| The study was conducted to thoroughly research on the reproduction characters and technologies of seed production of zoysiagrass (Zoysia japonica Stoud.) in Jiaozhou, Shandong province from 2001 to 2003. The results indicated that:1. The low temperature and sunlight during 15-40days before heading were facilitated to differentiation and development of spikelets (r= 0.89). And the seed setting percentage, seeds per spike of zoysiagrass and the accumulated temperatures and sunlight hours during 5 days before heading and 15 days after heading was positive correlation and significantly different. But the thousand seed weight (TSW) of zoysaigrass and accumulated temperatures was negative correlation, however TSW and sunlight hours was positive correlation (r=0.9466). The interplay of sunlight and temperature during 10-20 days after heading was sensitive to TSW of zoysiagrass (r=0.90).2. The seed production of zoysiagrass was controlled by last year rainfalls, rainfalls and sunlight hours from March to June in natural condition. Therefore, the seed production will be predict according to those climate data.3. The fertile tillers of zoysiagrass emerged from short shoots after fruit. The fertile tillers of 93.0% in seeding plots were emerged from stolons, and that of 70-80% in transplant plots were emerged from rhizomes. The age of tillers of zoysiagrass was mainly one year old, and the tillers of one year old in seeding and transplant plots were 92.65% and 96.78% in all tillers, respectively. Their tillers of two year old were 6.75% and 2.81% in all tillers, respectively.4. The tillers in transplant plots were heavier than in seeding plots, but the weight of fertile tillers were reverse to its tillers'(P<0.01). In reproduction allocation the spike was the heaviest, which dry weight was about 50mg. The second was leaf and stem. The spike from stolon was 57.63% in reproduction allocation of weight. Its proportion was slightly smaller than that of the spike from rhizome. The proportions of their stems and leafs were about 9.0% and 30.0%, respectively.5. The higher seed yield of zoysiagrass was obtained in the third year after established by transplanting and seeding. Their seed yields were over 844kg/hm2. However the seed yield in seeding plots was very lower (<22.5kg/hm2) in the second year(2002). And the seed yield of about 150kg/hm2 was obtained in transplant plots in 2002.6. The suitable rate of nitrogen fertilizer application could increase fertile tiller numbers and seed production. The rate of 30 kg N/hm2 (20 kg N/hm2 in autumn, 10 kg N/hm2 in spring) was the best. The fertile tiller numbers and seed yield in seeding and transplant plots were 3343 /m2 , 2941 /m2 and 844.50kg/hm2, 874.65kg/hm2. Further increase in N fertilizer rate decreased the fertile tiller numbers and seed yields. The spike length of zoysiagrass, spikelets per fertile tiller, seeds per fertile tiller, thousand seed weight and setting percentage were increased duo to N fertilizer applied. The dehydrogenase activity , acid phosphoesterase activity and seed vigor were improved by N fertilizer application.7. The optimal harvest time was the 36th days after peak anthesis (about June 15) in our experiment, and when the seed moisture content was 26%-28%. The fertile tiller numbers and seed yield of 'Haiqingl' zoysiagrass were higher than that of'Haiqing2' zoysiagrass (P<0.01). So the 'Haiqingl' zoysiagrass is prior to 'Haiqingl' for seed production.8. Irrigating according to weather and soil moisture content (field capacity 50%), the setting percentage and thousand seed weight were improved. The seed yield and acid phosphoesterase activity were significantly increased (P<0.01). Burning improved the seed yield and quality of zoysiagrass significantly. By contrast with no burning, the fertile tiller numbers/m2, seeds per fertile tiller, setting and seed yield were increased and the percentage of deaf and shriveled seeds was decreased in burning field. And the tillers and fertile tiller numbers increased significantly when sand...
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