Experiments were carried out to clarify the effects of difference in nitrogen content in leaves due to variation in nitrogen fertilizer application from May to August on the growth and quality of fruits of young satsuma mandarin trees. An additional objective was to clarify the optimum nitrogen content in the leaves during summer and autumn seasons from the point of view of improvement in fruit quality. 1. Foliar analyses revealed that leaf N changed 10 to 15 days after N application. These changes in leaf N were proportional to the amount added and the levels then persisted until the fruits were harvested in December. On September 3, the % leaf N were: N0: 2.08; N1: 2.78; N2: 3.21; N3: 3.40 and N4: 3.73. Leaf N was inversely related to K level as were Ca and Mg contents. Fruit N content followed a trend similar to that of leaf N. 2. Differences in leaf coloration became apparent among treatments after the first of June and clear in August, when the leaves of N0 plot were light green while those of N3 and N4 were dark green. Older basal leaves of N0 plot became yellow and began abscising in August, when the fruit skin color was light green. These trees lacked vigor notably. The coefficient of correlation, r, between leaf color index and leaf N was 0.823**; that between chlorophyll content and leaf N was 0.695**. 3. The fruit yield in decreasing order by plots was: N3, N4, N2, N1 and N0. The trend of average fruit weight from the plots paralleled that of yield. Fruit shape was unaffected by N treatments. Fruit color index revealed that fruits from N1 and N2 were superior to those from N0 plot. While fruits from the No plot lost chlorophyll earlier than those from the N plots, they did not develop bright orange color and the color grade at the harvest time was less than that of others. Soluble solids of the juice was highest in fruits from N0 and N1 plots, decreasing with increasing N applied. Citric acid content of the juice was variable although the level in N0 and N1 plots was higher than others. N0 difference in sugar/acid ratio was detected among fruits from the differentially treated trees. It is concluded from these observations that the best quality of satsuma mandarin was attained when the leaf N in summer to early autumn ranged from 2.6 to 2.8% as was found in the N1 plot.
This paper reports on the effect of leaf water potential on growth of satsuma mandarin (Citrus unshiu MARC.) trees. 1. In late August, fruit diameters began to shrink from about thirty minutes after sunrise, continued to contract during the day and began to increase near the time of sunset. The amplitude of diurnal contraction and expansion which became more pronounced with reduction in leaf water potential (φmax), before sunrise became conversely smaller when φmax dropped below -12 bars, because of no full recovery occurring at night. 2. Growth of fruits and trunks was more sensitive to leaf water stress than that of leaves. Fruits and leaves stopped to grow when φmax dropped to about-8 bars and -15 to -20 bars, respectively. 3. Leaf water potential(φmin)and leaf diffusion resistance (RL) measured between 1:00 and 2:00p.m. were also related to fruit growth. Fruit growth stopped completely when φmin and RL reached -17 bars and 16sec/cm, respectively. In a shaded tree, however, fruit growth stopped at -9 bars of φmax (2 bars lower than an unshaded tree) and 16sec/cm of RL, but φmin seemed to have no effect on daily fruit growth. As a result of this experiment, among φmax, φmin and RL, fruit growth was closely related to RL and φmax, but it is necessary to exercise caution in interpreting RL because RL was highly sensitive to changes in solar radiation. In the field work, then, it may be quite all right to consider that φmax can be used in estimation of plant growth.
In order to clarify the relationship between a physiological disorder, so called “Yuzuhada” which means uneven rind of fruits of Japanese pear, and inorganic nutrients, the changes of mineral contents in leaves and fruits of the disordered and healthy Nijisseiki pear trees during the period of fruit growth were investigated from 1973 to 1974. The results were as follows: 1. Comparing with disordered and healthy trees in the same orchard, the contents of N and Ca in leaves of the disordered trees were lower than those of the healthy trees, but each contents of K and Mg had a tendency to be higher in the former than in the latter. K content in leaves of the disordered trees was remarkably high at the period from the end of July to the early of August. B content in leaves was lower in the disordered trees in the early stage of fruit growth. The contents of K, P and Mg in fruits showed a tendency to be somewhat higher in the disordered trees than those in the healthy trees, while N, Ca and B contents in fruits did not show consistent difference between them. 2. The seven pear orchards which were different in field location and tree age were selected and investigated late in July to know the balance of mineral contents in leves of the disordered and healthy trees. The results showed that the rate of K content to N, Ca and Mg content was higher in the disordered trees; Ca/K 2.14 (healthy) & 1.14 (disordered), Mg/K 0.59 (healthy) & 0.32 (disordered), and (Ca+Mg)/K 2.68 (healthy) & 1.56 (disordered).
