Super early hybrid rice Luliangyou 996 was the materials for this experiment. This paper focused on the influences of different nitrogen rates on blast resistance and grain yield. Studies suggested that with the increase of nitrogen rate,there were no distinct changes in the sick grain rate and sickness index, but the fifth grade of panicle blast rate rose gradually. When the nitrogen was too much（270 kg/hm^2）, the sick grain rate and sickness index were the highest. The yield rose along with the addition of nitrogen if the amount of applied nitrogen was within the range of 0 to 180 kg/hm^2, and the yield would decrease with the addition of nitrogen if the amount of applied nitrogen was over 180 kg/hm^2. Considering the sickness, output and economic benefit of rice, it is better to applied 90 to 135 kg/hm^2 of nitrogen for Luliangyou 996.
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.
