During the years 1961-1962, the rate of the potential evapotranspiration in Satsuma orange trees (Citrus unshiu MARCOVITCH) has been determined by lysimeter method at Anjo, and the values obtained were compared with the values computed by THORNTHWAITE'S formula. On the other hand, the actual evapotranspiration (consumptive use of water) in an orchard of Satsuma orange has been evaluated by “water balance sheet method” in the south region of Chita Peninsula. 1. Potential evapotranspiration; The values measured by lysimeter and the values computed by THORNTHWAITE'S method are shown in Table 1. Annual total of the former values was about 100mm higher than that of the latter. 2. In order to evaluate the potential evapotranspiration of mature citrus orchards, “Crown volume ratio” (tree crown volume per planted ground area ratio)was determined. This index of young trees in lysimeter experiment was 20% lower than the value measured in the mature citrus groves (30 year's old). Assuming that the evapotranspiration becomes greater in proportion to the increase in “Crown volume ratio” under the field condition, the annual total value of potential evapotranspiration becomes about 1200mm. It seems that this is the critical value of evapotranspiration from the mature citrus groves which have dense foliage, and deep root system. 3. Actual evapotranspiration; It was calculated as follows; U=P.W.L.+R outgo of profile water loss effective precipitation water (deficit of water) (income of water) where U is consumptive use (actual evapotranspiration), P. W. L. is total moisture loss from soil profile, and this was estimated by soil weighing method. The values calculated by this equation were compared with open pan evaporation and the values calculated by BLANEY-CRIDDLE'S formula. The coefficients of BLANEY-CRIDDLE'S formula and the proportional coefficients of open pan evaporation were estimated as follows; a) Jun. -Oct. U=0.5F or U=0.8E b) Nov. -May U=0.4F or U=0.6E where F is BLANEY-CRIDDLE'S function and E is open pan evaporation. The seasonal change of the computed values for actual evapotranspiration is shown in Table 2. 4. Conclusion; It may be concluded from these investigations that the potential evapotranspiration of the vegetation which have dense foliage of the mature Satsuma orange groves and holds moisture in field capacity is 7mm/day during the season of great demand for moisture, but actual evapotranspiration is expected to be between 5-6mm/day under the wet condition of soil profile and 3-4mm/day under its relatively dry condition at the time of maximum moisture use.
1. The alternate bearing habit of an Unshu orange orchard (33 years old in 1929) was investigated on the basis of yield records since 1929. In this orchard, where fruit thining and pruning had not been practised, yield per 10 a. was about 6, 000kg in on years and 1, 000 to 2, 000kg in off years. This fluctuation in yield had increased year after year. 2. Annual variations in the yield, percentage of terminal shoots, ratio of blossom-bud to node number, and percentage of secondary shoots sprouting from the fruiting and non-fruiting branches testified the alternate bearing tendency statistically. 3. Annual variation of fruit number per unit volume (m3) of tree crown was also indicative of alternate bearing habit. 4. The most desirable ratio of fruiting shoots to spring flush which gave sufficient yield every year was confirmed as 40 to 45 per cent. However, the alternate bearing trees put forth large number of fruiting shoots and small number of spring flush in an on year, while in an off year these trees had large number of spring flush with a correspondingly small number of fruiting shoots. This pattern of growth in trees induces the tendency of alternate bearing. 5. Percentage of flower bud in on and off years varied in the range between 47.1 and 16.9 per cent. In some cases the fruiting shoot in off year produced flower buds in the next year. 6. Alternate bearing habit is the expression of ill balanced number of fruiting shoots to the total number of shoots produced. Excessive bearing of flowers and development of fruits make the tree difficult to form the flower buds owing to the lack of florigen accumulation. In excessive fruit bearing tree, even spring flush could not produce the flower in the next year. This shows the remarkable alternate bearing habit due to ill balanced ratio between the fruiting shoot and spring flush of the past year.
