The author has previously carried out field surveys and analyses of field samples and found that the manganese content in apple trees varies with the kind of rootstocks and soil conditions and also that the manganese content is closely related to the incidence and the degree of the physiological disorder, rough bark. In order to further substantiate this relationship, 2-year-old seedlings of Rails apple that had been grafted on Malus sieboldii (Ralls/sieboldii for brevity) or on Malus pruniforia (Rails/pruniforia) were prepared, and these were grown by sand culture solutions containing manganese in different concentrations (0.5, 30 and 45ppm) from the beginning of May to the middle of October, after which they were analyzed for manganese. The results were examined in relation to the occurrence of the disorder. From this, the following points seem to become clear.

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The insects visiting apple flower were investigated at Kuroiso Branch of the Tochigi Agricultural Experiment Station during May 11 -May 17 in 1965. The results obtained are summarized as follows:
1) The weather conditions during the period of observation were favorable for the flying activities of insect visitors, without remarkable deviation of air temperature and prevalence of fine and calm days.
2) For the reason of abnormal low temperature in the early spring, the blooming period of all varieties used in this study delayed about 10 days than in an average year, though the amount of blossoms was relatively abundant.
3) The insect visitors collected in this work were mostly hymenopterous and dipterous insects. Total individual number of Hymenoptera is 2018, that is, 8.3 times as large as that of Diptera. Iyymenopterous visitors belong to 45 species (5 families, 12 genera), while dipterous visitors belong to 17 species (5 families, 14 genera).
4) The important visitors in Hymenoptera are arranged in the descending order as follows:
Andrena opacifovea, Apis mellifera (honey bee), A. kaguya, Lasioglossum trispine, L. subfamiliare-complex, L. sp. ad. discrepans, A. sasakii, A. hebes, A. dentata, and Xylocopa appendiculata cirumvolans (cf. Table 3).
The most numerous visitor of Diptera is Tubiferacerealis, then Bibio rufiventris is next, and other species are very scarce in number (cf. Table 4).
5) Four species of Andrenid bees, A. opacifovea, A. sasakii, A. dentata and A. hebes are the mediumsized bees, as large as or slightly smaller than honey bee. Their total numbers reach 872 and occupying 43.2% of Hymenoptera. Further their visiting activities are very rapid and vigorous (=very quick and restless movements on flowers). Therefore they seem to be the most efficient visitors.
6) Halictid bees seem to be inferior to Andrenid bees in pollinating efficiency because of smaller sizes, though they are numerous and their visiting activities are rapid and vigorous.\
7) Both Tubifera cerealis and Bibio rufiventris are the dominant visitors in Diptera, but Bibio rufiventris is supposedly not an important pollinator, judging from their very sluggish activities. On the other hand, Tubifera cerealis is relatively active, so that it seems to be the most important pollinator among Diptera.

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This study was conducted in order to investigate the parasitism of Macrocentrus ancylvorus Rohwer imported from Canada as an agent for biological control of the Oriental Fruit Moth. The major results obtained are summarized as follows.
1. 313 male and 345 female adults of Macrocentrus were obtained from imported material at Fukushima Horticultural Experiment Station under insectary condition.
2. Satisfactory parasitization of host larvae was obtained by releasing parasites into a rearing cage in which pieces of apple which harbour host larvae are hooked on a wire. A good deal of parasitization was also obtained by exposing infested tender twigs of peach in a rearing cage to the oviposition of parasite.
3. Host larvae were exposed to the oviposition of parasite for about 44 hours in rearing the first generation after importation and for 24 hours in rearing the second generation. It was found that exposure for 24 hours was enough.
4. The duration for development for the first generation after importation lasted 21 to 28 days and that for the second generation 33.5 to 66.5 days.
5. More females emerged both in the first and the second generations, the ratio of female to male being 1.1 for the first and 1.7 for the second generation.

