基于负压通风的多杀霉素粉剂实仓喷施工艺研究

Field trial on distribution of spinosad powder in grain bulk applied by vacuum ventila-tion in warehouse

多杀霉素是控制储粮害虫的有效杀虫剂,为了加快其在实仓中简便、高效应用,研究基于负压通风的多杀霉素粉剂在实仓中的喷施工艺。通过分析风机通风参数、施药均匀性,比较基于负压通风和表面拌粮两种施药工艺对多杀霉素在粮仓中穿透深度和对4种主要储粮害虫的致死作用。结果表明:在负压通风的风机平均风速为7.57 m/s、30 min内完成仓容1329 t的整仓通风条件下的多杀霉素粮堆表层喷施,施药量30 kg;与表面拌粮施药工艺相比,基于负压通风喷施工艺的粉剂穿透深度普遍达45 cm,甚至可达105 cm,更易穿透粮堆;施药能有效控制虫笼中长角扁谷盗、谷蠹、玉米象和赤拟谷盗4种储粮害虫成虫,21 d时校正死亡率最高可达92.4%。基于负压通风的多杀霉素粉剂喷施工艺具有操作简便、人工成本低、防虫效果好等优势,具有实仓应用可行性,研究结果为实仓多杀霉素防治储粮害虫提供了技术支撑。

Spinosad that has the advantages of high insecticidal efficiency,safety to non-target organisms,and low residue is a secondary metabolite produced by Saccharopolyspora spinosa.It is an effective insecticide to control stored grain pests.At present,the application of spinosad in warehouse mainly adopts the process of insecticide mixed with surface grain(mixed process),but it is time-consuming and labor-intensive.Therefore,the application of spinosad is restricted in warehouse.In order to speed up the simple and efficient application of spinosad in warehouse,this work studied the spraying process of spinosad powder in warehouse based on the vacuum ventilation(spraying process)by analyzing the ventilation parameters,the homogenization and penetration depth of spinosad in warehouse,and the mortality of four kinds of main stored grain pests(Cryptolestes pusillus,Rhyzopertha dominica,Sitophilus zeamais and Tribolium castane um).The results showed that the average wind speed of the fan was 7.57 m/s,and the whole warehouse with a storage capacity of 1329 tons could be sprayed by spinosad within 30 minutes using spraying process.The total dosage of spinosad was 30 kg.The weights of spinosad powder in the disks near the in-secticide spray points(A,G and K)were higher than the others.Otherwise,the spinosad powder was e-venly distributed elsewhere on the surface.Compared to the mixed process,the penetration depth of spi-nosad using spraying process can be generally up to 45 cm and even reached 105 cm,which indicated that the spraying process was easier to penetrate grain pile for spinosad powder.At 7 days,the corrected mortal-ity of four kinds of pests in the warehouse using spraying process was lower than that of mixed process.However,the corrected mortality of Sitophilus zeamais and Tribolium castaneum,higher than 89.5%,had no significant difference between the two warehouses using mixed process and spraying process at 21 days.In order to further optimize the application process based on vacuum ventilation and improve the homogeni-zation distribution of the spinosad in horizontal and vertical planes,factors such as fan power,insecticide spray point setting,ambient temperature and humidity,and the size of warehouse should be taken into ac-count.Since the advantages of simple operation,low labor cost and promising effect of pest control,it is feasible to apply spinosad by vacuum ventilation.This study laid a foundation for further application of spi-nosad in warehouse to control stored grain pests.