Language：Japanese   Publisher：Meiji University  

'Meiwa' kumquat (Fortunella crassifolia Swingle) trees were subjected to water stress in order to increase first-flush flowers by withholding water until the soil water content reached about 30% and was maintained for 10 or 20 days. All treatments of water stress increased first-flush flowers as compared with non-treated control trees. The total sugars and ABA level increased in the roots subjected to 10 days of water stress, while total sugars in root, leaf and shoot, and the ABA level in root increased in 20-day water stressed trees. On the other hand, starch contents of root, leaf and shoot decreased in water stressed trees. GA-like substances in leaf were decreased by water stress or re-irrigation though temporal increase in those of 20-day stressed trees were observed. The positive correlation was observed between the number of first-flush flowers and the ABA level of leaf. These results indicate that increased total sugars and ABA level under water stress after termination of new shoot growth increases the number of first-flush flowers significantly.

CiNii Research

researchmap

Other Link： http://agriknowledge.affrc.go.jp/RN/2010742983

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

'Meiwa' kumquat (<I>Fortunella crassifolia</I> Swingle) trees were subjected to water stress in order to increase first-flush flowers by withholding water until the soil water content reached about 35% and maintained 2 weeks, 3 weeks and 4 weeks. In all treatment subjected to water stress increased first-flush flowers as compared with non-treated control trees. The number of first-flush flower increased with the prolonged duration of water stress. Early fruit develop-ment in water stressed trees were promoted and fruit diameter at harvest increased significantly. In rind color of the fruit at harvest, a value of the rind increased significantly suggested promotion of fruit maturation in water stressed trees. Total soluble solids of the fruit in water stressed trees were not different from the control trees, while yield per tree in water stressed trees were significantly increased as compared with the control trees. These results indicate that the number of first-flush flowers increases under water stress after termination of new shoot growth and yield increases significantly without degrading fruit quality.

DOI： 10.2525/ecb1963.42.241

CiNii Research

researchmap

Language：English   Publishing type：Research paper (scientific journal)  

DOI： 10.2525/ecb1963.40.277

CiNii Research

researchmap

Language：Japanese   Publishing type：Research paper (scientific journal)   Publisher：Japanese Society of Agricultural, Biological and Environmental Engineers and Scientists  

Effect of water stress on flowering of 'Meiwa' kumquat trees (<I>Fortunella crassifolia</I> Swingle) was examined to establish a cultivation system for the first-flush flowers. Water stress was established by withholding water until the soil water content reached 45% for moderate water stress treatment, and 35% for severe water stress treatment. Although three sequential flowerings were observed on the control trees, only one flowering was observed on the water-stressed trees. In the control plot, flowering of the first-flush flowers began on 28 June, and about 10 flowers opened per day. Flowering of the second-flush flowers began on 6 July and the number of flowers opened per day reached 300. In moderate water stress treatment, flowering began on 25 June, and lasted until late July without interruption. Therefore, it was difficult to distinguish between the first- to third-flush flowers. In severe water stress treatment, flowering of the first-flush flowers began on 28 June and the number of flowers opened per day reached more than 200. Water stress did not affect fruit growth or quality of fruit. These results indicate that the number of first-flush flowers increases under water stress after termination of new shoot growth and that the required duration of water stress is about 2 weeks.

DOI： 10.2525/ecb1963.38.105

CiNii Research

researchmap

Language：English   Publishing type：Research paper (international conference proceedings)  

Web of Science

researchmap

Language：Japanese   Publisher：THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE  

Photosynthetic and root respiration rates were investigated in relation to tree growth of four 7-year-old Japanese persimmon (<I>Diospyros kaki</I> Thunb.) cultivars. The differences in ecological characteristics and adaptability to warm climate among the cultivars are discussed.<BR>1. Increases of trunk girth during the growing season were greater in the early-maturing cultivars 'Tone wase' and 'Nishimura wase' than they were in the relatively latematuring cultivars 'Fuyu' and 'Hiratanenashi'. In autumn, the total sugar contents of the non-bearing 'Fuyu' shoots were highest, whereas its starch contents were lowest among the 4 cultivars.<BR>2. The photosynthetic rate of a single leaf in early July was high in 'Fuyu' and equally low in 'Hiratanenashi' and 'Tone wase'. In early August, however, photosynthetic rates were high in 'Hiratanenashi' and 'Tone wase' and low in 'Nishimura wase'.<BR>3. There were no significant differences in seasonal changes in root respiration rate among the cultivars. However, in mid-August, the root respiration rates at 30 °C were lower in 'Fuyu' and 'Nishimura wase' than they were in 'Hiratanenashi' and 'Tone wase'; there were no differences at 25 °C. These results show that tree growth of the early maturing cultivars was greater than that of relatively late-maturing cultivars in the warm climate; 'Hiratanenashi' and 'Tone wase' which maintain higher photosynthetic rates during the summer seem to be more adaptable to the warm climate than the other two cultivars.