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The possibility of practical use of one year stored pear pollens for the artificial pollination of Nijisseiki pear was investigated in 1962-1965.
1. At the optimum storage condition in a home use electric refrigerator one year stored pear pollens of three varieties gave a germination of 80.3% for Chojuro, 67.4% for Okusankichi, and 85.0% for Yagumo, respectively. They were 5-10% lower than the germination rate of freshly collected pollens in the respective varieties.
2. As the result of artificial pollination of stored pollens in the field, more than 80% of the flowers developed into fruit having average 7 seeds per fruit when the pollens had more than 30% of germination rate. Also, there found no differences between stored and freshly collected pollens in the rate of fruit set, fruit development, and quality after harvest. It seemd that there was no trouble to use one year stored pollens in practical Nijisseiki pear culture.
3. It was recognizied that one year stored pollens collected from vigorous tree gave a germination of more than 70% when they were put into the refrigerator within 24 hours after collected and were kept at 5°C and 30-50% relative humidity.

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Oleification has been known as a practice in anointing the eye of the intact fig with olive oil in order to accelerate its maturity since the 3 rd Century, B. C. in Greece (Condit 1947).
There are some unknown problems, however, which we do need to clarify the reason why and how the practice of oleification would stimulate its ripening.
This report is the results of some experiments to acertain the effect of different oils and time of application in hastening the maturity of the figs.
Materials were used the breba of Masui Dauphine fig.
1. Oleification should be undertaken to a very limited period when the fruit attained about 34mm in width at the end of period II of the growth. At that time the color of the fruit skin changed from greenish to yellowish, a part of the eye swelled, and the color of the eye and fruitlets in the receptacle changed from light pink to reddish pink.
2. The application of some vegetable oils to the eye of the fig stimulate the ripening of the fruit. In a day or two the treated fruits began to increase in size and in six days they reached full color and maturity, while untreated figs remain green and hard. The treated figs were equal in size, color, and contents of sugar and acid to those allowed to mature naturally.
3. The treatment of animal oil also stimulate the ripening of the fruit, but the effect was less than that of vegetable oils. Treated figs matured 8 days after treatment.
45 The effect of mineral oil was not constant and inferior to that of vegetable oils and animal oil. No effect of liquid paraffin was observed.

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The environmental conditions of citrus orchards infested by citrus flat-headed borer, Agrilus auriventris, which is one of the most destructive insect pests of the citrus, were studied during the time of outbreak in Nagasaki Prefecture, 1961-1963.
Two hundred and twelve orchards including 5, 551 citrus trees under the various degree of infestation by the borer were surveyed. The degree of infestation and some environmental factors such as the age of trees, species or variety of citrus, climatic conditions, methods of management and the infestation of gammosis were examined in each orchard.
This insect attacked older trees than younger one, especially more than 50 years old. In Satsuma orange, the percentage of infested trees were not so much, but the attacked trees fell into dye frequently. On the other hand, Natsudaidai and other species of orange and lime trees were more parasitized than Satsuma Orange. But the percentage of dead trees were not so much.
In the orchards, which were suffered by cold weather, draught or abnormal defoliation, the more severe damages by citrus flat-headed borer were observed.
The positive correlation between the infestation of gammosis and the damage of flat-headed borer was recognized. But the gammosis was not assumed as the necessity for infestation of borer.

