A new cultivar ‘Yumesuruga’ for green tea was developed from seedlings derived from the cross of ‘Okuhikari’ × ‘Yabukita’ at the Shizuoka Tea Experiment Station in 1986. The clone was selected by individual selection in 1993. It was evaluated for local adaptability and for a specific characteristics from 2002 to 2008. It was named ‘Yumesuruga’ and registered by The Plant Variety Protection System in 2012. And it was adopted as a recommended cultivar of Shizuoka prefecture in 2014.
The budding time of ‘Yumesuruga’ is slightly later than that of ‘Yabukita’. The shape of plant is medium type and the vigor of plant is very strong. It is middle resistant to cold damage in midwinter. And it is weak resistant to tea anthracnose (Colletotrichum theae-sinensis (Miyake) Yamamoto) and fairly resistant to tea gray blight (Pestalotiopsis longiseta (Spegazzini) Dai & Kobayashi), tea brown blight (Glomerella cingulata (Stoneman) Spaulding & Schrenk ) and middle resistant to tea bacterial shoot blight (Pseudomonas syringae pv . theae (Hori 1945) Young, Dye & Wilkie 1978). The yield of new leaves of this cultivar is higher than that of ‘Yabukita’.
The quality of the unrefined tea of ‘Yumesuruga’ is very good, especially for the color of made tea and liquor are fresh green with bright color. And the taste is mild.
‘Yumesuruga’ adapts itself to any tea cultivated region in Shizuoka prefecture. And it is cost effective for the tea factory management to combine several cultivars which have different harvesting time.

In this study, we paid attention to free amino acid content, which is one of the indices of tea quality, and aimed to develop a shading method to produce tea leaves having high free amino acid content without decreasing the yield. As a result, we found that a two-stage shading method, comprised of 85% shading for 9 days and then 98% shading for 5 days, is effective for this purpose in the ‘Yabukita’ tea cultivar.
This method makes it possible to raise the free amino acid level provided from a unit area of a tea plantation. This two-stage shading method also increased the free amino acid content of the ‘Mieuejima’ and ‘Okumidori’ tea cultivars. However, the change in individual components differed according to the tea variety and the leaf stage when shading started, so the choice of shading method will likely depend on its purpose.

The insecticide susceptibility of bagworm moths, Eumeta minuscula Butler and Mahasena aurea (Butler) on tea leaves was evaluated at 25℃ under a 15L- 9D photoperiod. Among the 18 insecticides tested on second or third-instar larvae using the leaf-dipping method, chlorantraniliprole and flubendiamide were more toxic to the E. minuscula. The damage degree of tea leaves by E. minuscula larvae showed 0 when applied with cartap and fenpropathrin. Among the 15 insecticides tested on second or third-instar larvae using the leaf-dipping method, flubendiamide, emamectin benzoate, spinetoram, chlorfenapyr, and fluxametamide caused high mortality in the M. aurea. The application of methomyl, spinosad, flubendiamide, and fluxametamide reduced the degree of damage to the tea leaves by M. aurea.