주입구멍의 크기와 수관 상태에 따른 약액의 수간주입 속도를 알아보고자 주입구멍의 지름을 5mm와 10mm로 하고 수관을 온전, 절반 제거, 1/4씩 두 곳 제거 등 세 수준으로 구분하여 식용색소 적색3호 수용액을 수간주입하고 일정 시간별로 주입량을 측정하였다. 수간주입 4시간 뒤에 대부분의 느티나무에서 약액이 30% 이상 흡수된 상태였으며, 7시간 후에서는 7그루에서 모든 약액이 흡수된 것을 확인하였다. 48시간 후에는 처리 조건과 방법에 관계없이 한 그루를 제외한 모든 개체에서 주입액이 완전흡수되었다. 주입구멍의 크기나 수관의 상태 등은 수간주입 속도와 통계적 유의성이 없었다. 주간에서 움트는 잔가지의 잎들은 수간주입 후 24시간에 붉은색을 나타내기 시작하였으며, 48시간 후에는 수관의 잎들도 엽육조직이 붉게 변하여 수관도 붉은 색을 보였다. 수관이 변색된 나무의 수도 처리 내용 간에 통계적 유의차가 없었다. 줄기 단면 관찰에서도 주입구멍의 크기나 수관 상태 간에 적색주입액의 분포 차이가 없었다. 본 연구의 결과로부터 주입구멍의 크기나 수관의 엽량은 수간주입의 효율에 영향을 미치지 않음이 확인되었다. 따라서 큰 상처를 남기는 지름 10mm 주입구멍보다는 지름 5mm 주입구멍을 사용 하는 것이 나무의 자가치유를 도와주는 올바른 수간주입법이라고 할 수 있다.
최근 수목 병해충을 방제, 예방하기 위해 나무주사법이 많이 사용되고 있다. 나무주사법은 기상에 상관없이 약제처리가 가능하며, 약제사용량 감소와 천적등 비표적 생물에 대한 영향을 줄일 수 있다는 장점이 있다. 하지만 현재 국내에서 나무주사법은 산림 해충을 대상으로만 등록, 적용되어 있을 뿐, 과수에 등록된 제품은 없다. 과수에 나무주사법이 적용되기 위해서는 농약잔류와 약효에 대한 연구가 필요하다. 본 연구에서는 복숭아(천중도)에 Acetamiprid 10% SL을 나무주사 후, 잔류성과 약효를 조사하여 실용가능성을 확인하였다. 약제가 나무주사된 나무는 복숭아 벚나무깍지벌레(Pseudaulacaspis prunicola)에 대하여 방제효과가 있으나, 가지별로 불균일한 약효와 잔류성을 보여 향후 수형, 흉고직경 등을 고려한 나무주사제의 처리법 최적화에 대한 연구가 지속적으로 필요할 것으로 생각된다.
Trunk injection of nematicides was applied to prevent pine wilt disease (PWD). Although the trunk injection of nematicides was effective to PWD prevention, it was not effective to a vector, Monochamus alternatus. Thus, This study was investigated for the insecticidal activity and the effect of oviposition deterrence by injecting to pine trees with systemic insecticides such as Acetamiprid SC 10%, Imidacloprid DC (20%), and Thiamethoxam DC (15%). As a results, mortality of M. alternatus adults was 100% at 56 days after trunk injection. Percentage of M. alternatus adults moved to a young black pine tree by trunk injection of Imidacloprid DC (20%) and Thiamethoxam DC (15%) in screen cage (4.0×2.0×2.5m) was 76.7% and 70.0%, respectively. But the mortality of M. alternatus adults showed 100%. Percentage of M. alternatus adults moved to the treated and untreated young black pine trees by trunk injection of Acetamiprid SC (10%) in screen cage (4.0×2.0×2.5m) were 25.9% and 49.5% at 1st day and 3rd day after treatment, respectively. Percentage of M. alternatus adults oviposited to treated pine logs at 3month after trunk injection of liquid mixture of Acetamiprid SC (10%) and Emamectin benzoate EC (2.15%) in screen cage (72×72×100㎝) was 25%. But, untreated pine logs was 100%
The most effective methods against pine wilt disease (Bursaphelenchus xylophilus, PWD), black pine bast scale (Matsucoccus thunbergianae), pine needle gall midge (Thecodiplosis japonensis) is the trunk injection of insecticides. The period of trunk injection that was considered with ecology and physiology of pests such as pine wilt disease, black pine bast scale and pine needle gall midge, was applied from Dec. to next Feb. and June, Dec. respectively. And there are differences in quantities of being injected chemicals to pine trees by the period of trunk injection. Thus, we investigated to prevent the effect of insecticides, to estimate the effect under the trunk injection of insecticides for pine trees against pests by the injecting period and time, boring site, opening and shutting of injection site. On Pinuns thunbergii, it was examined to figure out the effect of insecticides by the injecting period, twice a month on a sunny day around 10 AM from January to September. Injecting of insecticides was tested at a dose of 5ml per cm dbh of a pine tree after boring with hand drill at 50 cm high from the ground. As a result, abmectin 