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1. Leaf fall of Satsuma orange trees (Citrus unshu) as induced by the sulfur dioxide fumigation particulary after the sulfur containing sprays such as lime sulfur was studied with 2-year-old potted plants. Fumigation was conducted with 0, 1, and 5ppm of sulfur dioxide for 3 weeks 2 hours each day, in December.
2. Sodium sulfide (0.4% water solution) had the worst influence on leaf fall, and it was followed by wettable sulfur (0.4% water suspension). The higher the concentration of lime sulfur, the more increased the leaf fall with the fumigation of higher concentration of sulfur dioxide. Namely, it is suggested that spray of lime sulfur from autumn to winter with practical concentration would be safety unless the sulfur dioxide concentration be not markedly high.
3. Kinetin (20ppm in 20% ethanol solution) had no effect to prevent the leaf fall due to sulfur dioxide fumigation in winter.
4. Increase of sulfur content of leaves as indication of infiltration of sprays was generally low, though in the lime sulfur spray of Be 1.4° was the highest. Sodium was the highest in the sodium sulfide spray among the treatment, but sulfur suffered no change in this spray. Therefore, the promotion of leaf fall due to sulfur containing sprayss with sulfur deoxide fumigation would be caused by infiltration of sprays, but not be always by sulfur.

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The present studies were carried out to ascertain the influence of the application of nucleic acid and antimetabolites of nucleic acid on the growth and the flower formation of tomato plants.
Spraying with nucleic acid and antimetabolites of nucleic acid was begun when the cotyledon expanded fully and repeated 10 times at 3-day-intervals.
1. Effect of application of DNA and RNA on the vegetative and reproductive processes.
Plants were sprayed with 200, 1, 000 and 3, 000 ppm solution of DNA and RNA decomposed by autoclaving.
All concentrations of DNA and the lower concentrations of RNA sprays failed to induce any effect on the plant growth and the flower formation. High concentration of RNA spray increased the number of flowers.
2. Effect of application of guanine, uracil, uridine and uridylic acid on the vegetative and reproductive processes.
Plants were sprayed with solution of guanine, uracil, uridine and uridylic acid at 200, 1, 000 and 3, 000ppm.
All concentrations of guanine, uridine and uridylic acid sprays failed to induce any effect on the plant growth and the flower formation. High concentration of uracil spray increased the number of flowers.
3. Effect of application of 8-azaguanine and thiouracil on the vegetative and reproductive processes.
Plants were sprayed with solution of 8-azaguanine at 5×10^-4 and 2×10^-3M and thiouracil at 5×10^-5, 2×10^-4, 4×10^-4 and 6×10^-4M.
High concentration of 8-azaguanine and thiouracil spray restricted the plant growth, being follwed by the retardation of the flower bud differentiation, the increase in the number of leaves to the first inflorescence and the decrease in the number of flowers with the retardation of their development.
4. Effect of application of 5-bromouracil and ethionine on the vegetative and reproductive processes.
Seedlings were sprayed with solution of 5-bromouracil at 5×10^-4 and 2×10^-3M and ethionine at 5×10^-4 and 10^-3M.
High concentration of 5-bromouracil and ethionine spray restricted the plant growth, but failed to induce any effect on the flower formation.
5. Effect of application of acriflavin, mitomycine and chloramphenicol on the vegetative and reproductive processes.
Plants were sprayed with solution of acriflavin, mitomycine and chloramphenicol at 1, 10 and 50ppm.
The higher the concentration of acriflavin, mitomycine and chloramphenicol solution, the weaker the plant growth, the later the flower bud differentiation, resulting in the increase in the number of leaves to the first inflorescence, and in the less number of flowers.
6. Role of nucleic acid on the flower formation.
Applications of nucleic acid increased the number of flowers, and applications of antimetabolites of nucleic acid retarded the flower formation.
From the present results it may be suggested that the increase of nucleic acid in the apical part was an important factor for the induction of flower bud in the tomato plant.

