• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.6
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• pp.757-767
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• 1995

This experiment was done to determine the optimum concentration of IAA for root development in plants regenerated from the callus culture of barley embryos. Two concentrations of 2,4-D, 3ppm and 5ppm selected as an optimum among five different concentrations in the previous experiment were used for callus induction and proliferation in this experiment. For callus induction, 3ppm of 2,4-D produced 35.6% in immature embryos and 4.4% in mature embryos, while 5ppm gave 33.8% in immature and 5.6% in mature embryos. Out of 320 immature embryos cultured, 111 embryos were induced to calli and 684 plants were produced from them, while only 16 embryos were induced to calli from 320 mature embryos and 92 plants were restored. The rates of callusing and plant regeneration were 34.7%, 214% in immature embryos and 5.0%, 28.7% in mature embryos, respectively. The average root lengths and root numbers of plants restored from callus at five different IAA concentrations of 0ppm, Ippm, 5ppm, l0ppm and 30ppm were 7.9mm, 3.6; 18.4mm, 5.2; 16.1mm, 3.9; 8.5mm, 3.5 and 6.4mm, 3.4, while plants directly obtained from mature embryos were 14.8mm, 4.9; 4.9mm, 3.6; 4.3mm, 3.1; 3.6mm, 2.6 and 3.2mm, 2.1, respectively. Therefore, 1ppm gave the best result for the root. promotion in callus, whle 0ppm, a control, gave the largest root developmemt in embryos. High concentration of lAA(30ppm) in callus and any exogeneous supplement of lAA in embryos negatively affected to the root lengths and root numbers. Genotypic effect was also observed in given four varieties, Bruce, Klages, Olbori and Albori. For chromosome doubling, when 0.1% colchicine was applied on 428 plants under three different conditions such as air circulation, temperatures and growth stages, 319 plants of doubled haploids were obtained so that the rate was 74.5%

• Horticultural Science & Technology
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• v.30 no.3
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• pp.250-255
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• 2012

The effect of different source silicon ($CaSiO_3$, $K_2SiO_3$, and $NaSiO_3$) and their application methods (foliar application and subirrigation) on the growth of potted kalanchoe was investigated. Rooted terminal cuttings of Kalanchoe blossfeldiana 'Peperu' were transplanted into 10.5 cm plastic pots containing a commercial growing medium. Then, a nutrient solution, containing 0 or $50mg{\cdot}L^{-1}$ Si as $K_2SiO_3$, $Na_2SiO_3$, or $CaSiO_3$ and adjusted to EC 1.4-$1.6mS{\cdot}cm^{-1}$ and pH 6.0, was supplied through subirrigation along with the nutrient solution or by a foliar application. Plants were grown in a glasshouse under a mean temperature of $23^{\circ}C$ and RH of 70-80%. After 12 weeks of cultivation, plant growth characteristics and leaf tissue contents of P, K, Ca, Mg, Na, S, and Si were measured. Both subirrigational supply and foliar application of Si decreased the plant height and flower stem length. However, the plant condition in the foliar application resulted in disease-like soft rot on the leaf. Among three silicon sources tested, $CaSiO_3$ supplied through a subirrigation system increased shoot tissue contents of Si and chlorophyll as compared to the $Na_2SiO_3$ or $K_2SiO_3$ treatment. Shoot tissue contents of Ca, K, and Na increased when the plant was supplied with $CaSiO_3$, $K_2SiO_3$, and $Na_2SiO_3$, respectively. Subirrigational supply of $K_2SiO_3$ and $NaSiO_3$ decreased the shoot tissue contents of Ca and Mg, and K and Ca, respectively. Therefore, $CaSiO_3$ supplied through a subirrigation system could improve plant quality of kalanchoe 'Peperu' making compact potted plants.

• Horticultural Science & Technology
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• v.32 no.4
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• pp.421-426
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• 2014

To investigate the optimal size of fruit bearing branches (FBBs) of 'Kawanakajima Hakuto' peach (Prunus persica Batsch) for production of high quality fruits, we evaluated shoot growth and fruit characteristics relative to FBB direction and thickness. FBB diameter, shoot length, fruit weight, and soluble solids content (SSC) averaged 6.9 mm, 32.6 cm, 333.6 g, and $11.2^{\circ}Brix$, respectively. Coefficients of variation of FBB diameter and shoot length were high as 35.8% and 75.3%. The highest frequency values revealed that 76.4% of FBBs had a diameter below 9.0 mm, 70.0% of shoot lengths were less than 40 cm, 24.8% of fruits were 310-340 g, and 66.9% of SSCs were $10.5-12.5^{\circ}Brix$. Shoot length and SSC were significantly affected by FBB diameter without direction, and fruit weight was significantly affected by interaction of FBB diameter and direction. There was a negative correlation ($r^2=0.094^*$) of FBB diameter and fruit weight with upward FBB directions, whereas FBB diameter and fruit weight were positively correlated ($r^2=0.246^{**}$) with downward FBB direction. With thick FBB diameter, shoot length, and SSC were significantly increased, but fruit weight was decreased. Therefore, downward FBBs below 9.0 mm in thickness are suitable for producing high-quality fruits of 'Kawanakajima Hakuto' peach.

