Research On Investigation Of Diseases And Insect Pests In Fraxinus Chinensis Roxb.in Nursery Land And The Chemical Prevention Of Hyptantria Cunea In Huimin County,Shandong Province

The nursery-grown plant is a basic element of the urban greening and a part of urban green landscape,so the demand for green seedlings in China will be stronger in the next period of time.But the ecosystem of artificial green woodland is relatively fragile,the development of diseases and insect pests is more serious,the most effective way to control the spread of seedling pests is to enhance the supervision and management of the nursery pests.The study focuses on the investigation and analysis of the ash nursery pest in Huimin County,Shandong Province.The measures to improve the seedling quality are putted forward through the actual investigation of the nurseries in Huimin County.In the paper,The method of setting the plot was introduced to the investigation of the diseases and insect pests of the ash nursery pest in Huimin County,Shandong Province.4400 acres ash nursery from the professional nursery stock companis was investigation by setting 170 plots;5650 acres ash nursery from the nursery stock cooperatives was investigation by setting 149 plots;1594 acres ash nursery from the Seedling families was investigation by setting 282 plots.The main conclusions are as follows:1)12 species of pests are found in nursery lands.In this investigation.there are 5 kinds of leaf-feeding insects,including:fall webworm(????),oriental moth(????),nettle grub(????),psilogramma menephron(????),psilgramma menephorn(????)and slug moth(????).4 kinds of stem borers include white cloudy spotted borer,ash beech bore,small carpenter moth,and holcocerus walker,3 kinds of trunk insects include drosicha corpulenta,lycorma delicatula and phenacoccus fraxinus Tang.Fraxinus chinensis includes fuliginosa,diaporthe medusaea and fraxinus chinensis.2)In this study,the nursery is divided into two categories: intensive management nursery and decentralized management of nurseriy.The incidence of pests and diseases under the intensive nurseris is relatively low: the total incidence of pests and diseases in the ash nursery of the nursery stock companies is only 0.19%,and the incidence of diseases and insect pests in the nursery of the stock cooperatives is 0.27%.The incidence of pests and diseases in the decentralized nurseris is relatively high: the total incidence of pests and diseases in the ash nursery of the rofessional growers is 0.75%,and the incidence of diseases and insect pests in the nursery of mall retails is 3.8%.The results of the survey are as follows: Intensive management is an effective way to reduce the disease and insect pests of nurseries in the whole region.In order to solve the problem that there are many insect pests in the nursery,the use of chemical control was investigation.The results of the experiment are as follows: the suitable dilution multiple of 2%·4000IU/?L alpha thuringiensis bacterial suspensionbacteria suspension is 1000-1500 times;the suitable dilution multiple of 0.3% matrine agent is 750-1000 times(active ingredient: 3-4mg/Kg);the suitable dilution multiple of 30.5% emamectinbenzoate chlorbenzuron suspending agent is 1250-1667 times(active ingredient: 122-244mg/Kg);the suitable dilution multiple of 20% diflubenzuron suspension is 1504-1717 times(active ingredient: 116.5-133mg/Kg).When the dilution multiple of alpha thuringiensis bacterial suspensionbacteria suspension is 1000-1500 times,the effective pest attenuation rate up to more than 98%.