1. The effects of day and night temperatures on the berry growth, yield and quality of Delaware grapes were observed in each of the growth stages, berry enlargement and maturity. As a result, when expressed on the basis of berry temperature itself, the suitable day and night temperatures were approximately the same, being always about 22°C. However, for the promotion of berry maturity, a higher temperature than 22°C was favorable, although never allowed to exceed 30°C. 2. In mid-summer, the air temperature at daytime readily reached more than 30°C, and berries had a temperature higher than the air by 5° to 6°C, receiving intensive sunlight. Therefore, the optimum berry temperature for the berry growth and quality was usually found at night. Judged from this fact, a difference of temperature between day and night or a low night temperature seems to be necessary in the stages of berry enlargement and maturity in increasing yield and berry quality of Delaware grapes.
In the present investigation, metabolic products in oxidative process of fatty acid and metabolic substances in process of decomposition of sucrose were employed to clear up these effects on hastening the maturity of the fig fruits. These chemicals were applied at the best time of oleification. 1. The treated fruits with oxides of linolenic acid produced by hydrogen oxide (10% H2O2) or heating (at 60°C, for 48hrs.) treatments, were promoted the maturity more than those with only linolenic acid. While, regarding the influence between the hydrogen oxide and heating treatments, the former was more effective than the latter. 2. The application of metabolic products in oxidative process of fatty acid such as acetaldehyde, ethyl alcohol, ethylene and acetone as well as formalin markedly promoted the ripening of the fruit. Among these chemicals applied, the acetaldehyde and formalin, which are possessed of the aldehyde radical (-CHO) were most effective, followed by the ethyl alcohol and ethylene. Effect of the ketone (-CO) compound such as acetone was less than the others. 3. In the case of metabolic products in process of decomposition of sucrose, especially, the treatment with final products in carboxylation process such as acetaldehyde and ethyl alcohol were most effective, followed by pyruvic acid. Glycerine or glucose was less effective than the others. That is, the effects of these metabolic substances on hastening the maturity of the fruit are consistent with the productive order of the substances shown in process of decomposition of sucrose. 4. The mature fruits treated with some metabolic substances in oxidative process of fatty acid and in process of decomposition of sucrose were equal in size, color, and reducing sugar and malie acid contents to those allowed to mature naturally.
Measurements of the diffusion pressure deficit (D.P.D.) of Satsuma orange trees (Citrus unshiu MARC.) growing both in pots and field were carried out by the Chardakov Dye method, There was negative correlation between the D.P.D. and soil moisture content, and the inflextion point seemed to lie near the moisture equivalent. As the water saturation deficit (W.S.D.) was positively correlated with the D.P.D., it may be used to estimate the D.P.D., but it takes many more hours to measure the W.S.D. than to measure the D.P.D. by this dye settling method. The diurnal change of the D.P.D in winter took place at a higher and narrower range than in summer.