The influence of suppling nutrient solution lacking N, P, K or Ca during certain periods on vine growth, yield and quality of berries of Black Queen variety were studied by means of sand or solution culture. 1. No application of nitrogen from December to the middle of April did not show unfavorable effect on vine growth and yield, but lack of nitrogen during any period from the middle of April and later on decreased the yield. It was true even during the period as late as September. No application of nitrogen after August (when berries began to color) forced coloration of berries, but had no effect on their quality. 2. Phosphorus was necessary for vine growth and yield from the middle of March (when sap began to flow) on, and its delayed application after that time decreased the yield. No application of phosphorus from September to the middle of March or after late July (when seed was hardening) showed no unfavorable effect. 3. No application of potassium from December to the middle of April and of calcium from December to the middle of May showed no unfavorable effects on vine growth and quality of berries, but lack of potassium and calcium during any other period excepting the above mentioned decreased the yield.
Changes of quality in the pectic substances of Bartlett pears produced in the different growing areas during maturation and after-ripening, of canned products of ripened Bartlett pears, and of Japanese pears of optimum ripeness were investigated. Preparation and extraction of pectic substances from pears: The fruits were peeled, halved, cored and grinded. They were extracted with boiling 70% ethylalcohol to remove sugars. Extraction of pectin from sugar-free dried samples was performed successively with three agents in the order; cold water, cold 0.4% sodium hexametaphosphate, and 0.05N hydrochloric acid at 85°C. Water soluble pectinate and pectate (WSP) were extracted with cold water, water insoluble pectinate and pectate (PSP) with hexametaphosphate solution, and protopectin (HSP) with hydrochloric acid solution. Total pectin is the sum of these three fractions. Pectin content (Capectate), inherent viscosity and pectin unit were determined for each extracted pectin solution.
Recently large acerage of orchards has been established on virgin soils derived from granite in“Setouchi”district. In this experiment, the effects of application of N, P, K and Ca fertilizers on the growth of young fruit trees were observed with peach, Japanese persimmon, citrus, grape, loquat and chestnut, planted in the pots filled with granite soil. The granite soil used contained 10% of clay, 0.079% of humus, 0.013% of total nitrogen, 0.0038% of available phosphoric acid, 0.056% of available potassium, 0.316mg/100g of exchangeable calcium and 3.33mg/100g of exchangeable magnesium. Its absorption coefficients of nitrogen and phosphoric acid were 98 and 212, respectively. In the plot where phosphorus was not given, tree growth was most inferior in every fruit tree except for chestnut. When nitrogen was not supplied, the growth was also very poor in all species. Chestnut tree made better growth in the P-lacking plot than in the N-lacking plot. No effects were observed of the application of potassium. Calcium application improved the growth of citrus exclusively. All of the fruit trees made best growth when the above mentioned four elements were supplemented with farm manure.
The flowering and fruiting habits of broad beans were studied, using 6 varieties, i.e. Wase, Kyûryû, Sanuki, Bôshû, Issun and Nagasaya. 1. Seasonal change of number of open flowers was similar to that of number of pods harvested in its pattern. But, the set percentages were higher in early part of the flowering period. 2. The varietal differences in the number of flowers per plant and the set percentage were hardly recognized among the 6 varieties tested. The percentages of harvested pods to the number of flowers were about 20%, but they varied with sowing dates and other factors. 3. The first flowers of lower inflorescences opened earlier than those of upper ones in the same branch. 4. The first flower of the main stem generally opened first, and the first flowers of branches opened generally in due order with the order of emergence of those branches, although there were some exceptions. In most cases, the flowers of lateral branches of the second order opened much later than those of the first order lateral branches. 5. The flowers open indeterminately in each inflorescence. 6. The number of flowers per inflorescence varied with nodes of branches, being few in both upper and lower nodes and increasing toward the middle portion. Most branches had 2-flowered inflorescences in the lowest nodes which bore inflorescences. Some nodes in the tip of branch bore 1-flowered inflorescences. 7. Set percentages of 1-flowered inflorescences were less than those of the first flowers of 3-flowered inflorescences or of 4-flowered ones. It probably depends on the fast that 1-flowered inflorescences appear in the tips of branches where the nutrition become poorer. 8. In the case where more than 2 flowers set in one inflorescence, those flowers opened generally on the same day. But the frequency of the cases in which both 2 flowers of the same inflorescence set were rather low, and it hardly took place that 3 flowers of the same inflorescence set. 9. Mostly only the pods which came from the first flowers of the inflorescences could be harvested. In some cases the second flowers set pods that could be harvested. But the upper flowers than the third in the inflorescence rarely set. 10. Of the 2-flowered inflorescences, it was more common that the lower flower opened earlier than the upper flower by one day. The cases that both upper and lower flowers opened on the same day and that the lower one opened earlier by two days took place less often. The cases that the differences of opening of two flowers of the same inflorescence were more than three days were very few. In the inflorescences that bore more than three flowers, the differences of anthesis dates of the first and the second flowers were similar to the abovementioned cases of 2-flowered inflorescences.