1. The relationship between gall swelling and plant growth regulators after inoculation of an egg mass of root-knot nematode (Meloidogyne incognita var. acrita) on the second internode of the balsam plant (Impatiens balsamina) were studied. Changes in levels of auxin, cytokinin, gibberellin and ethylene, and the effect of application of exogenous plant growth regulators (GA3, GA4+7, IAA, KN, MH, CCC, B-9) on gall swelling were investigated. 2. Auxin and cytokinin activity sharply increased one week after inoculation, and no further increase was found thereafter. Ethylene evolution from the gall tissues significantly increased during gall swelling. Endogenous levels of auxin, cytokinin and ethylene in the gall tissues were considerably higher than those in the normal tissues at every stage. 3. GA3, IAA and especially IAA+KN promoted gall swelling, while plant growth retardants such as CCC, B-9 and MH remarkably inhibited gall swelling when applied one week after inoculation. When plant growth retardants applied 3 weeks after inoculation, KN and IAA+KN promoted gall swelling, and IAA+KN was as effective as its application at one week after inoculation, while CCC and B-9 inhibited gall swelling. Ethrel concentration was proportional to gall swelling in the range between 100 and 500ppm.
In order to clarify the mechanism of necrosis development in the resistant host in response to chestnut gall wasps, polyphenoloxidase and some dehydrogenase activities in gall and healthy tissues of susceptible and resistant varieties were investigated histochemically. In healthy tissues, polyphenoloxidase (PPO) activity was high in parenchymatous tissues surrounding vascular bundles but low in mesophyll tissues. In general, the activity in gall tissues was reduced as compared with healthy tissues of both susceptible and resistant varieties. But, PPO activity in gall tissues of resistant varieties was higher than that of the susceptible varieties. Also, boundary tissues intervened between healthy and gall tissues of the former varieties, and such boundary tissues consisting of parenchymatous cells around vascular bundles displayed a large increase in activity. Reduction of tetrazolium salts in gall tissues of susceptible varieties was decreased by treatment with heating, freezing and enzyme poisons. This implies that the reduction is caused by coenzyme requiring enzymes. Dehydrogenase activity was also inhibited by 10-3M tannic acid or 0.4% tannins obtained from the resistant chestnut bark. Dehydrogenase activity was low in normal young leaf tissues but very high, similar to apical tissue, in the infected tissues (gall tissues) of the susceptible varieties. by the parasite. However, dehydrogenase was not activated in those of the resistant varieties. Healthy tissues were low in NADP-hydrogenase and glucose-6-phosphate dehydrogenase activity. However, as the normal tissues galled, the tissues of susceptible varieties showed high activities of NAD- and NADP-hydrogenase, glucose-6-phosphate dehydrogenase and iso-citrate dehydrogenase which might play important roles in the physiology of gall formation and nutrition supply for the parasite. On other hand, the tissues of resistant varieties were low in activity in coenzyme requiring enzymes.
