone Application of Insecticides in Gelatin Capsules for the Control of Rice Insect Pests

살충제(gelatin capsule 입)의 수도근부처리에 의한 수도해충 방제효과

During 1973 a field experiment was carried out to evaluate effectiveness of the root zone application of insecticides in medical gelatin capsules for control of several rice insect pests and dwarf virus disease. At three days after transplanting the capsules were pushed by hand about 2.5cm into the soil, near roots of Tongil rice plants. At the given day intervals number of leaf-and plant-hoppers on the hills were recorded by direct count, and dead hearts and white heads by stem borers and dwarf virus infected hills were observed in the experiment plots. Finally grain yields were measured. The percentages of dead hearts and white heads in all the plots were too low for evaluating the effectiveness of insecticides against the striped rice borers. Carbofuran of the insecticides tested was relatively effective against green rice leafhopper (Nephotettixcincticeps) and small brown planthopper (Laodelphax striatellus), although small number of insects on the hills were recorded. Relatively small number of white-backed planthopper (Sogatella furcifera) was occured in the BPMC and Diazinon treated plots. BPMC and Carbofuran were highly effective against the brown planthopper (Nilaparvata lugens) to 80 days after treatment. Incidence of dwarf virus disease was least in the plots of Carbofuran treatment. The highest grain yield was recorded in the plots treated with Carbofuran, and it seemed to be related with good protection from the dwarf virus disease and leaf-and plant-hoppers.

의약용 Capsuel에 넣은 입제형 살충제 BPMC, Carbofuran, Cartap, Chlorphenamidine-HCl, Cytrolane, Diazinon의 단일회 수도근부처리로서 수도 전생육기간에 걸친 이화멸충, 멸구, 매미충류 및 Virus 병의 방제효과를 검정하기 위해 포장시험을 실시하여 아래와 같은 결과를 얻었다. (1) 이화명충은 발생이 적었기 때문에 약제간에 큰 차이는 볼 수 없었지만 약제처리후 50일에서 이화명충 1화기 심고경율 Cartap 0, Carbofuran 0.1, Chlorphenamidine 0.4, Cytrolane 0.5, BPMC 1.8, Diazinon 2.2이었으며 2화기 백수율은 BPMC에서 $1.2\%$이었을 뿐 그밖에 약제처리구에서는 백수가 없었다. (2) 끝동매미충과 애멸구에 대해서는 BPMC와 Diazinon 처리구에서 비교적 낮은 밀도를 보였다. 벼멸구에 대해서는 BPMC와 Carbofuran에서 서식밀도가 현저히 낮아 그 방제효과가 좋았으나 Cartap, Chlorphenamidine, Cytrolane 및 Diazinon의 효과는 거의 기대할 수 없었다. (3) 오갈병의 발병주율은 Carbofuran이 $2.4\%$, Cytrolane $4.5\%$, Chlorphenamidine $7.9\%$, Diazinon $8.0\%$ BPMC$8.1\%$, Cartap $14.5\%$, Diazinon 입제수면 시용 $7.8\%$, 무처리 $13.1\%$로서 Carbofuran 처리구에서 오갈병의 발병율이 가장 낮았다. 줄무늬잎마름병의 발생은 전혀 없었는데 그 원인은 통일벼는 줄무늬잎마름병에 저항성품종이기 때문인 것 같다. (4) 벼의 수량은 무처리 5,814kg/ha에 비하여 Carbofuran 6,649kg, Cytrolane 6,340kg, BPMC 6,315kg, Chlorphenamidine 6,265kg, Cartap 6,164kg, Diazinon 5,944kg, Diazinon 입제 수면시용 6,102kg로서 Carbofuran 처리구에서 벼의 수량이 가장 높았다. (5) Carbofuran 처리구에서 높은 수량을 보인 것은 Carbofuran 처리구에서 멸구, 매미충류의 밀도가 낮았고 오갈병의 발병율이 낮은데서 온 결과인 것 같다.