1. Effect of photoperiod on the vegetative and reproductive responses. Tomato seedlings were grown under 4-, 8-, 12-, 16-, 20- and 24-hour photoperiod, respectively, for 60 days from cotyledon expansion. The longer the photoperiod up to 16-hour-day, the more vigorous the plant growth, the earlier the date of flower bud differentiation, and the more the number of flowers. The photoperiod longer than 16-hour-day, on the other hand, restricted the plant growth and retarded the flower bud differentiation, resulting in the increase in the number of leaves to the first inflorescence and the less number of flowers. It may be concluded that the most favorable photoperiod for the plant growth and flower formation is 16-hour day. 2. Effect of combination of photoperiod with temperature on the vegetative and reproductive responses. The seedlings were grown in all the combinations of two photoperiods (8- and 16-hour) with four different thermoperiods (day and night combinations of 17°C with 24°C). The long-day induced the more vigorous growth followed with the earlier flower bud differentitation, development and the increased number of flowers than the short-day at any thermoperiods. Day-temperature of 17°C retarded the plant growth, the flower bud differentiation and its development, and on the other hand, increased the number of flowers than 24°C at both night-temperatures. Night-temperature of 17°C hastened and invigorated the flower bud differentiation, resulting in the decrease of the number of leaves to the first inflorescence with the increased number of flowers than 24°C at both day-temperatures. 3. Effect of combination of light intensity and night temperature on the vegetative and reproductive responses. Seedlings were grown in all the combinations of four different light intensities (100, 74, 49 and 24 per cent of natural day light) with two night temperature (17°C and 25°C). The higher the light intensity, the more vigorous the growth, being followed with the earlier flower bud differentiation with the decrease in the number of leaves to the first inflorescence, the increased number of flowers and the acceleration of their development in either of the night-temperatures. 4. Relationships between the flower formation and chemical constituents in tomato seedlings. The chemical constituents in the top of seedlings at 50 or 60 days-stage grown under all combinations of photoperiods, light intensity and thermoperiod varied significantly correlating with the total number of flowers up to the third inflorescence. The seedlings grown under the longer photoperiod, higher light intensity and lower night-temperature showed higher level of carbohydrates, especially total sugars, and nitrogen compounds, especially protein, and differentiates many flowers. 5. Seedlings of heavy top weight in comparison with the plant height, with high level of sugars and protein, yield much more fruits, grown under the above related any combinations of light and temperature factors.