In many crops, calcium deficiencies in various organs and tissues are often exaggerated due to the low rate of mobility of calcium in plant tissues, and especially under unsuitable conditions for plant growth. Studies were carried out to clarify the influence of naphthaleneacetic acid (NAA) on the mobility of calcium in tomato plants. In the first experiment, tomato seedlings having reached the anthesis stage of the first flower cluster were grown in a nutrient solution with and without calcium, and treated with foliar spray of NAA (10-5M) or CaCl2 (4×10-2M), respectively. The growth of treated plants and the distribution of calcium compounds in leaves of these plants were investigated. In the second experiment: (1) the difference of 45Ca absorption between the plants treated with and without foliar spray of NAA (10-5M) was investigated; (2) immediately after the plants were grown in complete nutrient solution with 45Ca for 4 days, these plants were transferred to a non-45Ca and low calcium nutrient solution with and without foliar sprayed treatment of NAA(-5M), and also held for an additional 21 days. Thereafter, these plants were tested for radioactive analysis and for radioautograms; and (3) 45Ca was applied onto the surface of the leaf and stem, and its subsequent detection on other parts of the plants was made by radioactive analysis. The results are as follows: 1. In the plants grown in nutrient solution without calcium, the phenomena of calcium deficiency was found in all clusters and new unfolded leaves of control plants. The same phenomena were found in the third cluster and new unfolded leaves of CaCl2 treated plants. Oppositely, no phenomenon of calcium deficiency was found in NAA treated plants. 2. In case of plants which were grown in nutrient solution without calcium and treated with NAA, water soluble fraction calcium in plant tissues apparently increased in the first leaf under the first cluster, and also much more NaCl soluble fraction calcium increased in the first leaf under the second cluster than those in control plants. In the plants treated with CaCl2 only, the higher percentage of all calcium compound was found in leaves than the control plants. 3. By the foliar spray treatment with NAA, the treated plants, which were grown in nutrient solution with low calcium level marked with 45Ca, showed a greater amount of radioactivity than plants without NAA treatment. 4. Once 45Ca has been deposited in plant tissues, even if a particular migration period be provided, a significant quantity of calcium is not usually transported into new formed tissues. Applying NAA by foliar spray, a very pronounced calcium movement in plant tissues occurred during the 21 day migration period. 5. Applying 45Ca with NAA onto the leaf or stem surface, these plants showed a higher amount of 45Ca movement than plants without NAA treatment. But when 45Ca and NAA were treated in different parts of the plant, no effects of NAA on the 45Ca movement were found.
Variations in the concentration of CO2 in the atomosphere of melon plants which were grown under tunnel shaped coverings of plastic sheet (abbreviated as tunnel) were investigated. The tunnels were laid in an ordinary plastic greenhouse (18m× 50m=900m2 in size) set up on the sand dune field. 1. The CO2 concentration at nighttime showed the highest value in the non-hole poly tunnel with bare ground condition. At 17:00, when the tunnels were closed, the CO2 concentration increased by a ratio of 65ppm/hour and reached 1700ppm at 7:00 the next morning. Then with the increase of solar radiation intensity, the CO2 concentration decreased, in turn, by a ratio of 230ppm/hour. 2. Under the non-hole-poly tunnel with mulched ground condition, the pattern was the same as for the non-hole-poly tunnel with bare ground condition, but the CO2 concentration was about 200ppm lower than the concentration for the bare ground condition. The decreasing rate of CO2 concentration after sunrise was larger and constant, than the concentration for the bare ground condition, showing 280ppm/hour. 3. During the daytime when solar radiation was high the non-hole-poly tunnel with mulched ground conditions showed a lower CO2 concentration (after 11:00 ca. 50ppm) than that of the surrounding air of the plastic greenhouse. On the other hand, in the tunnel with bare ground conditions, it showed a higher value of ca. 300ppm. In the rainy afternoon it showed a higher value of ca. 900ppm. 4. At nighttime the CO2 concentration in the hole-poly tunnel usually remained very low, as compared to that in the non-hole-poly tunnel. At one hour after closing the hole-poly tunnel in the evening, the CO2 concentration increased to 560 ppm under the bare ground condition and to 500ppm under the mulched ground condition, respectively. At sunrise the CO2 concentration began to decrease again with the increase of the solar radiation intensity, reaching a level similar to that of the surrounding atomosphere of the greenhouse. 5. The CO2 concentration of the atomosphere in the non-hole-poly tunnel with bare ground and non vegetational conditions showed a steady increase to over 550 ppm 3 hours after shutting the tunnel. Thereafter, no change was seen. This suggests that the sand bed provided a considerable supply of CO2 without vegetation.
To clarify the effect of temperature on anthocyanin formation in intact flowers and growth of carnation plants, whole or parts (leaves and flower buds) of plants were exposed to various temperatures. When whole plants were exposed to the temperature treatments of 15°, 20°and 25°C, reduction in the sizes of leaf, petal and corolla, diameter of stem and color intensity of leaf coincided with the high temperature treatment, and the blooming of the 1st flower under high temperature was earlier than that for the low temperature treatment. Anthocyanin content and color intensity of petals also declined with the rise in temperature. When the high temperature treatment was interrupted with low temperature for 6 hours at day or night, the interruption at day stimulated anthocyanin formation as compared with continuous high temperature treatment. On the other hand, when leaves and flower buds were locally exposed to different temperatures, the degree of anthocyanin formation was mainly affected by the temperature of the flower buds. The change of anthocyanin formation after alteration of temperature was rapid under both the exposure of whole plants and the local exposure of flower buds. Sugar content in petals was much higher than that in leaves and most of them was reducing sugar. Effect of temperature on the sugar content was small in petals as compared with leaves.
