【目的】探究不同注干剂的残存期和持效期,系统评估5%(质量分数,下同)甲维盐可溶性液剂、5%阿维菌素乳油及1%甲维盐-9%吡虫啉可溶性液剂在松树体内的输导分布、残留动态,为松材线虫(Bursaphelenchus xylophilus)病的科学防控提供技术支撑。【方法】以马尾松(Pinus massoniana)为对象,通过在松树不同部位分层取样,结合液相色谱-质谱法(LC-MS),定量分析药剂在树体内的输导分布与残留动态;在注干后对松树进行松材线虫接种,并设计二次接种以模拟线虫持续侵染,观察并统计松树的发病情况,评估药剂的持续防病效果。【结果】3种注干药剂注干后,都可以输导至马尾松的各个部位,其中主干最多,枝梢略少。在树体内残留总体上可以维持3 a左右,但还是以注药第1年残留最高,第2年次之,第3年进一步衰减。相比之下,5%甲维盐的输导效率和残留量最高,胸径为12 cm的马尾松注药3 a后离注干点1 m处残留含量(质量分数,下同)仍达24.609 mg/kg,3 a后2次接种防治效果仍然可达37.50%;5%阿维菌素因亲脂性强、降解快,3 a后顶枝残留量未检出,2次接种防治效果仅为12.50%;1%甲维盐-9%吡虫啉抑制线虫能力不足,发病最早。同种药剂高剂量(60 mL)注药可以有效提升残留量,胸径为15 cm的马尾松注射60 mL 5%甲维盐1 a后离注干点1 m处的残留含量(质量分数,下同)达33.900 mg/kg,远高于注射30 mL 5%甲维盐的2.405 mg/kg。在注射方式上,微孔注射与自流式在注射1和2 a时并不存在明显差异,均对残留分布影响较小。【结论】3种注干药剂在注干后,可以输导至树体的各个部位。相比之下,5%甲维盐输导效率和残留量更高,是长效防控松材线虫病的优选药剂。3种药剂在注干后均可以较长时间预防松材线虫病,注干1或2 a后的残留量高且防治效果良好,注干3 a后防治效果明显下降。

【Objective】This study aims to investigate the residual efficacy and duration of various trunk-injected agents on masson pine (Pinus massoniana). Assess transport distribution, residue dynamics, and control effects on pine wilt disease. Evaluate 5% (mass fraction) emamectin benzoate soluble liquid, 5% abamectin emulsion, and 1% emamectin benzoate-9% imidacloprid soluble liquid agents.【Method】Sampled at different parts of the pine tree in layers. Analyzed residue dynamics in the tree using liquid chromatography-mass spectrometry (LC-MS). Quantitatively analyzed the translocation, distribution, and residue dynamics of the chemical within pine trees. Following trunk injection, inoculate the pines and design a secondary inoculation to simulate continuous nematode infestation; continuously monitor and record disease development to evaluate the chemical's long-term protective efficacy.【Result】Three trunk-injected agents effectively reached various parts of Pinus massoniana, with the main trunk showing the highest residue levels and branches less so. Residues generally lasted about three years, peaking in the first year, then declining. The 5% emamectin benzoate had the best transport and residue, maintaining a 24.609 mg/kg residue level after three years, and remained at a 37.50% control efficacy after a second inoculation. Abamectin showed rapid degradation, with no residue detected in top branches after three years, and only 12.50% efficacy after a second inoculation. The 1% emamectin benzoate-9% imidacloprid had lower nematode control, resulting in the earliest onset. Higher doses effectively increased residue levels, with 60 mL 5% emamectin benzoate reaching 33.900 mg/kg after one year, much higher than 30 mL 5% emamectin benzoate's 2.405 mg/kg. Injection methods had little effect on residue distribution at 1 and 2 a.【Conclusion】Three trunk-injected agents can be transported to all parts of the tree after injection. Compared with the other two, 5% emamectin benzoate has higher transport efficiency and residual amount, making it the preferred agent for long-term prevention and control of pine wilt disease. All three agents can effectively prevent pine wilt disease for a relatively long time after injection. The residual amount and control effect are still significant one or two years after injection, but the control effect decreases significantly three years after injection.