An experiment was carried out to ascertain relationship between respiration and coloring of fruit using the variety Mitsuoka in 1960 and 1961 at Faculty of Agriculture, Shinshu University. Fruits were harvested on the 30th, 38th, 47th, 52th and 58th day after flowering in 1960, and 25th, 33th, 37th, 41th and 43th day after flowering in 1961. Also, the fruits harvested on the 39th day after flowering in 1961 were stored at room temperature (22-25°C), 30°C and 35°C, respectively. Furthermore, the fruits harvested on the 40th day after flowering were stored with oxygen (21%) and carbon dioxide (1%) for 10 days. 1. The respiratio rate of fruits decreased from immature stage to green mature stage and increased from green mature stage to mature stage. The climacteric peak of respiration rate was formed when the whole parts of fruit was colored, and the respiration rate was decreased thereafter. The increase and decrease of respiration rate in the fruit were closely connected with chlorophyll and carotenoid pigments of fruits. 2. On the relation of storage temperature to respiration rate of fruits, fruits stored at room temperature (22-25°C) were higher in climacteric peak than those stored at 30°C or 35°C, but when harvested at immature stage, fruits stored at 30°C and 35°C had higher respiration rates than those stored at room temperature. On the pigment contents of mature fruits, fruits stored at room temperature has a large lycopene content, and those stored at 35°C were scarce in lycopene and appeared yellow. Fruits stored at 30°C were mediate between room temperature and 35°C. 3. On the fruits stored with oxygen or carbon-dioxide, respiration rates was inhibited more strongly in the latter fruits than in the former. Accordingly, the pigment contents of fruits stored in carbon-dioxide were less than those of oxygen storage fruits. Especially, at the end of storage, there was a remarkable difference between the two treatments.
Effect of nitrogen supply and omission at the various stages of growth on the absorption of nutrients and on growth and yields of tulip were studied with 11.0g bulbs of‘William Pitt’in sand culture. Growth period was divided into the following five stages: I. Stage of root system development (Nov. 1-Mar. 14), II. Stage of earlier vegetative growth (Mar. 15-Apr. 19), III. Stage of later vegetative growth (Apr. 20-May 4), IV. Stage of bulb weight increase (May 5-May 31), and V. Stage of maturity (June 1-June 24). 1. Growth of tops was remarkably reduced by the omission of nitrogen: leaves and flowers were considerably smaller and flowering was a little hastened than those of complete nutrition. Among the stages, stage II showed the greatest effects. 2. Withering up of tops was accelerated by the omission of nitrogen at stage IV and delayed by the supply of nitrogen at this stage. The other stages had little effect on it. 3. The effect of nitrogen on yields was the greatest at stage II and III, and much less at the earlier or later stages. Reduction of bulb weight due to nitrogen shortage was greater in lateral bulbs than in main bulbs. 4. The omission of nitrogen at later stages indicated more marked reducing effects on the nitrogen content in bulbs than at earlier stages. And nitrogen supply at stage IV kept the content at its highest level, irrespective of the nitrogen supply before and after that stage. 5. The nitrogen content of tops showed the same trend as that of bulbs; the only difference between them was that plants suffered from nitrogen dificiency for the period of vegetative growth failed to recover their nitrogen content in the tops by the nitrogen supply at stage IV. 6. There were observed positive correlations between the contents of nitrogen and phosphorus in tops, bulbs and flowers. But when plants were grown under the condition of extreme deficiency of nitrogen, phosphorus concentration in each part of plants did not reduce so much as that of nitrogen. 7. Potassium content in each part of plants showed no distinct differences among the treatments. 8. The differentiation of flower bud in the harvested bulbs during the storage period was extremely delayed by the severe deficiency of nitrogen. The delay in other cases, however, could not be attributed either to bulb weight or final content of nitrogen, but to the nitrogen omission of stage I and/or II. 9. There happened to be noted an unknown disease which caused brown necrotic spots on the surface of the outermost living scales. This disease prevailed when plants suffered from nitrogen deficiency during the period of their vegetative growth and received sufficient nitrogen supply at the stage of bulb weight increase. This fact suggested that the trouble might be of physiological nature. 10. Among the studied five stages, the absorption of nitrogen was more active at stage II, III and IV. On the other hand, the efficiency of producing bulbs by the absorbed nitrogen was higher at stage I, II and III. It is considered, therefore, that stage II and III should be the most important period for nitrogen supply.