Carnation cv.‘Coral’was grown in sand culture and fertilized with complete nutrient solutions containing 0, 0.5, 5, 10, 20, 30, 60, 90, 150 and 300ppm Mn. Days from planting to flowering were not influenced by Mn concentrations, but growth was reduced above 30ppm Mn. Mn was most concentrated in the leaves, less in the stems, and least in the petals, and the content in those parts significantly increased as Mn concentrations raised from 0 to 300ppm. Tipburn symptoms on the upper leaves of the plants receiving 60, 90, 150 and 300ppm Mn appeared about 120, 110, 50 and 40 days after treatment, respectively. Thereafter these symptoms, at 150 and 300ppm Mn, developed toward the middle to the lower leaves. Critical Mn concentration in the nutrient solutions, and Mn content in the leaves causing toxicity symptoms were 60 and approximately 2600ppm, respectively. These symptoms were highly correlated with Mn content in the leaves above 60 ppm Mn in the nutrient solutions. Mn distribution was slightly lower in the middle leaves. Elements other than Mn were not influenced by Mn concentrations, except that Fe:Mn in the leaves decreased with increase of Mn levels.
The bulb structure, and the growth periodicity in mid-Japan in matured bulbs of six species of Lycoris were observed. 1. A bulb shows a sympodial branching system, each unit of which is composed of a membranous scale, a number of foliage leaf bases and a ungulate scale in 1/2 alternate arrangement from the base upwards, and terminates in an inflorescence. The number of foliage leaves developed from a nuit of the sympodium, whose bases encircle the axis differed between species, ranging from about 5 in L. radiata to 10 in L. squamigera. 2. At the time of flower initiation, lateral growing points are formed in the axil of the upper two or three leaves. When they carry on growth, the uppermost one grows into the next unit of the sympodium and the lower ones develop to be daughter bulbs. The new unit of the sympodial branch first forms a membranous scale on the same side as the inflorescence. 3. At lifting time, a large bulb is made up of three units or a threeyear-old entity. However the outer half of the leaf bases on a outermost unit have disappeared or became brown and papery. 4. The periodic growth during a year was observed from the middle of March. At this time, each of the species remained in vegetative growth. During the middle and end of April the apical growing point became broader and flatter than before, followed by the formation of two spathes a week later. We deemed this phase as the first sign of floral induction. Difference in the time of the spath formation among species was less than two weeks. 5. Initial of the first floret appears from the end of Aril to the middle of May, in which L. incarnata, L. sanguinea and L. squamigera initiated it somewhat earlier than L. albiflora, L. aurea and L. radiata. The inflorescence growth of the former three species progressed faster than the latter three species. Their first florets formed the pollen tetrad in the early of July and came into bloom in the middle or end of August. While, the latter species attained the pollen tetrad stage in the middle of August and bloomed one month later than the former ones. 6. In all the species, a plastclon of leaf formation on the developing bulb unit was short in the early stage of the development and gradually lengthened towards the termination of leaf formation in the latter part of September. The newly formed leaves, excluding a few upper ones, emerged above grouned together with a few leaves which had been formed in the upper nodes of the preceding unit of sympodium and had been resting until this time. 7. The leaves of L. albiflora, L. aurea and L. radiata emerged in the early of October and entered a period of senescence in the early of May and those of L.incarnata, L. sanguinea and L. squamigera began to February of the next year and withered one month later species.
Young seedlings of Notocactus submammulosus var. pampeanus cut transversely were placed onto transverse cut surfaces of young plants of Hylocereus trigonus. Vascular connection between stock and scion occurred in almost all grafts 20 days after grafting when cut ends of vascular bundles of stock and scion were placed together (Method I). When they were 1 or 3mm apart transversely to each other (Method II or III), vascular connection occurred in only 40 or 10% of grafts. By the Method II, NAA, IAA and 2, 4-D promoted vascular connnection, and also increased the diameter of the vascular bundle connecting those of stock and scion. NAA (100ppm) was most effective when applied three times every three days after grafting. TIBA (0.1% in lanolin), a well-known inhibitor of basipetal transport of auxin, inhibited vascular connection strongly. But, by subsequent NAA (0.01% in lanolin) applications, this inhibitory effect of TIBA was effaced completely. When lanolin with NAA (0.01%) was applied instead of a scion, it also induced a cambium in the area of the tissue between the lanolin and the vascular cut end of the stock. The results suggested that the vascular connection in cactus grafts may be controlled by endogenous auxin of scions.
