We developed a method of evaluating the resistance of strawberry to anthracnose disease (Glomerella cingulata) by testing the self-established seedlings of the cultivar. The survival rate of the seedlings decreased rapidly after spray inoculation with fungal spores, but there was no significant difference in survival rates from 20 to 34 days after inoculation. The survival rates 34 days after inoculation increased with increasing seedlng age at the time of inoculation, up to a maximum at 2 weeks after germination. We thus recommend using seedlings that had germinated more than 2 weeks before inoculation and then calculate survival 20 days after inoculation. There were strong correlations between disease indices calculated using vegetatively propagated plants and the survival rates after inoculation of self-established seedlings. This study showed that evaluation using self-established seedlings is effective.

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The effect of global warming on the flowering of satsuma mandarin grown in Japan was investigated in eight cultivars. In a green house that simulated a warming condition, flowers tended to bloom early and flowering periods were prolonged in all cultivars. Increase in leafless flower in the green house caused an increase in the total number of flowers compared to those in the open-field, especially in early- or very early-maturing cultivars. The ratio of the starch concentration to total carbohydrates of the roots positively correlated with the number of leafless flowers, and negatively correlated with the number of leafy flowers. Abscisic acid (ABA) concentration in the leaf during winter correlated positively in all cultivars with the number of leafless flowers or the percentage of leafless flowers to total number of bud burst and was further emphasized by increased ABA from Oct. till Dec. or Jan. These findings suggested that global warming may increase leafless flowers, but decrease leafy flowers in satsuma mandarin grown in the main production areas in Japan, especially in early- or very early-maturing cultivars.

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To investigate the effects of the application of apple prunings compost on the growth of apple nursery trees and on the chemical properties and aggregate structure of soil, three kinds of composted apple prunings were applied to soil in Wagner pots planted with apple nursery trees. The composts used were piled for one year and two years respectively, plus recycled-use compost, i.e. compost mixed with highly decayed apple prunings compost and piled for one year. For control purposes, plots treated with rice-straw compost and without compost were also prepared. The growth of apple nursery trees on the three plots treated with composted apple prunings was similar to that on the plot treated with rice-straw compost. The chemical properties of the soil were improved by the application of composted apple prunings, especially the recycled-use compost, which increased the exchangeable bases and available nitrogen contents of the soil. While faster formation of soil aggregates by composted apple prunings was not ascertained, organic matter derived from the applied compost clearly tended to accumulate in soil aggregates. These findings show that the application of composted apple prunings promotes the growth of apple nursery trees and is an effective method of improving the chemical properties of soil.

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We studied the influence of a 2°C increase in air temperature on physiological fruit drop in Citrus using a growth chamber for two months after full bloom. One room of the growth chamber was maintained at the standard temperature (control), while the other was maintained at 2°C higher than the control (+2°C treatment). The average temperature was changed every ten days. In ‘Okitsu wase’, ‘Ishiji’, ‘Shirakawa’ Satsuma mandarin (Citrus unshiu Marcow.), and ‘Shiranui’ [(Citrus unshiu Marcow. × C. sinensis Osbeck) × C. reticulate Blanco], physiological fruit drop occurred more intensively in +2°C treatment than in the control after 10–20 days of full bloom. At the end of the experimental period, the physiological fruit drop ratio in plants receiving +2°C treatment was higher (5%) than that in controls for ‘Okitsu wase’ and ‘Ishiji’. In ‘Miyagawa wase’ and ‘Sasebo unshiu’ Satsuma mandarin, in which number of fruit was controlled by artificial fruit thinning, physiological fruit drop also occurred more intensively in plants receiving +2°C treatment than in controls after 10–20 days of full bloom. Especially in ‘Sasebo unshiu’ at the end of the experimental period, the difference in the physiological fruit drop ratio between plants receiving +2°C treatment and controls was larger (26%) than that in ‘Miyagawa wase’. In ‘Miyagawa wase’ and ‘Sasebo unshiu’ fruit diameter of plants receiving +2°C treatment was larger than that of controls. These findings suggested that with acceleration of fruit enlargement, and physiolosical fruit drop were both promoted by a 2°C increase in air temperature after full bloom.