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The experiments were conducted to study the fertilization processes and the development of proembryo in the artificially pollinated flowers of the tomato plants grown under the condition of 20°C constant, and to observe the abnormalities of ovules caused by high temperature of 40°C for four hours.
Pollen grains began to germinate three hours after pollination on the stigma. Fertilization took place 18 hours in the fastest one and 24-30 hours in the majority of ovules after pollination. Two-, four-, and eight-nucleate endosperm stages were observed 48, 72, and 96 hours after pollination, respectively, in the endosperm which showed the cellular type in the early formative stage. Two-, and four-celled proembryo were observed 96, and 120 hours after pollination, respectively. Proembryo was consisted of more than ten cells 196 hours after pollination.
The ovules which had been treated with high temperature 18 hours after pollination aborted. This might be attributed to the retardation or the stoppage of pollen tube elongation by high temperature.
In the ovules treated 24-96 hours after pollination, degeneration of endosperm was observed. In that case it was found that cytoplasm and nucleus were deeply stained or their contents were empty. In a few ovules the retardation of proembryo development was observed. In the ovules treated 120 hours after pollination, however, the abnormalities of the ovules were hardly observed.

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1. From 1961 to 1965, the author carried out an investigation on lettuce planting throughout the year, using varieties Great Lakes 366, Great Lakes 54 and Imperial 847, and observed their ecological adaptation.
2. The above investigation suggests that in Okayama district it is impossible to grow crisp varieties such as Great Lakes during April to August because of high temperature inducing early flower bud formation. From the view point of quality and harvesting time, the time of sowing in spring will be limitted by the middle of March.
3. The proper time for sowing in late summer is very short and varies with the year around August 20, although lettuce culture sowed in late August or early September was successful under the condition covered with vinyl film.
4. Winter culture in the field condition was also possible in this district by sowing in late September nor early October.
5. In the lettuce culture under green house without heating, the sowing should be done between late September and early November, because they will be injured with high temperature during the growing period.
6. Large and well heading lettuces were harvested from spring or green house culture, whereas poor quality, small and loose heading lettuces were got from late summer culture.
7. It was found that there was a correlation between the index of w₁/W or w₂/W and the mean temperature during the growing period. (w₁; the weight of outer 10 leaves of the heading part. w₂; the weight of inner 10 leaves of the heading part. W; the total weight of the heading part). In the former, negative correlation was found and in the latter positive correlation was found.
8. Within the range of temperature that allows the growth of the lettuce, it was found that below 17-18°C the higher the temperature during the growth being the larger the mean weight of a leaf, but the temperature exceeded that the reverse relation was observed.
9. Flower bud formation is ready to occur above 20°C in the growing season.
10. The lettuces grown in warm temperature tend to have long stems and flat form in the head, while those grown in cool temperature have short stems and glovular forms.
11. The lettuces grown in winter season and harvested in cool season have high sugar contents and high osmotic pressures, while those grown in warm season have low values of them.
12. Sugar content and osmotic pressure of the outer leaves were higher than those of the heading part. However, it is observed that those values in the outer leaves of the head were lower and become higher in the inner leaves of the head.
13. It is very interested to note that concentric circle lines in the values of sugar content and osmotic pressure were found within a leaf. The highest and isometric value was recorded in a line along the margin of the leaf, and then the values gradually decreased in the inner part of the leaf. These values in the outer leaves and inner leaves varied remarkably.
14. Heat summation from seedling to flower bud formation was about 1, 700°C in Great Lakes, and varied greatly with season.

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This paper describes the properties germination inhibitor in onion juice and its inhibiting mechanism.
1. Germination inhibitor was found in ether extracts obtained from onion juice. This was soluble in organic solvents, insoluble in water. This substance had Rf value of 0.81.0 with isopropanol-ammonia-water (1.0: 1: 1v/v) using strips of Toyo Roshi No. 51.
A large amount of inhibitor was found in rest bulbs as compared with sprouted one. Ohshu variety having a deep and long rest had less amount of inhibitor than Senshu-ki variety having a moderate rest.
These results suggested that the germination inhibitor in onion juice was not considered to be a main factor in connection with rest phenomenon of bulbs.
2. This substance was identified as allylsulfide group by ultra-violet spectrum, Rf value and special odor. Microchemical observation showed that the inhibitor was accumulated with bulb thickening, reached a maximum peak at harvest time and then decreased with sprouting, and that at harvest time higher concentrations of the inhibitor were found in neck and outer part of bulb.
3. The inhibition of germination with ether extracts was recovered to some extent by addition of 10^-1 and 10^-3 mole cysteine solution. These facts suggest that allylsulfide may inhibit the activity of the sulfhydryl enzymes. Consequently germination inhibitor could be a inbibitor of sulphydryl enzyme.

