[in Japanese]

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1. These studies were performed to find out the limited time of the last plucking of the tea plant in cold locality. The last plucking was made several times from the beginning of July to the end of August.
2. The processes of the growth of new shoots after the last plucking were observed physio-logically and morphologically. It was proved that the later the plucking time, the more inferior the maturity of shoots and the weaker the cold resistance.
These tendencies were remarkable in the tea plant plucked after the middle of August.
3. The same results were obtained on the growth of the new shoots in the first cropping season of next year.
These tendencies were also remarkable in the tea plant plucked after the middle of August of the previous year.
4. Therefore, the limited time of the last plucking of the tea plant in cold locality was considered to be the beginning of August.

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1. These studies were performed to find out the most suitable time and degree of depth of the spring trimming before the first plucking.
2. The plucking time of the first crop was not controlled by the spring trimming time in this locality.
3. The trimming in April reduced the number of new shoots and the yield. The trimming at the beginning of March brought the cold damage to the leaves and buds frequently. So the most suitable time of the spring trimming was considered to be about 20th March.
4. The most suitable depth of the spring trimming was considered to be 2-3 cm over the plucking surface of the second crop of the previous year. Too light trimming reduced the number of new shoots and the yield, and too severe trimming also reduced the weight of new shoots and the yield.

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1. These studies were performed to find out the influences of the plucking time of the first crop and three different dispositions after each plucking upon the yield and quality. These dispositions are noninterference, trimming on 10 days after plucking of the first crop and plucking of late shoots.
2. As to the plucking of the first crop, it was proved that about 60-65% of banjhi shoots to the total ones showed the most effective results on the yield and quality.
3. The deterioration in the quality of the second crop was brought about by noninterference after the plucking of the first crop, owing to the uneven ripening of the new shoots of the second crop.
4. In the year when the lower class tea was wanted in the market, the plucking of late shoots between the first and the second crop season brought about the advantageous results using tea var. "Yabukita", but not advantageous using "Sayamamidori".

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[in Japanese]

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In this study, the amount and placement of crotonylidene diurea (CDU) manuring before tea planting were investigated in comparison with those of ammonium sulphate. The results obtained are summarized as follows.
1. In autumn planting, the CDU manuring before planting showed little better growth than the divided manuring of ammonium sulphate. The difference of growth by the amount of CDU manuring was not evident.
2. In spring planting, it was confirmed that the effect of the manuring of CDU before planting was better than that of the divided manuring of ammonium sulphate, and the additional manuring between spring and autumn could be omitted, and the suitable amount of nitrogen was 20 kg per 10 a.
3. Considering the result that was examined about the relationship between the amount of manuring and electric conductivity of soil solution, the manuring of CDU had shown low value of electric conductivity at first stage, but a high value was indicated according to decomposition process.
It was feared that the large quantity of manuring of CDU would cause a density trouble.
A high value of electric conductivity in soil solution was shown in manuring of ammonium sulphate, so a small quantity (about 10 kg/10 a) of its manuring caused a density trouble and tea plants withered.
4. It seemed that the manuring of CDU caused a trouble when tea plants were kept contact wtih CDU, but otherwise it did not. The deep placement of ammonium sulphate withered the plants, and the placement around the root prevented the growth of plants.

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It is commonly estimated that green tea produced in the Southern Kyushu area show brownish green and turns to dark brown easily during storage and also its liquor has strong bitterness.
To better the qualities of the Southern Kyushu green tea, the improvement of the primary heating tea roller (capacity : 50 kg of fresh leaves) was studied.
The testing machines were reformed from two different commercial machines. Main reformed points are as follows :
1. Power of blower fixed on furnace was enhanced from 1 ps. to 2 ps., so volume of hot wind was increased to 3 times higher than that of ordinary machine (37-45m³/min).
2. Leg (part 1 in Fig. 1) of rolling hand was made 1 cm longer than that of ordinary leg and power of spring (part 2) of rolling hand was strengthened with three springs or two thick springs.
3. Shape of rolling hand was reformed as shown in picture 1. Arc of bottom of rolling hand (part 3)was changed to larger circular arc and wave (part 4) of rolling hand was reformed to deeper curve than those of ordinary one.
4. "Duke" (front inside wall of the drum, part 5), on which steamed tea leaves were rolled by rolling hand, was lined from the bottom to the front of drum, therefore, distance from center to front wall became 1 cm shorter than that to back wall.
Green tea made by improved machine showed light-green color and its liquor changed to mild taste owing to diminished "stuffiness" and decreased "bitterness".
Also the period of primary heating and rolling by new reformed machine reduced by about three-fourth of that by ordinary one.

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For the purpose of making clear the limited moisture content to maintain the quality of green tea and the relative humidity (partial vapor pressure) in a packing container which are the important factors to presume the damp-proofing property of packing material which is necessary to maintain the quality during the circulation period of a packaged green tea, the methods of measurement thereof were studied and the following results were obtained;
1. It was proved that the limited moisture content to maintain the quality of green tea is 6.5, 6.0, 5.0 and 4.5% each at a temperature of 10, 20, 27 and 35°C during 30 days storage.
2. Hygroscopic isothermal characteristics at a temperature of 27+1°C and green tea moisture content of about 3.9% were obtained, from which it was made clear that the relative humidity (partial vapor pressure) developed by green tea with moisture content of 3.0-5.O% within a packing container ranged from about 20 to 40/% R.H.
3. At a temperature of 25±2°C, relative humidity (partial vapor pressure) produced by green tea different each other in moisture content was measured with a hygrometer and a high degree (r=0.985) of correlation was observed among them, leading to a regression formula of y=8.55x-3.18. The values calculated there-from were compared with the values obtained from the hygroscopic isothermal characteristics and they were found to be almost coincident with each other within the range of green tea moisture content from 3.0 to 5.5%, for which. reason the said regression formula is seemed to be fully applicable.

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[in Japanese]

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