These experiments were carried out to study the effects of mineral nutrients on the acidity of tomato fruits (var. Fukuju No. 2). 1. In the solution culture, the titratable, total and combined acidities in the water extracts of whole fruits at the higher level of potassium (117ppm) were greater than those at the lower level (20ppm). Higher level of potassium induced the increases of the contents of potassium and inorganic phosphate. For the effects of phosphorus levels, the acidities and the potassium content at the higher level (31ppm) were lower than those at the lower level (5ppm). Inorganic phosphate content was increased at the higher level of phosphorus. To analyze such converse effects of both nutrients, partial correlation coefficients were calculated between the titratable acidity and the content of potassium or that of inorganic phosphate. It was shown that the titratable acidity was significantly correlated with the potassium content (r=0.96), but not with the inorganic phosphate content(r=-0.03). The same was true for the total acidity. Therefore the phosphorus effect seemed to be an indirect one on the acidities of fruits. The combined acidity and the potassium content at the higher level of nitrogen (140ppm) were lower than those at the lower level (40ppm). On the titratabie and total acidities, however, nitrogen levels had the different effects depending on the level of potassium supplied. At the lower level of potassium, the higher level of nitrogen decreased these acidities, whereas it increased them at the higher level of potassium. Gelatinous pulp weight expressed as a percentage of whole fruit was significantly decreased at the higher level of either nitrogen or phosphorus, but not affected by potassium levels. Examination of interaction between nutrient effect and fruit tissue indicated that effects of nitrogen or phoshorus on the acidities and the potassium content were not different with regard to the kind of tissues, while effect of potassium on the titratable and total acidities and the potassium content were greater in gelatinous pulp than in wall tissues. 2. To study the effect of forms of nitrogen, the ratio of NO3-N to NH4-N was varied (10:0, 5:5 and 3:7), while the concentration of total nitrogen was held constant at 70ppm. Titratable and total acidities of fruits supplied with ammonium nitrogen (NO3: NH4=5:5 or 3:7) were lower than those of fruits supplied with nitrate nitrogen only (10: 0). Combined acidity and the potassium content were, however, decreased at the 5:5 solution only. The titratable acidity expressed as a percentage of total acidity was lower in the fruits supplied with ammonium nitrogen than those supplied with nitrate nitrogen only. 3. The effects of various rates of phosphorus or potassium fertilizers were examined on fruits from plants grown in pots containing the volcanic ash soil. Potassium fertilizers had almost the same effect on the acidities and the potassium content with those found at the experiment in solution culture. Phosphorus showed no significant effects on the acidities. These results obtained above suggested that effect of potassium on the acidities was distinctly greater than those of nitrogen or phosphorus, and that the acidities of fruits were intimately related to the content of potassium. The apparent effect of potassium were thought to be based on the following two facts, namely (a) the almost proportional relations among the titratable, total and combined acidities were maintained in tomato fruits at the incipient colour stage, and (b) the combined acidity, i.e., the content of total cations, was linearly related to the potassium content.
Lettuce (Lactica sativa L. var. capitata, cultivar Great Lakes) was grown in gravel culture using HOAGLAND′S No 2 solution under polyvinyl plastic growth chambers to investigate the practice of CO2 enrichment of the atmosphere on the growth. Four chambers were employed with each at 300 (air), 900, 1, 500 and 3, 000ppm CO2 for 8 hours daily from April 1 to May 20, 1965. 1. Difference in growth and appearance of the plants grown under the normal and the above normal levels of CO2 were apparent within 20 days. Fresh and dry-weight yields, number of leaves and leaf area increased with increasing CO2 concentrations, while percentage of bolting decreased. An enhancement of NAR by increasing CO2 concentrations was observed. 2. The effect of increased CO2 concentrations was on growth and yield were compared with outer and inner leaves of lettuce at the end of the experiment. In the inner leaves, fresh-and dry-weight yields and number of leaves increased with higher levels of CO2, and also in the outer leaves similar effects were found in all except number of leaves. 3. The contents of chlorophyll, nitrogen, phosphorus and potassium in leaves were determined for outer and inner leaves at the end of the experiment. All the measured constituents varied with the part of plant analyzed or CO2 concentrations treated. Chlorophyll contents in both outer and inner leaves tended to decrease with higher levels of CO2 regardless of plant part. In the outer leaves, N, P and K contents increased with increasing CO2 concentrations, while in the inner leaves a decrease occurred in P and K contents but N increased as CO2 conentrations were raised.
1. An experiment was conducted to clarify the photoperiodic sensibility to flower bud differentiation, belting and heading in lettuce varieties. 2. Flower bud differentiation and bolting were hastened under long day condition. Short day treatment inhibited the reproductive development and influenced progressively on the heading 3. The short day treatment for 3 to 6 weeks from germinating effected intensively on the developmental phases after the treatment. This phenomenon was confirmed as an after-effect of short day reatment. 4. The apparent difference of photoperiodic sensibility bteween varieties was observed. The sensibility of variety“Wayahead, Edogawa strain”was higher than that of“Premier Great Lakes”and“Great Lakes 366”. 5. Owing to the results of the experiment, a new cultivation type for the commercial production during the middle of summer has been established.