• Journal of Korean Society of Forest Science
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• v.83 no.3
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• pp.311-321
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• 1994

Experiments were conducted to evaluate the efficacy of ground and foliar sprinkling of natural water for control of the pine needle gall midge, Thecodiplosis japonensis, by disturbing the reproductive behavior of adults such as copulation and oviposition. Diurnal ground spray for whole area application and foliar spray for single tree treatment were tested at day time during the period of adult emergence. The results obtained are as follows : 1. The population density of overwintering larvae in soil was not affected by the water spray during the adult emergence period. 2. Spraying the water showed no effect on the whole period and number of adult emergence, but retarded early emergence and facilitated Late emergence. The difference in the emerging time by 50% emergence day was approximately 7 days. 3. Ground spray was significantly different from control in gall formation rates but was not sufficient for effective control. As a single-tree treatment, the foliar spray was found to be highly effective for control of the pine needle gall midge, Average gall formation of spray plots and untreated ones were 2.6% and 38%, respectively ; control value exceeded 90%. 4. Ground spray of water was not effective in reducing larvae in gall of needle. Foliar spray, however, reduced 45% of larval numbers. 5. Foliar spray accelerated shoot growth by 15%-18%. 6. Foliar spray was highly effective for the control of sucking insects, such as mites and aphids on pine trees.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.319-325
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• 2018

The aim of the present study was to determine the influence of different fertilizer combinations on the growth, yield, and fruit quality of 'Duke' blueberry cultivar and the water quality of growth medium. The experiment was carried out with three year old 'Duke' blueberry bushes which were cultivated in containers ($60{\times}80{\times}40cm$) filled with 130 L peat moss and 40 L pearlite (v/v). Sawdust was used as the mulch in growth containers. Three different fertilizer combinations (FC) i.e., FC-1 consisted with standard solution, FC-2 consisted with nitrogen reduced by 10% from FC-1, and FC-3 consisted with nitrogen reduced by 20% from FC-1 were tested while, the ground water used as the control. The effects of different fertilizer combinations on shoot diameter, shoot length, number of shoots, leaf length, SPAD value (the relative content of chlorophyll), berry weight, soluble solids content, titratable acidity, and yield per bush in 'Duke' blueberry were examined. Also, the effects of different fertilizer combinations on pH, EC, $NH_4$ and $NO_3$ in 'Duke' blueberry growth medium were monitored. The highest pH and lowest EC, $NH_4$ and $NO_3$ in growth medium was recorded with control treatment during the experiment period. The maximum shoot diameter (3.7 mm) and shoot length (35.7 cm) was recorded for the FC-1. Highest number of shoots (47%) were recorded from 'Duke' blueberry bushes supplemented with FC-1 compared to other treatments. The fertilizer combinations supplemented with nitrogen showed significant influence on leaf length and SPAD value compared to control 'Duke' blueberry bushes. However, the fruit quality attributes, i.e., berry weight, soluble solids content, and titratable acidity were not significant different among fertilizer treatments. The significantly highest yields per bush were recorded for FC-1, FC-2, and FC-3, as 2.2, 2.9, and 2.7 kg, respectively compared to control (0.2 kg). Although, the FC-1 was supplemented with highest nitrogen content it resulted low yield per bush while having high number of shoots and vigorous growth.

• Korean Journal of Soil Science and Fertilizer
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• v.46 no.1
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• pp.53-57
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• 2013

A severe defoliation by typhoon in early autumn reduces fruit quality for the current season and reserve accumulations for the next season. This study was conducted to determine the effects of foliar applications during the autumn on alleviating the damages after defoliation. Leaves of 2-year-old 'Fuyu' trees, grown in 50-L pots under a rain-shelter, were 75%-defoliated on September 9. In mid-September and early October, trees were treated either with eight foliar applications of urea or with four alternating applications of urea and $KH_2PO_4$ (urea + KP application), all at 0.5% (w/v). Trees untreated after the defoliation served as the control. The urea applications slightly increased N and P concentrations of the leaves collected on November 6, while urea + KP applications significantly increased P and K concentrations. Foliar applications did not affect fruit growth, but tended to decrease skin coloration. Fruit soluble solids increased by 1.5 and $1.0^{\circ}Brix$ for urea and urea + KP applications, respectively. There was a significant increase in dry weight of fine root for the foliar application treatments but not in those of aerial woods and larger roots. With the foliar applications, N concentration tended to increase in the permanent organs but not P and K, whereas soluble sugars and starch notably increased in shoot, trunk, or fine root regardless of the different applications. Results indicated that the foliar applications could partially help to restore fruit quality and carbohydrate accumulations in the defoliated trees.

• Korean journal of applied entomology
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• v.24 no.3 s.64
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• pp.123-127
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• 1985

Incidence of the Fusarium wilt caused by F. oxysporum f. sp. vasinfectum of sesame (var. Kwangsan) was remarkably influenced by seeding date and mean air temperature in the field of two or three year's continuous cropping with sesame in 1983 and 1985. Sesame were seeded on six different dates from April 20 to July 5. Air temperature was checked daily at the meteorological station near the experimental field. Low($16{\sim}20^{\circ}C$) and high temperature($20{\sim}25^{\circ}C$) periods were provisionally devided, based on every ten-day mean daily temperature during field experiment for last ten years, which corresponded to before and after June 15 in Jinju, Gyeong-nam. Infection rates were 83.7%, 68.2% and 59.4% in the plants grown for 55 days (seeding date: April 20), 40 days(May 5) and 25 days(May 20) under low temperature. On the other hand, infection rates were below 3% in those plots seeded during high temperature period. The longer the growth period exposed to low temperature, the higher was infection rates. It is interesting to note that 40 days old seedling or older are prone to severe infection compared to the younger ones, in higher temperature of $20{\sim}25^{\circ}C$. Therefore, seedlings in vegetative growth stage are less prone to infection than these in reproductive growth stage. The result showed that air temperature during sesame growth was one of the most important factor affecting the incidence of Fusarium wilt. This suggested that sesame crop, which is of tropical origin, has been predisposed to Fusarium wilt, when the plants were exposed to low temperature of $16{\sim}20^{\circ}C$.