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The present studies are designed to elucidate the effect of soil and fertilizer on the pithy tissue formation.
i) The effect of the exchangeable base supply on the growth and the pithy tissue formation.
In this experiment, quarternary diluvial clay loam had about 13m.e. of exchange capacity and about 2.5m. e, of exchangeable base. The value for exchangeable base supply was obtained by subtracting the exchangeable base from exchange capacity. The rates of base supply were, namely, 75, 42. 5, 37.5, 32.5, and 17.5 per cent of the value as obtained above. The rate of root growth increased and the degree of pithiness decreased in proportion to the amount of cation supply, but in the case of a high rate of magnesium in total exchangeable cation, the thickening growth of roots is inversely related to the amount of magnesium supply and the occurrence of pithy tissue is relatively prevented. However, it is necessary for us to establish more successful methods.
ii) The effect of soil conditioner, polyvinyl alcohol (PVA), on the growth and the pithy tissue formation.
The rate of PVA application in the soil ranges from 0 to 1.6 per cent (w/w). The clay loam soil treated with PVA forms completely stable aggregates at the rate of 0.8 per cent. The relationships between the growth or the degree of pithiness and the rate of aggregate formation or the rate of PVA application are as follows:
Positive correlation{Rate of PVA application or of aggregates formation versus root growth and degree of pithiness
Negative correlation{Rete of PVA application or of aggregates formation versus leaf weight, T/R ratio, and root length
From these relationships, the occurrence of pithy tissue may be ascribed to the fact that the accumu-lation of assimilates or nutritives into the fresh root lags behind the abrupt thickening growth.
iii) The effect of three element supply during the period of rapid thickening growth on the pithiness.
The concentration of elements in the nutrient solution of cultural plot was as follows.
Nitrogen 126ppm. Phosphorus 62ppm. and Potassium 117ppm.
In the treatment plots the concentration of one of the three elements was doubled.
In the plot given double amount of nitrogen, the plant growth was checked. It may be suggest that there was a toxic effect of ammonium sulfate added to double the amount of nitrogen. With regard to the degree of pithiness there was no significant difference among the four test plots.
iv) The effect of foliage spray of urea on the growth and the pithy tissue formation.
Urea was contained in foliage spray solution at the rate of one per cent. Treatment is recommended to be made after the unfolding of four leaves. The urea spray tended to increase the root growth, but the degree of pithiness became slightly lower. There was, therefore, no significant difference with regard to the latter character between the control plot and the urea spray one.

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1. In Japanese maple, Acer palmatum Thunb. var. palmatum (Thunb.), ordinary stem-wood grafting is rarely successful when the shoots of the previous year are used as scion, whereas IHARA and TAMARI (1961) obtained satisfactory results by green wood grafting using the shoots of the current year as scion and stock.
2. To elucidate the cause of the failure in grafting, the effect of temperature on the callus formation was studied with scions of two-year-old seedlings (wild strain) kept on agar media. Graftings were made in different seasons. At the same time, the formation of joining tissues between the scion of a garden variety′Nomura′and the stock of the wild strain was observed for three weeks at different temperatures and different seasons.
3. Little callus formation was observed on the cut surface of scions at low temperatures under 15 °C, while the callus formation was fairly good at 20°C and over, culminating at 30°C. In grafted samples, the. joining tissue scarcely developed under 15°C, while good development was observed at 20°C and 25°C. Most of the scions were, however, covered by moulds and died when incubated at 30°C. The effect of temperature was thus similar in both cases.
4. The younger the age of tissue the better the formation of callus. However, the scions taken from the stem of the previous year formed a considerable amount of callus, which seemed sufficient for successful graft-union.
5. Though good callus formation was observedd at 30°C throughout the year, slightly more callus tissues were formed during the rest period (Jan.-Mar.) than in the growing season (May-Jul.). The graft samples incubated at 2530°C. also resulted in good graft-union at any time of the year, regardless of whether the scions were taken from the shoots of the current year or from the shoots of the previous year and whether they were grafted immediately or after the storage for several months at 5°C.
6. According to these results, inadequate thermall conditions seem to be mainly responsible for the failure of graft-union in ordinary stem-wood grafting of the maple. In trees having the congeniality of grafting, the most effective factor for the union of graft is likely to be the environmental conditions, , especially the temperature.