The effects of balances inside each cation and anion group for aseptic culture of Bletilla striata seeds were examined, using a cation or anion triangle method. Total concentration of the final nutrient media was held to 20 milligram equivalents per liter. To determine the optimal cationic balance, the nitrate, phosphate, and sulfate balance was held to the ratio of 40:10:50 percent of the anionic sum, and the magnesium level was kept at 10 or 30 percent of the cationic sum, but ammonium, potassium, and calcium were varied systematically. And to determine the optimal anionic balance, the ammonium, potassium, calcium, and magnesium balance was held to the ratio of 40:10:40:10 percent of the cationic sum, but nitrate, phosphate, and sulfate were varied systematically. The optimal range of ions expressed in percent of total anion or cation concentration was obtained as follows; NH4+ 16-20 NO3- 66-88 K+ 35-41 H2PO4- 7-23 Ca++ 34-37 SO4-- 4-14 Mg++ 10 One of the optimal nutrient compositions for the growth of Bletilla striata seeds was found to be; Ca(NO3)2 826mg/l Minor elements of Murashige and Skoog medium. KNO3 747mg/l NH4H2PO4 391mg/l Sucrose 20g/l MgSO4•7H2O 172mg/l Agar 10g/l Bletilla striata seeds did not require ammonium ions for germination, but their growth was stimulated by the presence of ammonium ions.
1) Corms taken from plants which had been grown under shade from the three-leaf stage showed earlier sprouting than corms from plants grown under natural conditions. 2) Sprouting of corms from plants whose leaves had been treated with photosynthesis-inhibitors was promoted. The amounts of inhibitors, at Rf values 0.0-0.3 on paper chromatograms developed with isopropanol:ammonium:water (10:1:1v/v), decreased in corms whose mother plants had been treated with the photosynthesis-inhibitors. 3) Corms taken from plants whose leaf bases had been wrapped with aluminium foil from the three-leaf stage showed the eariest sprouting and a smaller amount of inhibitors at Rf values 0.4-0.8 on paper chromatograms.
This paper is a report about the effect of culture medium organic matter on the growth of Cymbidium protocorms. The protocorms, having had their physiological and morphological conditions equalized by sub-culturing 16 times, were cultured in various media. As the basal medium, Knudson′s C solution, White′s mineral salt solution and the Kyoto solution were used. Organic matter such as pepton and juices of banana, apple and potato were added to each of the basal solutions. The following is an outline of the results: (1) When Knudson′s C basal solution was used, the medium containing both banana and apple juice most effectively promoted the growth of protocorms and their shoots and roots. There was a noticeable promotive effect even when banana juice was used alone. (2) When organic matter was added to White′s mineral salt solution, a noticeable promotion of growth was observed in the medium containing both banana and apple juice, but the promotion was not so great as in the medium with banana alone. (3) When Kyoto solution was used as the basal medium, the application of banana juice alone was most effective in promoting the growth of the shoots of protocorms and their roots, followed by the application of banana juice together with pepton. (4) When 15% banana juice was applied to the basal medium, a considerable growth of shoots and roots was observed and well-developed plantlets were obtained. (5) White′s solution enriched with 15% banana juice was the best medium for the growth of Cymbidium plantlets.
The young, immature fruit of satsuma mandarin produced a great amount of ethylene. Starting after a few days off the tree, the fruit began producing ethylene at an increasing rate, rising to a maximum and falling off thereafter. The highest rate was obtained for the fruit harvested June 17. The rate of ethylene production decreased as the fruit increased in weight. For the young fruit harvested in May and June, the high rates of ethylene production were associated with browning of the fruit. For the fruit sampled in July browning was not observed and the increasing rate of ethylene production paralleled that of respiration, followed by yellowing of the rind. The fruit harvested in September and those of all subsequent harvests produced no measurable quantities of ethylene. When young fruits were cut into small pieces, a large quantity of ethylene was evolved during the course of incubation. The smaller the segments the faster the rise in the rate. Flavedo, albedo and pulp tissue separated from the intact fruit also produced ethylene in a great amount. The ethylene production by the excised segments or albedo tissue was markedly prevented by the addition of cycloheximide.