DOI： 10.2503/jjshs.64.757

CiNii Research

researchmap

Other Link： http://agriknowledge.affrc.go.jp/RN/2010540633

Language：Japanese   Publisher：THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE  

Photosynthetic rate and shoot characteristics were investigated in relation to the tree vigor on 6 cultivars of 5 or 7-year-old very early-ripening Satsuma mandarin (<I>Citrus unshiu</I> Marc.), to discuss the differences of the ecological characteristics among the cultivars.<BR>1. There were no distinctive differences in thickness of the leaf and the palisade tissue among the cultivars. However, in 'Hashimoto wase', both the leaf and the palisade tissue were somewhat thinner than those of the other cultivars. Stomatal density of the leaf varied among the cultivars. Density of stomata was the highest in 'Tanaka wase' and lowest in 'Hashimoto wase' of all the cultivars studied.<BR>2. Photosynthetic rates determined from June to July were higher and maintained so in 'Ichifumi wase' and 'Kusumoto wase'. In 'Tanaka wase' and 'Douwaki wase', photosynthetic rates decreased markedly during this period. It seemed that 'Tanaka wase' and 'Douwaki wase' are not adapted to high temperatures.<BR>3. Differences in the seasonal changes of photosynthetic rates among the cultivars were not clear. In all the cultivars, photosynthetic rates reached maximum at September, then decreased gradually. However, in 'Tanaka wase', 'Yamakawa wase' and 'Kusumoto wase' the rate of decrease of photosynthetic rate after September seemed slower than that of the other cultivars. The maximum photosynthetic rates was high in 'Tanaka wase', 'Kusumoto wase', 'Ichifumi wase' and 'Yamakawa wase', whereas in 'Hashimoto wase', the maximum photosynthetic rate was always the lowest.<BR>4. Shoot growth after summer pruning was greater in 'Ichifumi wase' and 'Kusumoto wase' than in that of other cultivars. Furthermore, in 'Ichifumi wase', the average final shoot length was the longest which resulted in the greatest total shoot growth. 'Douwaki wase' and 'Hashimoto wase' produced fewer shoots, so that their total shoot growth was minimal.<BR>The correlation between photosynthetic rate and total shoot growth indicates that tree vigor is related to photosynthetic rate as measured under field conditions.

DOI： 10.2503/jjshs.60.805

CiNii Research

researchmap

Other Link： http://agriknowledge.affrc.go.jp/RN/2010472134

Publisher：THE JAPANESE SOCIETY FOR HORTICULTURAL SCIENCE  

Characteristics of photosynthesis and transpiration of a single leaf or seedlings of Citrus species were compared to clarify the responses to climatic conditions of Citrus species.<br>The light compensation point of a single leaf was 1.5 to 3.5klx, which was similar in all species tested. There were remarkable difference, on the other hand, in the light saturation point among the species tested. That is, it was 10 to 20klx in 'Morita' Navel orange, 30 to 40klx in other several species and seemed to be 50klx or more in 'Iyo'.<br>The optimum temperature for photosynthesis of a single leaf was about 25°C, though there was little difference depending on temperature at 20 to 35°C, in Wase and Common Satsuma mandarin. It was, however, a little higher, i.e. about 30 °C, in 'Ohta' Ponkan and 'Kawano' Natsudaidai.<br>The photosynthetic characteristics of the seedlings were similar to those of a single leaf, except that the light compensation point was slightly lower and light saturation point was higher than those of a single leaf.<br>The transpiration rate increased as temperature rose up to 30°C, decreasing at 35°C to a certain extent depending on the species. The transpiration rate of a single leaf of 'Morita' Navel orange was hardly dependent on the temperature. It was suggested, therefore, 'Morita' Navel orange had a typical characteristic as to the temperature response of transpiration rate.

DOI： 10.2503/jjshs.54.315

CiNii Research

researchmap

Other Link： http://agriknowledge.affrc.go.jp/RN/2010340276