Wooden frame experiments were conducted to study the effects of the application ratio of potassium to nitrogen on top growth, tuber-formation and-thickening of sweet potatoes. Four types of soil differing in their clay content were used. Two cuttings were planted in each frame. 1. According to the increase of the application ratio of potassium to nitrogen, top growth was gradually weaken throughout the growing period in every type of soil, and also the percentage of parts of young vines decreased. 2. Small application ratio of potassium to nitrogen was unfavourable to tuber-formation due to the vigorous vine growth during the period of tuber-formation, however, it was favourable to the increase of tuber yield, especially that of large tubers, as the vine growth was vigorous after tubers began to thicken. 3. As the application ratio of potassium to nitrogen increased, the percentage of dry matter content of tubers in every type of soil gradually decreased.
It was examined by a serological method whether the change in the protein-pattern of scaly leaf of tulip bulb can be utilized as a signal in receiving the proper intensity of low temperature treatment in the bulb stage, or not. By using precipitation obtained from the antigen-antibody reaction effected by the double diffusion method according to Ouchterlony, six precipitin bands were detected in Mozart, and eight precipitin bands in Zwaneburg. It was found that the low temperature treatment reduces the protein level of bulb scales in both varieties. This reduction was due to the disapperance and decrease in the quantity of some special proteins. It was confirmed also in the result of analysis by immunoelectrophoresis that the disapperance of special proteins occurs with the low temperature treatment of bulbs. It was suggested from the above result that pursing the change in the protein of scaly leaf due to the low temperature treatment of bulbs by the serological method, it is possible to obtain signals for determining the proper intensity of low temperature treatment and further to establish the standard for selecting suitable varieties in the forcing culture.
1. This experiment was practiced to identify anthocyanin pigments in flowers of 19 lily varieties by paper chromatographic and spectrophotometric methods. 2. The anthocyanins were identified in 15 varieties out of 19, and they were keracyanin (Cyanidin-3-rhamnoglucoside) and minor anthocyanin. 3. Four varieties were devoid of anthocyanin pigments and in 2 varieties with white flowers no leuco-anthocyanins were detected.
This study was conducted to obtain some relations between the formation of adventitious roots and auxin activity in cuttings. 1. IAA content in the cuttings gradually increased from cutting to rooting and its content showed the highest value at the time of formation of root primordia and the development of roots and then decreased. The increase of IAA content in cuttings tended to increase rapidly in cuttings of Rose-Moss (Portulaca grandiflora Hook.), but slowly increased in cuttings of Korean Weigela (Weigela coraeensisThunb.). 2. The amount of the synthetic auxin which was absorbed by stem of cuttings was the highest content after treatment and gradually decreased, but few quantities of them was recognized even at the time of rooting. The synthetic auxin treatment of the cutting tended to increase the natural IAA in cuttings of Korean Weigela. 3. The changes of IAA content of etiolated shoot of Lily Magnolia (Magnolia liliflora Desrouss.) tended to increase IAA before rooting and decreased at the time of rooting. 4. Increase of IAA content in stem on Rose-Moss cuttings tended to similar on the other plant, but its content of the stem removed the leaves tended to delay. 5. Although the close relation between activity of auxin and the rooting response of cuttings was not found from this experiment, the increase of IAA content in cuttings is one of the most important factors on rooting of cuttings, but the formation of adventitious roots did not take place even under the high level of IAA content. It may be said that essential unknown compounds which will be transported from leaves to stem might be correlated with IAA to rooting of cuttings.
