Effects Of Fertilization, Firing And Climatic Factors On The Seed Yield And Quality Of Zoysia Japonica

The study was conducted to thoroughly research on the technologies of seed production of zoysiagrass (Zoysia japonica Stoud.) in Jiaozhou, Shandong province in 2004. The results indicated that:1. The low temperature and sunlight during 10-35 days before heading were facilitated to differentiation and development of spikelets (r= 0.9565). 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 conelation and significantly different. But the thousand seed weight (TSW) of zoysaigrass and accumulated temperatures was negative conelation, however TSW and sunlight hours was positive conelation (r=0.9466). The interplay of sunlight and temperature during 10-20 days after beading was sensitive to TSW of zoysiagrass (r=0.90).2. 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 3553 个/m, 3043个/m² and 789.81 kg/hm², 779.38 kg/ 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.3. The optimal harvest time was the 36^th days after peak anthesis 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.