Anthocyan contained in green leaf is closely related to the cup quality of SENCHA, especially the taste and the colour of liquor, and the more anthocyan in green leaf, the worse the cup quality of SENCHA.
The present investigation was undertaken to find a selection method of SENCHA quality as an aid of juvenile selection.
The correlation coefficient between the degree of anthocyan colouration of the first leaf of new shoot at nursery stage and that of same seedling at maturity was calculated. The correlation coef-ficients of 11 cross combinations for SENCHA were all positive and significant. Arithmetic mean of 11 cross combinations is 0.409, and those of each combination for black tea and KAMA-IRICHA were 0.555 and 0.566, respectively.
It seems that the correlation coefficients will be raised by improving the evaluation method of anthocyan colouration, for example, the colouration degree is exactly evaluated using the leaf of same stage after leaf opening, and then the juvenile selection by colour of young leaf will become a usefull selection method of SENCHA.
Furthermore, the definite tendency that the degree of anthocyan colouration at nursery stage is darker or lighter than that of same seedling at maturity could not be observed.

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To investigate the change of environment by the opening of new tea area in sloping land, the actual survey was done in the sloping tea fields of 27 prefectures opened from 1965 to 1973.
1. From 1965 to 1973, tea fields of over 1000 ha were increased every year in our country and 60% of them were sloping fields. The 90% of opened fields were smaller than 1 ha, although the larger ones than 10 ha were seen sometimes. In many cases, these fields were converted from thickets of assorted trees, have gradient of 5-10°, elevation of 200-300 m above the sea level, and are mostly facing south.
2. The opening methods of new tea area of 106 fields over 1 ha were surveyed. These fields were opened about 300 m above the sea level, and almost all of them were about 10 ha and opend by the logging of thickets of assorted trees. The expense for the opening of new tea area was about 230, 000 yen per 0.1 ha and area per a farmer was about 0.5 ha.
Arrangement of farm roads and overflows in the new opened area was relatively good, but farm roads were seldom paved and the drainage of fields where valleys were tilled up by the soil of hills were not enough. The varieties of tea in these fields were almost Yabukita, and the den-sity of planting in sloping tea fields was almost the same as the low tea fields.
3. About the soil conservation of opened tea fields, soil erosion of space between hedges in tea fields was well prevented by mulch, but the erosion of bank between two different sloping tea fields was severe and the landslide of ground where valleys were filled up with hill soils was very severe.
The opened tea fields were suffered from the cold, drought or wind because they were opened in relatively high elevation and the surrounding forest trees were logged. So the tea stand should be prevented from cold wind in winter, but the shelter hedges for the prevention from wind were made only in 40% of surveyed fields.
4. From the environment conservational point of view, the neighbouring environment was seen to be changed favorable by the opening of new tea area in the sloping land. Namely, the scope of tea fields was enlarged by the opening of corporation tea fields, and the mechanical cultivation of the tea fields and the transportation of machinery for the tea cultivation became easy by the improvement of farm roads. These facts show that the environment of these regions were improved by the opening of new tea area.
On the contrary, the soil erosion or landslide of tea fields occured not only in the tea fields, and the muddy water contaminated rivers and had a bad influence upon the river fishery. These tendencies show that the greatest care must be taken about soil conservation of opened new tea area for the environment conservation of that region.

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In order to improve the productivity of tea plant cultured in the field of mineral soil, the present experiments were undertaken to investigate the effects of underdrainage on the growth of young tea plants.
1. The general characteristics of the soil of tea field belonged to the yellow-brown mineral soil consisting of Lic-Lic-HC-Lic layers. That is, the first and second layers were composed of a little compact light clay of a dark or bright-brown in color, and the third one a heavy compact clay of a bright-brown in color.
2. Four kinds of underdrain were set up in the tea field of mineral soil. On comparing pH-values of the soil one meter apart from each underdrain with that of control plot, it was evident that the underdrainage was effective.The vigorous growth of tea plants was brought about by the underdrainage with the increase in plant age, but no difference was observed among four kinds of underdrain.
3. The effect of the distance from the underdrain upon the tea yield showed a negative in straight of first degree or a negative in curve of secondary degree, and the lower yields were produced with increasing in distance from underdrain.
4. Both the physical change and the three-phase distribution of the soils caused by the underdrainage favored the root development of tea plant.
5. From the results above mentioned, four meters from the underdrain was considered to be within the range of the underdrainage-effect on the tea field of mineral soil.