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This study investigated the effects of planting density, container size and period of raising seedlings on the growth and flowering of non-pinched snapdragons. In experiment 1, seeds were sown in July, September or February, and seedlings were planted at a density of 50 or 100 plants per square meter. When sown in July and September, plant heights exceeded sufficiently 100 cm to satisfy the highest quality of cut flowers from that locality. Weight of cut flowers and the number of axillary buds decreased at the higher planting densities. But there was no effect of planting density in a culture system sown in February. Eexperiment 2 investigated the effects of container size (deep or shallow type) and nursery period (21, 32 or 43 days) on the growth and flowering of non-pinched snapdragon cultivars ‘Maryland Pink’ and ‘Light Pink Butterfly II’. Days to anthesis and the length of cut flowers of ‘Maryland Pink’ decreased in deep type containers. The growth of ‘Light Pink Butterfly II’ was not affected by the container size. There was no adverse effect of nursery periods up to 43 days on either cultivar.

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This study investigated how leaf net photosynthesis and growth of trees of ‘New Jonagold’ apple (Malus domestica Borkh.) trees vary according to rootstocks: JM1, JM7 and JM8 (M. prunifolia Borkh. var. ringo Asami × M. pumila Mill. var. paradisiaca Schneid.), and virus-free M.9 (M. pumila Mill. var. paradisiaca Schneid). The results of the experiment showed that on detached and watered shoots, there were no significant differences among the four rootstocks in the photosynthesis and transpiration rates. In contrast, the photosynthesis and transpiration rates and leaf stomatal conductance for JM1 exhibited significantly lower levels than JM7, JM8 and virus-free M.9 on field-grown trees, although a midday depression occurred for all of the rootstocks. Regarding the growth of trees, the results demonstrated that the trees grafted on JM7 and JM8 grew significantly bigger than those on virus-free M.9, while trees on JM1 demonstrated significantly less growth. These findings suggest that certain rootstocks have an observable effect on the degree of midday depression of leaf photosynthesis depending on drought stress conditions. These findings also imply that apple trees grafted onto JM1 are substantially dwarfed since the JM1 rootstock is subject to greater midday depression in leaf photosynthesis.

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In tourism farm where fruits are the main product, there are a lot of farms that close in winter when the ‘Satsuma’ mandarin seasons is over. So macadamia trees are favorable for prolonged opening of a tourist farm throughout autumn into winter because macadamia nuts can be kept on the tree even after maturity. We applied four macadamia cultivars, ‘Burdick’, ‘Beaumont’, ‘Cate’ and ‘Cooper’ to test their yield and changes of quality during ripening period in Wakayama prefecture. The yield was low in all cultivars observed but it remained possible to harvest good quality nuts with a high ratio of edible portion and high oil content of the dry kernel, and remained on the trees until early February. The fresh weight of kernel, the ratio of edible portion, and the oil content of the dry kernel in the beginning of February were about 4 g, 36% and 70%, respectively. The quality scarcely changed compared with that of nuts harvested the previous October.

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Effects of day and night temperatures and shading on the development of ovules and pea pods (Pisum sativum L. ‘kishu-usui’) were investigated during the entire winter cropping season. Percentages of unfilled pods increased between February and March were increased by shading treatment in which the light intensity was 77% of the control valve. Occurrence of unfilled pod was associated with percentage of underdeveloped ovules, but not that of abortive ovules in the pod. Compared with that at 7°C at night, the weight of single ovule was decreased at 3°C, but did not affect the percentage of developed ovules. Under shaded condition with a light intensity that was 50% of control, unfilled pods increased at a day temperature of 13°C, but not at 17.5°C. These findings indicate that the percentage of unfilled pods can be enhanced by a low day temperature under low light intensity.

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We investigated the effects of nitrogen fertilizer levels in nutrient solution applied before/after flower budding on blasting in the winter flowering of Eustoma grandiflorum (Raf.) Shinn. Application of a solution with a high nitrogen concentration after flower budding increased the number of flower buds and fresh weight of cut flower, whereas the rate of flower-bud blasting was increased by application of high concentration nitrogen. The relationship between the rate of flower-bud blasting and the nitrogen concentration in the whole plant showed a linear function. The rate of flower-bud blasting was found to be proportional to the fresh weight of the cut flower. The increased nitrogen levels applied after flower budding induced flower-bud blasting at the upper nodes as well as the lower nodes. As a result, flowering was delayed by blasting. Moreover, the total biomass production increased with the increase in nitrogen levels after flower budding. When the flower bud developed under low sunlight in winter, i.e., from December to January, with application of high concentration nitrogen, the flower-bud blasting was caused by the higher dry matter partition in the leaves and shoots than that in the flower bud.