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1. Following varieties of Camellia were used for the present chromosome survey: each one variety of Camellia assimilis, C. granthamiana and of C. hiemalis, 14 varieties of C. japonica, 3 varieties of C. japonica subsp. rusticana, each one of C. salicifolia and of C. saluenensis and 3 of C. spp. (not identified). The karyotype analysis was also carried out with several representative forms.
2. Following different karyotypes were clearly discriminated:
C. japonica K(2n)=16V+8J+2J^t+4v
C. japonic subsp. rusticana (a wild variety) K(2n)=16V+8J+J1t+J2t+4v
C. salicifolia K(2n)=16V+8J+2J^t+4v
C. saluenensis var. Seiôbo K(2n)=17V+7J+J₁^t+J₂^t+4v
A wild form of C. japonica subsp. rusticana and a cultivated form, “Seiôbo”, of C. saluenensis were considered presumably to be either structural chromosome hybrids or true hybrid forms.
3. Result of the present chromosome survey was compiled in Table 1 and whole the data hitherto reported by many workers were represented on the list in appendix. The present authors could reveal following new facts: (i) C. assimilis was considered to be a diploid species. (ii) A hypo-triploid (3x-1) and a pentaploid forms were first discovered in C. japonica. (iii)“Otani-totsubaki”, a variety of C. reticulate, was composed of 91 somatic chromosomes including a small supernumerary chromosome. (iv) Horticultural varieties, “Tamuke-yama”and“Umegaka”, were of tetraploid chromosome constitution.
4. The polyploid series in Camellia ranged between 2x(2n=30) and 8x(2n=120) forms. More than half of species studied were the polyploid species or the species showing intraspecific differentiation of polyploidy. There could be noticed remarkable prevalence of 3x and 6x forms in clearcut contrast to the rather slight occurrence of 4x forms, and such situation would strongly suggest that the triploidy had an important role for the evolution of polyploid series in Camellia.
The discovery of 5x and 4x forms in Japonica-camellias, the latter forms being duly considered to be of hybrid origin, will give a great hope for the practical breeding on polyploid level of valuable new forms.

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In the present experiments, three items on flowering in dahlia were studied separately.
1. Effects of phtoperiod prior to decapitation on the growth rate and flowering of the lateral shoots:
When plants were grown under the day-length of 13-hours (the optimum photoperiod) after decapitation, the photoperiods given before the decapitation had no effect on the growth rate and flowering of the lateral shoots. When the plants decapitated were exposed to the photoperiods shorter than the lower critical length (12 hours), marked effect of short day-length given before decapitation on retardation of budding or flowering was observed.
Photoperiod given to the plants before the decapitation did not affect the number of florets per flower head.
2. Effects of the size of cutting upon rooting, growth rate and flowering:
Cuttings rooted well without reference to their size. The larger plants flowered earlier and more simultaneously than the smaller ones. A plant propagated from the cutting of 5g or more seems to be useable in commercial production of cut-flowers.
3. On the propagating method:
The plants propagated from crown-tubers required longer photoperiod for normal flowering than those propagated by cuttings. Some of the flower buds formed in the plants with crown-tubers remained blind under 13-hour days.

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