It has been well known that gas composition and temperature of atmosphere can affect the respirations and the qualities of some kinds of fruits such as apples, pears and bananas, but the effects of these factors on the storage of vegetables has not been shown so clearly. This study was undertaken to determine the effect of these factors on the quality and the metabolism of spinach (Spinacia oleracea) during CA-storage. 1) Spinach stored in CA-condition (O2; 8.6-12.5 %, CO2; 8.9-42%) kept their good quality for three weeks at 5±0.5°C. Spinach stored in 11% O2 and 40% CO2 at 5°C was not affected by carbon dioxide injury, but kept good green color and turgidity during storage. 2) The chlorophyll content in spinach didn′t decrease during CA-storage at 5°C, but the content decreased gradually at room temperature (February-March). Especially the chlorophyll content in spinach leaves in air decreased markedly. The CA-condition improved the color of stored product by retarding chlorophyll breakdown. 3) The l-ascorbic acid content in leaves and stems decreased rapidly during common storage. These decreases were kept down by CA-condition, so spinach. leaves stored in 40% CO2 and 11% O2 kept high content of ascorbic acid at the end of storage period. 4) O2 uptake in Warburg respirometer of cell free preparations from leaves increased gradually during storage of spinach, they increased just at the time when l-ascorbic acid content in leaves decreased. 5) In cell free extract succinic acid-1, 4-14C was converted into the other acids in TCA-cycle. The largest percentage of conversion was fonud in cell free extract from spinach leaves stored in common storage for 17 days, the smallest one was found in cell free extract from spinach stored in 40% CO2 for 17 days. Succinic dehydrogenase activities in spinach leaves decreased markedly for the initial 10 days of storage, then increased slowly in their activities. Succinic dehydrogenase activities of spinach leaves stored in CA-conditions were weaker than those of spinach stored in common storage at the end of the storage period. These results comfirm a hypothesis that the controlled atomosphere condition can inhibit the succinic dehydrogenase activities and the respiratory metabolism in fruits and vegetables during storage, accordingly prolong theirr storage lives.
Tomatoes (Licopersicon esculentum MILL. ) of three stages of maturity, mature green, breaker and light pink fruits were used in this experiment. Tomato fruits were irradiated with 60Co gamma rays at 0r, 5. 0×104r and 1. 0×106r at the rate of 2. 5×105r/hour. Temperatures during the irradiation and the storage were at about 20°C. The results obtained here were as follows: 1. The pigmentation of tomatoes which were irradiated by gammarays at stages of breaker and light pink was delayed. The destruction of chlorophyll and the increasing of lycopene during ripening were apparently suppressed with higher doses. Gamma irradiation caused the considerable softening of the tissue immediately after irradiation. The subsequent change of softening in irradiated fruits was smaller than that in unirradiated ones. There was a decrease in protopectin in irradiated fruits immediately after irradiation. The titrative acidity and the amount of total sugar were not affected by gamma irradiation. The reduction of ascorbic acid by irradiation seemed to be greater in fruits of breaker stage than in those of light-pink. 2. Carbon dioxide production of tomatoes irradiated at breaker stage increased with higher doses and this increased carbon dioxide production lowered to some extent at 24 hours after irradiation. These irradiated fruits exhibited the climacteric-like rise at the same period as that in unirradiated ones. Carbon dioxide production in tomatoes irradiated at light-pink stage was slightly greater than that in unirradiated ones, and light-pink fruits did not exhibited the climacteric like rise in both irradiated and unirradiated fruits. 3. The effect of pyruvate and malate on carbon dioxide output in tissue slices increased in irradiated fruits more than in unirradiated ones. Gamma irradiation at 1.0×106r stimulated the ethylene formation. The increasing rate was higher in mature green fruits than in others. The rates of ethylene production decreased in all irradiated fruits 5 days after irradiation. 4. The organoleptic evaluation showed the acceptability of the irradiated tomatoes lowered with the high dose.
1. As one of the evaluating methods in fresh tomatoes, firmness of fruit and color of mushed tomato were determined at the various maturing stages. When these two values were determined just after the harvest of tomato fruit, they have been closely correlated to the ripeness score which was set up in the previous work. 2. The ripeness score was also closely related to these two values described above, when tomato fruit ripened after the harvest as well as on tomato plants. Therefore the ripeness score should be considered as an important factor which indicates the quality of fresh tomatoes. 3. There was difference between the taste of two sorts of tomatoes, even they had the same ripeness score; for example, one was ripened on plants and the other after the harvest. It is natural that the former was more delicious than the latter, needless to say. So both the ripeness score and the organoleptic evaluation of taste should be considered. 4. It was found that the acid value might indicate the quality of fresh tomatoes, because this value decreased very fast during the storage at high temperature, though the amounts of other components scarecely varied.