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Different organs of chinese cabbage and cabbage were analyzed for four calcium (Ca) components, water–, 1N NaCl–, 2% acetic acid– and 5% HCl–soluble Ca. Among these forms of Ca, water-soluble Ca is highly degestible by humans. In Chinese cabbage and cabbage, the outer leaves had the highest concentration of total and water-soluble Ca, compared to head-formed leaves and stem. Head-formed leaves of these vegetables had lower concentrations of water-soluble Ca than turnip rape. However, total and water-soluble Ca concentrations in the outer leaves of cabbage were 1.84 mg·g⁻¹FW and 1.26 mg·g⁻¹FW, which were 2.1, 2.9-fold greater than those in turnip rape, respectively. Furthermore, the outer leaves of Chinese cabbage had the same concentrations of total and water-soluble Ca as turnip rape. These findings suggest that the outer leaves of Chinese cabbage and cabbage are useful materials for juice and other new products.

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To clarify a critical concentration of excess boron (B) in nutrient solution for hydroponically cultured tomato, the influences of excess B on growth, photosynthesis and fruit maturity were investigated. In tomato topped at the first truss, B concentrations higher than 2 ppm in nutrient solution resulted in a significant increase in leaf B concentration. At the fruit developmental stage, fresh weights of leaf and fruit were suppressed at 8 ppm and 4 ppm B in nutrient solution, respectively. Photosynthetic rate, respiration rate and stomatal conductance decreased with excess B at 4 ppm or higher concentration from the first truss flowering stage to fruit developmental stage. When tomato was topped at the second truss and limited to two fruits in each truss, excess B did not affect fruit growth or maturation in the first truss. However, fruit size and Brix were reduced in the second truss. These may be caused by decrease in the photosynthate distribution to fruit in the second truss because of the decrease in photosynthetic activity. Furthermore, excess B could promote fruit maturity in the second truss because of production of ethylene with increase in injured leaves. Based on these results, we suggest that the critical concentration of B in nutrient solution is 4 ppm for long-term hydroponic cultivation of tomatoes.

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‘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. The water potential of the leaf decreased only after 20 days of water stress. Twenty days of water stress increased first-flush flowers compared with that in non-treated control trees. The ABA level increased in the leaves and the roots subjected to 10 and 20 days of water stress. Total sugars in the root increased trees undergoing 10 or 20 days of water stress, while those in the leaf and shoot tended to increase only after 20 days of water stress. However, starch contents of the leaf and shoot tended to decrease in water-stressed trees. These findings indicate that increase in total sugars in the root and a continuous high ABA level under water stress after termination of new shoot growth significantly increases the number of first-flush flowers.

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This study was carried out to investigate the possibility of accelerating flowering by applying chilling to corms before planting in Ixia ‘Venus’. Flowering was most advanced by chilling corms with peat moss under wet conditions, and the optimum chilling temperature was 8–12°C. When corms were subjected to chilling at 8°C for 4–8 weeks under wet conditions, flowering became earlier in those chilled for longer periods. When corms were stored at 20°C for various durations under dry conditions before chilling at 8°C for 8 weeks, sprouting became earlier in those stored for longer periods and they all flowered and exhibited full chilling response by chilling after storage for 6 weeks or more. Compared to those stored at 20°C, when corms were stored at 30°C, sprouting was delayed and flowering percentage decreased with increasing storage period. Based on these results, the earliest flowering was obtained when corms were stored at 20°C for 6 weeks or more under dry conditions immediately after digging and then chilled at 8°C for 8 weeks under wet condition. It was also suggested that flowers could be harvested in late December when chilling started in early August.