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For increasing the efficiency of irrigation and fertilization, the piping system of application of water and manure into the soil was investigated in the tea field.
In the piping system using plastic pipes with many small holes, these pipes were buried in the ground to a depth of 10cm from the soil surface and water or liquid manure was put into the soil by the pump. Put water or liquid manure extended triangular from the pipe to the 90cm depth soil.
It was thought that the optimum amount of irrigating water was 15mm or 20mm at the condition of soil moisture of pF 2.7 in general. In this method, the amonut of water for irrigation was 100 ton per hectare, it being half amount of sprinkler irrigation at the same condition of soil moisture.
Using this method, the yield of third crop was increased by the irrigation of water and the yield and green tea quality were improved in each crop by the application of liquid manure.

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Influences of nitrogen source and the culture concentration of nitrogen, phosphorus and potassium on the growth of tea plant, the constitution of amino acids of leaves and mineral elements of plant organs were investigated by sand culture method carried out for two years. The concentration of nitrogen (NH₄-N, NO₃-N), phosphorous and potassium were set to be 0, 25, 50 and 100 ppm, respectively. The results obtained were summarized as follows.
1) The tea plant cultured with 25 and 50 ppm of each mineral nutrient showed better growth, that with 100 ppm of each element exhibited excess damage, and that without each nutrient showed the respective deficiency symptom, especially enhanced one in the case of nitrogen. The tea plant supplied with NH₄-N as nitrogen source showed better growth than that with NO₃-N. The leaves cultured by NO₃-N showed chlorosis in any concentration.
2) As for the constitution of amino acids, the leaf supplied with no nitrogen contained small amount of each amino acid. In the case of NH₄-N, the higher the nitrogen concentration, the more the contents of theanine, arginine, serine, threonine and so on. On the contrary, in the case of NO₃-N, the contents of theanine, arginine, serine, etc. slightly increased according to the amount of nitrogen in the first year of the experiment, but remarkably reduced in the second year.
As for amino acids of leaf supplied with no phosphorus, a large amount of arginine accu-mulated in it. The higher the phosphrous concentration, the less the contents of arginine, serine and so on. The higher the potassium concentration, the more the serine content, but the other amino acids tended to decrease.
3) The mineral elements of each organ increased according to each mineral nutrient. The amount of total nitrogen was more abundant in each organ of the plant supplied with NH₄-N, and this increase rate was higher in the case of NH₄-N than that of NO₃-N. The manganese content was higher in the aerial part than the subterranean one of the plant supplied with NH₄-N, whereas it was higher in the subterranean part than the aerial one in the case of NO₃-N, and the content increased with the increase of the cocentration of supplied nitrogen. The aluminium content of each organ was higher in the tea plant supplied with NH₄-N. The iron content was also higher in each organ of the tea plant supplied with NH₄-N, especially in the root. Antagonism of potassium and zinc against NH₄-N, that of magnesium and manganese against potassium, and that of zinc against phosphorus were recognized, these trends being remarkable in the root.

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[in Japanese]

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[in Japanese]

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There is no enough data of investigation which elucidate the difference of chemical and physical make up in various kinds of green tea.
Gyokuro, Sen-cha, Kamairi-cha, Ban-cha and Hoji-cha of various grade were subjected to both chemical analysis and physical measurement.
Gyokuro and Sen-cha of high grade made from young shoots of the first flush were rich in amino acid, caffeine and total nitrogen, whereas Ban-cha and Hoji-cha made from coarser shoots were poor in above constituents.
Kamairi-cha of low grade was rich in tannin, while Gyokuro and Hoji-cha were poor.
Sen-cha and Kamairi-cha of high grade were rich in ascorbic acid, whereas Gyokuro and Hojicha were poor.
The content of phosphorus and kalium was high in Gyokuro and Sen-cha of high grade.
Gyokuro and Sen-cha of high grade were rich in dimethylsulfide, whereas Sen-cha of low grade and Ban-cha and Hoji-cha were especially rich in 2-methyl propanal which developed by heating, Gyokuro and Sen-cha of high grade were poor in this constituent.
Hunters a/b ratio value obtained by color difference meter showed higher minus in Gyokuro, comparativly low minus in Sen-cha and Kamairicha, and plus in Hoji-cha.

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