The Control Effect of Prevention and Control Technology Combination against Southern Rice Black-Streaked Dwarf Disease

Objective] This study aimed to explore a better prevention and control technology combination against southern rice black-streaked dwarf disease. [Method] The control effects of seed dressing, antiviral agents and fly net along with 25%pymetrozine against southern rice black streaked dwarf disease were determined. [Result] When the seeds were dressed with 60% imidacloprid （FS, 2 g a.i./kg）, and the rice seedlings were sprayed once with 25% pymetrozine （WP, 360 g/hm2） 10 d before the transplanting and sprayed twice with 30% Dufulin （WP, 800×） at three-leaf stage and 7 d after the transplanting respectively, the control efficiency reached 88.05%. When fly net and pesticides were applied simultaneously, the fly net was lifted and 25% pymetrozine （WP） was spayed once on the rice seedlings at six-leaf stage and the seedlings were hardened for 3 d and sprayed once with 25%pymetrozine （WP） 10 d after the transplanting, the control efficiency reached 80.50%. [Conclusion] Seed dressing or applying antiviral agents alone can not better control diseases. The southern rice black-streaked dwarf disease can be better con-trol ed by seed dressing, along with spraying of planthopper-kil ing agents at two-leaf stage, 3 d before the transplanting and 7 d after the transplanting, respectively. If condition al ow, fly net can be instal ed to achieve better control effect.

Prevalence Characteristics of Rice Black-streaked Dwarf Virus Disease and Continuous Control Strategies

Through summarizing the prevalence characteristics of rice black-streaked dwarf virus disease(RBSDVD)in Linyi City of Shandong Province,this paper analyzed its prevalence is related to changes in farming and cultivation systems,the increase in the population of venomous Laodelphax striatellus Fallén and its own migration and spread,the poor disease resistance of cultivated varieties,and inadequate time of prevention and control.Besides,based on the practice of local control,it came up with some comprehensive control measures including strengthening monitoring,early warning and forecasting,planting resistant(tolerant)rice varieties according to local conditions,appropriately delaying the sowing(planting)period,supplemented by insect nets to cover seedlings,and making scientific use of chemical control.It is expected to provide a reference for the prevention and control of RBSDVD.

Disaster Prevention and Mitigation Technologies of Rice Virus Diseases Spread by Small Brown Planthopper (SBPH)

Rice stripe virus disease （RSVD） and rice black-streaked dwarf virus disease （RBSDVD） are two epidemic diseases in Yancheng City, Jiangsu Province in the last decade. The authors investigated the disaster regularity, prevention and control technology of RSVD and RBSDVD systematically. The occurrence and virus transmission of SBPH and disaster regularity of virus diseases were studied; the resistance of some rice varieties was cleared; the effects of physical and agricultural measures such as insect net blocking, appropriate late sowing and plowing on controlling occurrence and virus transmission of SBPH were figured out; a hatch of chemical agents were screened, providing efficient and harmless pesticides for effective control against SBPH and prevention against virus diseases. A set of disaster control and mitigation technologies was proposed in this paper, which was practical, sustainable, and easy to operate for the local planting patterns.