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To determine preventive measures for strawberry damage from shock during transport, we measured the shock frequency and level during actual transport using an acceleration recorder and determined these effects on the commercial quality of fruit. In addition, we investigated cushioning materials for use in reducing both shock and quality loss during transport. Shock was found to be concentrated in the bottom layer of boxes. The effect of shock severity and frequency on quality could be shown as a power approximate curve (R² = 0.98) and used to deduce quality loss from shock. Using this curve, the relationship between thickness of cushioning materials and the degree of reduction in quality loss of the fruit was determined. Based on these findings, packaging could be designed to reduce damage caused by shock during strawberry transport.

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The symptom of Verticillium black spot in Japanese radish (Raphanus sativus L.) is black discoloration at the vascular bundle of the root: However, it is difficult to detect the symptom by visual inspection. Thus diseased roots are often mixed with normal roots after inspection in packinghouses. So we attempted to develop a nondestractive determination method using visible (VIS) and near-infrared (NIR) spectoroscopy under practical conditions. The spectra of radish roots were continuously measured by transmittance mode: the scanning range was 450-1,000 nm. Measured roots were then cut and the degree of symptom was converted to an index of 0 (no symptom) to 3 (severely affected) by visual inspection of the cut root. Partial least squares regression was carried out relative to the indices to the second derivative spectra. In a validation set, the standard error of prediction for the index was 0.299 (R = 0.958, n = 70). For each root without the symptom, the predicted indices were less than one, and for 91% of the roots with the symptom, the predicted indices were more than one. Using this method, the roots with an index of 0 could be completely separated from those with an index 2 or higher. It is suggested that VIS/NIR spectroscopy is an effective tool for accurate and rapid elimination of radish roots with the internal symptom of Verticillium black spot.

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‘Le Lectier’ pears treated with low-temperature (refrigerated storage) at 2–3°C for 0, 10, 30, 60, or 90 days after harvest showed changes in elasticity index, flesh firmness, fresh weight, peel color index and soluble solid concentration during ripening at 10°C. During low-temperature treatment, the fruit did not reach the edible ripeness stage, although the metabolic activities such as yellowing of the peel and softening of the flesh did occur under the low-temperature condition at 2–3°C. After low-temperature treatment at 2–3°C, the peel color index and soluble solid concentration of the fruit increased during ripening at 10°C, and the elasticity index, flesh firmness and fresh weight of the fruit decreased. Fruit receiving low-temperature treatment for 10 or 30 days ripened normally, and the fleshy substance of the fruit developed a melting quality. However, fruit receiving low-temperature treatment for 60 or 90 days rotted from the fruit stalk during ripening. The flesh of the fruit receiving low-temperature treatment for 60 days softened, but the fleshy substance of the fruit did not reach a melting quality. Therefore, it was suggested that ‘Le Lectier’ pears are not able to ripen normally when fruit was stored for 60 days or longer at a low temperature of 2–3°C. In addition, the weight loss correlated with the elasticity index during ripening. This finding suggests that the elasticity index is strongly affected by weight loss (moisture loss).

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Evaluation of functional properties of the chili pepper varieties ‘Rocot’ (C. pubescens) and ‘Botankoshou’ (C. annuum L.), which are suitable for growing in cool areas. The fruit of ‘Botankosho’ shows a low capsaicinoid concentration at the same carotenoid concentration as ‘Kyonami’ which is one of the sweet pepper varieties. The immature fruit of ‘Botankosho’ shows higher total phenolics content and antioxidative than mature fruit of the same variety. These plants also show wide variations among strains with regard to total phenolic concentrations and antioxidative ability. The mature fruit of the strain BK-4 and the immature fruit of the strain BK-2 show higher GABA concentrations than comparable varieties. ‘Rocot’ shows wide variation in capsaicinoid concentrations and higher content than ‘Takanotsume’ which is a well-known pungent variety that is popular in Japan. The mature fruit shows higher carotenoid concentrations than ‘Shishitou’ and ‘Takanotsume’. The mature fruit also show a higher total phenolic concentration than comparable varieties, but the same GABA concentrations as comparable varieties. Some strains of ‘Botankosho’ and ‘Rocoto’ show higher concentrations of functional properties and show wide variation among strain. Therefore, we expect to use ‘Botankosho’ and ‘Rocoto’ to breed new varieties for cool areas, which add to the functional properties.

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