Abstract
The effects of chitosan application on the yield of the first crop of tea cultivars 'Asatuyu' and 'Yabukita' were investigated for 2 years from 2004 to 2005. In 2002 and 2003, yields of the first crop and autumn crop among plots were examined without chitosan application. The yield differences among plots were not significant. In 2004 and 2005, a chitosan solution was applied to tea plants by foliar spray of 2000 L ha-1 in spring each year. In 'Asatuyu', the yield of the first crop before chitosan treatment was slightly superior to that of control plot, and that after chitosan treatment was significantly higher than that of the control plot. In 'Yabukita', the yield of the first crop before the chitosan treatment was slightly inferior to that of the control plot, and that after chitosan treatment was similar to that of the control plot. There was a negative relationship between the autumn crop yield and the first crop yield in the next spring in both cultivars. These negative relationships tend to be improved slightly by chitosan application. These results suggested that chitosan application slightly increased the yield of the first crop.