1.8% EC and phospamidon 50% SL were injected over 90% of mortalities from the end of January to the middle of March but as time goes by, injecting insecticides tended to decrease. To compare the volume of injecting insecticides in a day, between 10 AM and 2 PM on February 23rd, abamectin 1.8% EC was injected at a dose of 5ml per pine trees with micro pipette after boring with a drill machine at 50 cm high from the ground. As a result, injecting insecticide of a pine which was injected around 10 AM was completely injected and about 90% of the insecticide was injected in case of a pine that was injected around 2 PM. Trunk injection of insecticides was examined to figure out differences of the volume of injected insecticides before and after rain. There was no difference not only the rainfall but also the bored direction.
Trunk injection of nematicides is applied to prevent pine wilt disease(PWD). Although the trunk injection of nematicides is effective to PWD prevention, it is not effective to vector insects such as adults of M. alternatus and M. saltuarius. Thus, This study was investigated for the insecticidal activity and the effect of feeding deterrence by injecting to pine trees with acetamiprid.
For screening effective nematicides, some insecticides were injected to pines on December 30th, 2008 and their insecticidal activities and feeding areas of M. alternatus and M. saltuarius were investigated in the insects breeding dishes (100× 40mm) where put on 1 to 2-year-old twig which was selected from injected pine trees in early June. As a result, insecticidal activity and feeding deterrence of acetamicprid were most effective. Feeding areas of M. alterantus adults, when tested with 1-year-old twig and 2-year-old twig of healthy pine trees, were 170.3±107.0 mm2 and 258.0±123.2 mm2 respectively. And Feeding areas of M. alterantus adults, when tested with 1-year-old twig and 2-year-old twig of pines injected at a dose of 0.3 ml per cm dbh of a pine tree with acetamiprid, were 57.7±72.3 mm2 and 65.7±51.2 mm2 respectively and their mortalities also were 0%, 28.6%. The feeding areas of M. alterantus adults tested with 1-year-old twig and 2-year-old twig of pine trees injected at a dose of 0.6 ml per cm dbh of a pine tree with acetamiprid, were not fed on it and the mortalities were 28.0%, 57.1% respectively.
In case of the feeding areas of M. saltuarius adults, when tested with 1-year-old twig and 2-year-old twig of healthy pine trees, it was 112.±35.1 mm2 and 159.2±65.2 mm2 respectively. And the feeding areas of M. saltuarius adults, when tested
with 1-year-old twig and 2-year-old twig of injected pine trees at a dose of 0.3 ml per cm dbh of a pine tree with acetamiprid were 0.61±0.0 mm2 and 8.1±12.4 mm2 and both mortalities were 23.1%. Although M. saltuarius adults, when tested with 1-year-old twig of a pine tree injected at a dose of 0.6 ml per cm dbh of a pine tree with acetamiprid, were not fed on it but M. saltuarius adults tested with 2-year-old twig of the same pine tree were 2.0±3.7 mm2 and their mortalities were 53.8%, 61.5% respectively.
We investigated insecticidal activities, the effects of feeding deterrence of acetamiprid for vector insects where fed twigs of injected pines by stop up hole with a cork or not, and the trunk injection to pine trees at a dose of 0.5, 1 ㎖ per ㎝ dbh of a pine tree with acetamiprid on the early June. As a result, all of the vector insects were not fed and the feeding area was within 11 ㎟ and the mortality of M. alternatus was 70%.